From 137ebcebec0701818e55a6edc3b6f637c6121cbd Mon Sep 17 00:00:00 2001
From: Steve Boyd <emteknetnz@gmail.com>
Date: Tue, 15 Nov 2022 18:20:54 +1300
Subject: [PATCH] API Stop using deprecated API

---
 _config.php                                   |   4 -
 _config/i18n.yml                              |   4 +-
 src/Control/CookieJar.php                     |   3 -
 src/Control/Director.php                      |   2 +-
 src/Control/Email/Email.php                   | 359 ++++++++++--------
 src/Control/Email/SwiftMailer.php             |   4 +-
 src/Control/Email/SwiftPlugin.php             |   4 +-
 src/Control/HTTP.php                          |  36 +-
 src/Control/Middleware/FlushMiddleware.php    |   8 +-
 .../Middleware/HTTPCacheControlMiddleware.php |   5 +-
 .../URLSpecialsMiddleware/FlushScheduler.php  |   7 +-
 src/Control/RSS/RSSFeed.php                   |   4 +-
 src/Control/RequestProcessor.php              |   4 +-
 src/Control/Session.php                       |   2 -
 src/Control/SimpleResourceURLGenerator.php    |   5 +-
 src/Core/BaseKernel.php                       |  46 +--
 src/Core/Convert.php                          |   2 +-
 src/Core/Manifest/ClassLoader.php             |   4 +-
 src/Core/Manifest/ClassManifest.php           |   4 +-
 src/Core/Manifest/ManifestFileFinder.php      |   5 +-
 src/Dev/Deprecation.php                       | 177 ++++++---
 src/Dev/FunctionalTest.php                    |  21 +-
 src/Dev/SapphireTest.php                      |  16 +-
 src/Dev/Tasks/MigrateFileTask.php             |   9 +
 .../GridFieldAddExistingAutocompleter.php     |   2 +-
 src/Forms/GridField/GridFieldExportButton.php |   2 +
 src/Forms/GridField/GridFieldFilterHeader.php |   9 +-
 src/Forms/TreeDropdownField.php               |   5 -
 src/Forms/UploadReceiver.php                  |   5 +-
 src/ORM/ArrayList.php                         |   8 +-
 src/ORM/Connect/DBSchemaManager.php           |   4 -
 src/ORM/Connect/MySQLTransactionManager.php   |   7 -
 src/ORM/DataObject.php                        |   5 -
 src/Security/CMSSecurity.php                  |   2 +-
 src/View/SSViewer.php                         |   7 +-
 src/i18n/i18n.php                             |   1 -
 .../Forms/GridField/GridField_Item.ss         |   2 +-
 tests/php/Control/ControllerTest.php          |   2 +-
 tests/php/Control/DirectorTest.php            |   4 +
 tests/php/Control/Email/EmailTest.php         |   4 +-
 tests/php/Control/Email/SwiftMailerTest.php   |   2 +-
 tests/php/Control/Email/SwiftPluginTest.php   |   8 +-
 tests/php/Control/HTTPRequestTest.php         |   7 +
 tests/php/Control/HTTPTest.php                |  13 +
 tests/php/Control/SessionTest.php             |   4 +-
 tests/php/Core/ConvertTest.php                |  18 +-
 tests/php/Core/Manifest/ModuleTest.php        |   4 +
 tests/php/Core/ObjectTest.php                 |  13 +
 tests/php/Dev/BacktraceTest.php               |   4 +-
 tests/php/Dev/DeprecationTest.php             | 141 ++++++-
 .../DeprecationTest/DeprecationTestObject.php |  13 +
 tests/php/Dev/DevAdminControllerTest.php      |   2 +-
 .../php/Forms/ConfirmedPasswordFieldTest.php  |  10 +-
 tests/php/Forms/CurrencyFieldDisabledTest.php |   2 +-
 tests/php/Forms/CurrencyFieldReadonlyTest.php |   4 +-
 tests/php/Forms/CurrencyFieldTest.php         |  13 +-
 tests/php/Forms/FormFieldTest.php             |   8 +-
 tests/php/Forms/FormTest.php                  |   6 +-
 tests/php/Logging/MonologErrorHandlerTest.php |   7 +-
 tests/php/ORM/ArrayListTest.php               |  15 +
 .../ORM/DataObjectSchemaGenerationTest.php    |  16 +-
 tests/php/ORM/HierarchyCachingTest.php        |   2 +-
 tests/php/ORM/HierarchyTest.php               |   2 +-
 tests/php/ORM/ManyManyListTest.php            |   4 +-
 tests/php/ORM/ManyManyThroughListTest.php     |   4 +-
 tests/php/ORM/MySQLPDOConnectorTest.php       |  13 +
 tests/php/ORM/SQLSelectTest.php               |  13 -
 tests/php/ORM/TransactionTest.php             |  16 -
 .../SessionAuthenticationHandlerTest.php      |  11 +-
 .../php/Security/MemberCsvBulkLoaderTest.php  |   4 +-
 tests/php/Security/MemberTest.php             |  14 +-
 tests/php/Security/RandomGeneratorTest.php    |   4 +
 tests/php/View/ArrayDataTest.php              |   6 -
 tests/php/View/RequirementsTest.php           |   2 +-
 tests/php/View/SSViewerTest.php               |  34 +-
 ...iewerTestIncludeScopeInheritanceInclude.ss |   2 +-
 ...stIncludeScopeInheritanceWithArgsInLoop.ss |   2 +-
 tests/php/View/ViewableDataTest.php           |   4 +
 tests/php/i18n/i18nTest.php                   |   6 +-
 tests/php/i18n/i18nTestManifest.php           |   2 +-
 tests/php/i18n/i18nTextCollectorTest.php      |   4 +-
 81 files changed, 798 insertions(+), 465 deletions(-)

diff --git a/_config.php b/_config.php
index 6cc0e44db..27dcd372a 100644
--- a/_config.php
+++ b/_config.php
@@ -1,6 +1,5 @@
 <?php
 
-use SilverStripe\Dev\Deprecation;
 use SilverStripe\View\Shortcodes\EmbedShortcodeProvider;
 use SilverStripe\View\Parsers\ShortcodeParser;
 
@@ -14,6 +13,3 @@ use SilverStripe\View\Parsers\ShortcodeParser;
 
 ShortcodeParser::get('default')
     ->register('embed', [EmbedShortcodeProvider::class, 'handle_shortcode']);
-
-// Set to 5.0.0 to show APIs marked for removal at that version
-Deprecation::notification_version('4.0.0');
diff --git a/_config/i18n.yml b/_config/i18n.yml
index a219828b8..e900f46f5 100644
--- a/_config/i18n.yml
+++ b/_config/i18n.yml
@@ -2,14 +2,14 @@
 Name: basei18n
 Before: '#defaulti18n'
 ---
-SilverStripe\i18n\Data\Sources:
+SilverStripe\Core\Manifest\ModuleManifest:
   module_priority:
     - silverstripe\admin
     - silverstripe\framework
 ---
 Name: defaulti18n
 ---
-SilverStripe\i18n\Data\Sources:
+SilverStripe\Core\Manifest\ModuleManifest:
   module_priority:
     - other_modules
 ---
diff --git a/src/Control/CookieJar.php b/src/Control/CookieJar.php
index 73467526c..6c3b0a26c 100644
--- a/src/Control/CookieJar.php
+++ b/src/Control/CookieJar.php
@@ -200,12 +200,9 @@ class CookieJar implements Cookie_Backend
 
     /**
      * Get the correct samesite value - Session cookies use a different configuration variable.
-     *
-     * @deprecated 4.12.0 The relevant methods will include a `$sameSite` parameter instead.
      */
     private function getSameSite(string $name): string
     {
-        Deprecation::notice('4.12.0', 'The relevant methods will include a `$sameSite` parameter instead.');
         if ($name === session_name()) {
             return Session::config()->get('cookie_samesite');
         }
diff --git a/src/Control/Director.php b/src/Control/Director.php
index 91023b7a7..880561253 100644
--- a/src/Control/Director.php
+++ b/src/Control/Director.php
@@ -228,7 +228,7 @@ class Director implements TemplateGlobalProvider
             ? $cookies
             : Injector::inst()->createWithArgs(Cookie_Backend::class, [$cookies ?: []]);
         $newVars['_COOKIE'] = $cookieJar->getAll(false);
-        Cookie::config()->update('report_errors', false);
+        Cookie::config()->set('report_errors', false);
         Injector::inst()->registerService($cookieJar, Cookie_Backend::class);
 
         // Backup requirements
diff --git a/src/Control/Email/Email.php b/src/Control/Email/Email.php
index 0cb60a8ac..766bf8f7c 100644
--- a/src/Control/Email/Email.php
+++ b/src/Control/Email/Email.php
@@ -268,7 +268,9 @@ class Email extends ViewableData
             $message = new Swift_Message(null, null, 'text/html', 'utf-8');
             // Set priority to fix PHP 8.1 SimpleMessage::getPriority() sscanf() null parameter
             $message->setPriority(Swift_Mime_SimpleMessage::PRIORITY_NORMAL);
-            $this->setSwiftMessage($message);
+            Deprecation::withNoReplacement(function () use ($message) {
+                $this->setSwiftMessage($message);
+            });
         }
 
         return $this->swiftMessage;
@@ -328,7 +330,9 @@ class Email extends ViewableData
      */
     public function getFrom()
     {
-        return $this->getSwiftMessage()->getFrom();
+        return Deprecation::withNoReplacement(function () {
+            return $this->getSwiftMessage()->getFrom();
+        });
     }
 
     /**
@@ -351,8 +355,9 @@ class Email extends ViewableData
     public function setFrom($address, $name = null)
     {
         $address = $this->sanitiseAddress($address);
-        $this->getSwiftMessage()->setFrom($address, $name);
-
+        Deprecation::withNoReplacement(function () use ($address, $name) {
+            $this->getSwiftMessage()->setFrom($address, $name);
+        });
         return $this;
     }
 
@@ -364,8 +369,9 @@ class Email extends ViewableData
     public function addFrom($address, $name = null)
     {
         $address = $this->sanitiseAddress($address);
-        $this->getSwiftMessage()->addFrom($address, $name);
-
+        Deprecation::withNoReplacement(function () use ($address, $name) {
+            $this->getSwiftMessage()->addFrom($address, $name);
+        });
         return $this;
     }
 
@@ -374,7 +380,9 @@ class Email extends ViewableData
      */
     public function getSender()
     {
-        return $this->getSwiftMessage()->getSender();
+        return Deprecation::withNoReplacement(function () {
+            return $this->getSwiftMessage()->getSender();
+        });
     }
 
     /**
@@ -385,8 +393,9 @@ class Email extends ViewableData
     public function setSender($address, $name = null)
     {
         $address = $this->sanitiseAddress($address);
-        $this->getSwiftMessage()->setSender($address, $name);
-
+        Deprecation::withNoReplacement(function () use ($address, $name) {
+            $this->getSwiftMessage()->setSender($address, $name);
+        });
         return $this;
     }
 
@@ -395,7 +404,9 @@ class Email extends ViewableData
      */
     public function getReturnPath()
     {
-        return $this->getSwiftMessage()->getReturnPath();
+        return Deprecation::withNoReplacement(function () {
+            return $this->getSwiftMessage()->getReturnPath();
+        });
     }
 
     /**
@@ -407,7 +418,9 @@ class Email extends ViewableData
     public function setReturnPath($address)
     {
         $address = $this->sanitiseAddress($address);
-        $this->getSwiftMessage()->setReturnPath($address);
+        Deprecation::withNoReplacement(function () use ($address) {
+            $this->getSwiftMessage()->setReturnPath($address);
+        });
         return $this;
     }
 
@@ -416,7 +429,9 @@ class Email extends ViewableData
      */
     public function getTo()
     {
-        return $this->getSwiftMessage()->getTo();
+        return Deprecation::withNoReplacement(function () {
+            return $this->getSwiftMessage()->getTo();
+        });
     }
 
     /**
@@ -432,8 +447,9 @@ class Email extends ViewableData
     public function setTo($address, $name = null)
     {
         $address = $this->sanitiseAddress($address);
-        $this->getSwiftMessage()->setTo($address, $name);
-
+        Deprecation::withNoReplacement(function () use ($address, $name) {
+            $this->getSwiftMessage()->setTo($address, $name);
+        });
         return $this;
     }
 
@@ -445,8 +461,9 @@ class Email extends ViewableData
     public function addTo($address, $name = null)
     {
         $address = $this->sanitiseAddress($address);
-        $this->getSwiftMessage()->addTo($address, $name);
-
+        Deprecation::withNoReplacement(function () use ($address, $name) {
+            $this->getSwiftMessage()->addTo($address, $name);
+        });
         return $this;
     }
 
@@ -455,7 +472,9 @@ class Email extends ViewableData
      */
     public function getCC()
     {
-        return $this->getSwiftMessage()->getCc();
+        return Deprecation::withNoReplacement(function () {
+            return $this->getSwiftMessage()->getCc();
+        });
     }
 
     /**
@@ -466,8 +485,9 @@ class Email extends ViewableData
     public function setCC($address, $name = null)
     {
         $address = $this->sanitiseAddress($address);
-        $this->getSwiftMessage()->setCc($address, $name);
-
+        Deprecation::withNoReplacement(function () use ($address, $name) {
+            $this->getSwiftMessage()->setCc($address, $name);
+        });
         return $this;
     }
 
@@ -479,8 +499,9 @@ class Email extends ViewableData
     public function addCC($address, $name = null)
     {
         $address = $this->sanitiseAddress($address);
-        $this->getSwiftMessage()->addCc($address, $name);
-
+        Deprecation::withNoReplacement(function () use ($address, $name) {
+            $this->getSwiftMessage()->addCc($address, $name);
+        });
         return $this;
     }
 
@@ -489,7 +510,9 @@ class Email extends ViewableData
      */
     public function getBCC()
     {
-        return $this->getSwiftMessage()->getBcc();
+        return Deprecation::withNoReplacement(function () {
+            return $this->getSwiftMessage()->getBcc();
+        });
     }
 
     /**
@@ -500,8 +523,9 @@ class Email extends ViewableData
     public function setBCC($address, $name = null)
     {
         $address = $this->sanitiseAddress($address);
-        $this->getSwiftMessage()->setBcc($address, $name);
-
+        Deprecation::withNoReplacement(function () use ($address, $name) {
+            $this->getSwiftMessage()->setBcc($address, $name);
+        });
         return $this;
     }
 
@@ -513,8 +537,9 @@ class Email extends ViewableData
     public function addBCC($address, $name = null)
     {
         $address = $this->sanitiseAddress($address);
-        $this->getSwiftMessage()->addBcc($address, $name);
-
+        Deprecation::withNoReplacement(function () use ($address, $name) {
+            $this->getSwiftMessage()->addBcc($address, $name);
+        });
         return $this;
     }
 
@@ -523,7 +548,9 @@ class Email extends ViewableData
      */
     public function getReplyTo()
     {
-        return $this->getSwiftMessage()->getReplyTo();
+        return Deprecation::withNoReplacement(function () {
+            return $this->getSwiftMessage()->getReplyTo();
+        });
     }
 
     /**
@@ -534,8 +561,9 @@ class Email extends ViewableData
     public function setReplyTo($address, $name = null)
     {
         $address = $this->sanitiseAddress($address);
-        $this->getSwiftMessage()->setReplyTo($address, $name);
-
+        Deprecation::withNoReplacement(function () use ($address, $name) {
+            $this->getSwiftMessage()->setReplyTo($address, $name);
+        });
         return $this;
     }
 
@@ -547,8 +575,9 @@ class Email extends ViewableData
     public function addReplyTo($address, $name = null)
     {
         $address = $this->sanitiseAddress($address);
-        $this->getSwiftMessage()->addReplyTo($address, $name);
-
+        Deprecation::withNoReplacement(function () use ($address, $name) {
+            $this->getSwiftMessage()->addReplyTo($address, $name);
+        });
         return $this;
     }
 
@@ -557,7 +586,9 @@ class Email extends ViewableData
      */
     public function getSubject()
     {
-        return $this->getSwiftMessage()->getSubject();
+        return Deprecation::withNoReplacement(function () {
+            return $this->getSwiftMessage()->getSubject();
+        });
     }
 
     /**
@@ -566,8 +597,9 @@ class Email extends ViewableData
      */
     public function setSubject($subject)
     {
-        $this->getSwiftMessage()->setSubject($subject);
-
+        Deprecation::withNoReplacement(function () use ($subject) {
+            $this->getSwiftMessage()->setSubject($subject);
+        });
         return $this;
     }
 
@@ -576,7 +608,9 @@ class Email extends ViewableData
      */
     public function getPriority()
     {
-        return $this->getSwiftMessage()->getPriority();
+        return Deprecation::withNoReplacement(function () {
+            return $this->getSwiftMessage()->getPriority();
+        });
     }
 
     /**
@@ -585,8 +619,9 @@ class Email extends ViewableData
      */
     public function setPriority($priority)
     {
-        $this->getSwiftMessage()->setPriority($priority);
-
+        Deprecation::withNoReplacement(function () use ($priority) {
+            $this->getSwiftMessage()->setPriority($priority);
+        });
         return $this;
     }
 
@@ -622,8 +657,9 @@ class Email extends ViewableData
         if ($mime) {
             $attachment->setContentType($mime);
         }
-        $this->getSwiftMessage()->attach($attachment);
-
+        Deprecation::withNoReplacement(function () use ($attachment) {
+            $this->getSwiftMessage()->attach($attachment);
+        });
         return $this;
     }
 
@@ -642,8 +678,9 @@ class Email extends ViewableData
     public function setData($data)
     {
         $this->data = $data;
-        $this->invalidateBody();
-
+        Deprecation::withNoReplacement(function () {
+            $this->invalidateBody();
+        });
         return $this;
     }
 
@@ -661,9 +698,9 @@ class Email extends ViewableData
         } else {
             $this->data->$name = $value;
         }
-
-        $this->invalidateBody();
-
+        Deprecation::withNoReplacement(function () {
+            $this->invalidateBody();
+        });
         return $this;
     }
 
@@ -680,9 +717,9 @@ class Email extends ViewableData
         } else {
             $this->data->$name = null;
         }
-
-        $this->invalidateBody();
-
+        Deprecation::withNoReplacement(function () {
+            $this->invalidateBody();
+        });
         return $this;
     }
 
@@ -691,7 +728,9 @@ class Email extends ViewableData
      */
     public function getBody()
     {
-        return $this->getSwiftMessage()->getBody();
+        return Deprecation::withNoReplacement(function () {
+            return $this->getSwiftMessage()->getBody();
+        });
     }
 
     /**
@@ -700,15 +739,16 @@ class Email extends ViewableData
      */
     public function setBody($body)
     {
-        $plainPart = $this->findPlainPart();
-        if ($plainPart) {
-            $this->getSwiftMessage()->detach($plainPart);
-        }
-        unset($plainPart);
-
-        $body = HTTP::absoluteURLs($body);
-        $this->getSwiftMessage()->setBody($body);
-
+        Deprecation::withNoReplacement(function () use ($body) {
+            $plainPart = $this->findPlainPart();
+            if ($plainPart) {
+                $this->getSwiftMessage()->detach($plainPart);
+            }
+            unset($plainPart);
+    
+            $body = HTTP::absoluteURLs($body);
+            $this->getSwiftMessage()->setBody($body);
+        });
         return $this;
     }
 
@@ -746,10 +786,11 @@ class Email extends ViewableData
     public function debug()
     {
         Deprecation::notice('4.12.0', 'Will be removed without equivalent functionality to replace it');
-        $this->render();
-
-        $class = static::class;
-        return "<h2>Email template {$class}:</h2>\n" . '<pre>' . $this->getSwiftMessage()->toString() . '</pre>';
+        return Deprecation::withNoReplacement(function () {
+            $this->render();
+            $class = static::class;
+            return "<h2>Email template {$class}:</h2>\n" . '<pre>' . $this->getSwiftMessage()->toString() . '</pre>';
+        });
     }
 
     /**
@@ -854,13 +895,15 @@ class Email extends ViewableData
      */
     public function send()
     {
-        if (!$this->getBody()) {
-            $this->render();
-        }
-        if (!$this->hasPlainPart()) {
-            $this->generatePlainPartFromBody();
-        }
-        return Injector::inst()->get(Mailer::class)->send($this);
+        return Deprecation::withNoReplacement(function () {
+            if (!$this->getBody()) {
+                $this->render();
+            }
+            if (!$this->hasPlainPart()) {
+                $this->generatePlainPartFromBody();
+            }
+            return Injector::inst()->get(Mailer::class)->send($this);
+        });
     }
 
     /**
@@ -868,10 +911,12 @@ class Email extends ViewableData
      */
     public function sendPlain()
     {
-        if (!$this->hasPlainPart()) {
-            $this->render(true);
-        }
-        return Injector::inst()->get(Mailer::class)->send($this);
+        return Deprecation::withNoReplacement(function () {
+            if (!$this->hasPlainPart()) {
+                $this->render(true);
+            }
+            return Injector::inst()->get(Mailer::class)->send($this);
+        });
     }
 
     /**
@@ -884,68 +929,71 @@ class Email extends ViewableData
     public function render($plainOnly = false)
     {
         Deprecation::notice('4.12.0', 'Will be removed without equivalent functionality to replace it');
-
-        if ($existingPlainPart = $this->findPlainPart()) {
-            $this->getSwiftMessage()->detach($existingPlainPart);
-        }
-        unset($existingPlainPart);
-
-        // Respect explicitly set body
-        $htmlPart = $plainOnly ? null : $this->getBody();
-        $plainPart = $plainOnly ? $this->getBody() : null;
-
-        // Ensure we can at least render something
-        $htmlTemplate = $this->getHTMLTemplate();
-        $plainTemplate = $this->getPlainTemplate();
-        if (!$htmlTemplate && !$plainTemplate && !$plainPart && !$htmlPart) {
-            return $this;
-        }
-
-        // Do not interfere with emails styles
-        Requirements::clear();
-
-        // Render plain part
-        if ($plainTemplate && !$plainPart) {
-            $plainPart = $this->renderWith($plainTemplate, $this->getData())->Plain();
-        }
-
-        // Render HTML part, either if sending html email, or a plain part is lacking
-        if (!$htmlPart && $htmlTemplate && (!$plainOnly || empty($plainPart))) {
-            $htmlPart = $this->renderWith($htmlTemplate, $this->getData());
-        }
-
-        // Plain part fails over to generated from html
-        if (!$plainPart && $htmlPart) {
-            /** @var DBHTMLText $htmlPartObject */
-            $htmlPartObject = DBField::create_field('HTMLFragment', $htmlPart);
-            $plainPart = $htmlPartObject->Plain();
-        }
-
-        // Rendering is finished
-        Requirements::restore();
-
-        // Fail if no email to send
-        if (!$plainPart && !$htmlPart) {
-            return $this;
-        }
-
-        // Build HTML / Plain components
-        if ($htmlPart && !$plainOnly) {
-            $this->setBody($htmlPart);
-            $this->getSwiftMessage()->setContentType('text/html');
-            $this->getSwiftMessage()->setCharset('utf-8');
-            if ($plainPart) {
-                $this->getSwiftMessage()->addPart($plainPart, 'text/plain', 'utf-8');
+        return Deprecation::withNoReplacement(function () use ($plainOnly) {
+            $existingPlainPart = Deprecation::withNoReplacement(function () {
+                return $this->findPlainPart();
+            });
+            if ($existingPlainPart) {
+                $this->getSwiftMessage()->detach($existingPlainPart);
             }
-        } else {
-            if ($plainPart) {
-                $this->setBody($plainPart);
-            }
-            $this->getSwiftMessage()->setContentType('text/plain');
-            $this->getSwiftMessage()->setCharset('utf-8');
-        }
+            unset($existingPlainPart);
 
-        return $this;
+            // Respect explicitly set body
+            $htmlPart = $plainOnly ? null : $this->getBody();
+            $plainPart = $plainOnly ? $this->getBody() : null;
+
+            // Ensure we can at least render something
+            $htmlTemplate = $this->getHTMLTemplate();
+            $plainTemplate = $this->getPlainTemplate();
+            if (!$htmlTemplate && !$plainTemplate && !$plainPart && !$htmlPart) {
+                return $this;
+            }
+
+            // Do not interfere with emails styles
+            Requirements::clear();
+
+            // Render plain part
+            if ($plainTemplate && !$plainPart) {
+                $plainPart = $this->renderWith($plainTemplate, $this->getData())->Plain();
+            }
+
+            // Render HTML part, either if sending html email, or a plain part is lacking
+            if (!$htmlPart && $htmlTemplate && (!$plainOnly || empty($plainPart))) {
+                $htmlPart = $this->renderWith($htmlTemplate, $this->getData());
+            }
+
+            // Plain part fails over to generated from html
+            if (!$plainPart && $htmlPart) {
+                /** @var DBHTMLText $htmlPartObject */
+                $htmlPartObject = DBField::create_field('HTMLFragment', $htmlPart);
+                $plainPart = $htmlPartObject->Plain();
+            }
+
+            // Rendering is finished
+            Requirements::restore();
+
+            // Fail if no email to send
+            if (!$plainPart && !$htmlPart) {
+                return $this;
+            }
+
+            // Build HTML / Plain components
+            if ($htmlPart && !$plainOnly) {
+                $this->setBody($htmlPart);
+                $this->getSwiftMessage()->setContentType('text/html');
+                $this->getSwiftMessage()->setCharset('utf-8');
+                if ($plainPart) {
+                    $this->getSwiftMessage()->addPart($plainPart, 'text/plain', 'utf-8');
+                }
+            } else {
+                if ($plainPart) {
+                    $this->setBody($plainPart);
+                }
+                $this->getSwiftMessage()->setContentType('text/plain');
+                $this->getSwiftMessage()->setCharset('utf-8');
+            }
+            return $this;
+        });
     }
 
     /**
@@ -956,12 +1004,14 @@ class Email extends ViewableData
     public function findPlainPart()
     {
         Deprecation::notice('4.12.0', 'Will be removed without equivalent functionality to replace it');
-        foreach ($this->getSwiftMessage()->getChildren() as $child) {
-            if ($child instanceof Swift_MimePart && $child->getContentType() == 'text/plain') {
-                return $child;
+        return Deprecation::withNoReplacement(function () {
+            foreach ($this->getSwiftMessage()->getChildren() as $child) {
+                if ($child instanceof Swift_MimePart && $child->getContentType() == 'text/plain') {
+                    return $child;
+                }
             }
-        }
-        return false;
+            return false;
+        });
     }
 
     /**
@@ -972,10 +1022,12 @@ class Email extends ViewableData
     public function hasPlainPart()
     {
         Deprecation::notice('4.12.0', 'Will be removed without equivalent functionality to replace it');
-        if ($this->getSwiftMessage()->getContentType() === 'text/plain') {
-            return true;
-        }
-        return (bool) $this->findPlainPart();
+        return Deprecation::withNoReplacement(function () {
+            if ($this->getSwiftMessage()->getContentType() === 'text/plain') {
+                return true;
+            }
+            return (bool) $this->findPlainPart();
+        });
     }
 
     /**
@@ -988,18 +1040,19 @@ class Email extends ViewableData
     public function generatePlainPartFromBody()
     {
         Deprecation::notice('4.12.0', 'Will be removed without equivalent functionality to replace it');
-        $plainPart = $this->findPlainPart();
-        if ($plainPart) {
-            $this->getSwiftMessage()->detach($plainPart);
-        }
-        unset($plainPart);
+        return Deprecation::withNoReplacement(function () {
+            $plainPart = $this->findPlainPart();
+            if ($plainPart) {
+                $this->getSwiftMessage()->detach($plainPart);
+            }
+            unset($plainPart);
 
-        $this->getSwiftMessage()->addPart(
-            Convert::xml2raw($this->getBody()),
-            'text/plain',
-            'utf-8'
-        );
-
-        return $this;
+            $this->getSwiftMessage()->addPart(
+                Convert::xml2raw($this->getBody()),
+                'text/plain',
+                'utf-8'
+            );
+            return $this;
+        });
     }
 }
diff --git a/src/Control/Email/SwiftMailer.php b/src/Control/Email/SwiftMailer.php
index 33371acdc..3afca409b 100644
--- a/src/Control/Email/SwiftMailer.php
+++ b/src/Control/Email/SwiftMailer.php
@@ -40,7 +40,9 @@ class SwiftMailer implements Mailer
      */
     public function __construct()
     {
-        Deprecation::notice('4.12.0', 'Will be replaced with symfony/mailer', Deprecation::SCOPE_CLASS);
+        Deprecation::withNoReplacement(function () {
+            Deprecation::notice('4.12.0', 'Will be replaced with symfony/mailer', Deprecation::SCOPE_CLASS);
+        });
     }
 
     public function send($message)
diff --git a/src/Control/Email/SwiftPlugin.php b/src/Control/Email/SwiftPlugin.php
index 277c4f18b..5e53e8a3e 100644
--- a/src/Control/Email/SwiftPlugin.php
+++ b/src/Control/Email/SwiftPlugin.php
@@ -11,7 +11,9 @@ class SwiftPlugin implements \Swift_Events_SendListener
 {
     public function __construct()
     {
-        Deprecation::notice('4.12.0', 'Will be replaced with symfony/mailer', Deprecation::SCOPE_CLASS);
+        Deprecation::withNoReplacement(function () {
+            Deprecation::notice('4.12.0', 'Will be replaced with symfony/mailer', Deprecation::SCOPE_CLASS);
+        });
     }
 
     /**
diff --git a/src/Control/HTTP.php b/src/Control/HTTP.php
index 84fce924d..cce77aec4 100644
--- a/src/Control/HTTP.php
+++ b/src/Control/HTTP.php
@@ -126,7 +126,7 @@ class HTTP
             if (preg_match('/^\w+:/', $url ?? '')) {
                 return $url;
             }
-            return Director::absoluteURL($url, true);
+            return Director::absoluteURL($url);
         });
     }
 
@@ -474,6 +474,8 @@ class HTTP
      * Ensure that all deprecated HTTP cache settings are respected
      *
      * @deprecated 4.2.0 Use HTTPCacheControlMiddleware instead
+     * Simply delete this method in CMS 5 and the calls to it from HTTPCacheControlMiddleware
+     *
      * @throws \LogicException
      * @param HTTPRequest $request
      * @param HTTPResponse $response
@@ -491,32 +493,32 @@ class HTTP
 
         // if http caching is disabled by config, disable it - used on dev environments due to frequently changing
         // templates and other data. will be overridden by forced publicCache(true) or privateCache(true) calls
-        if ($config->get('disable_http_cache')) {
-            Deprecation::notice('5.0', 'Use HTTPCacheControlMiddleware.defaultState/.defaultForcingLevel instead');
-            $cacheControlMiddleware->disableCache();
-        }
+        Deprecation::withNoReplacement(function () use ($config, $cacheControlMiddleware) {
+            if ($config->get('disable_http_cache')) {
+                $cacheControlMiddleware->disableCache();
+            }
+        });
 
         // if no caching ajax requests, disable ajax if is ajax request
-        if (!$config->get('cache_ajax_requests') && Director::is_ajax()) {
-            Deprecation::notice(
-                '5.0',
-                'HTTP.cache_ajax_requests config is deprecated. Use HTTPCacheControlMiddleware::disableCache() instead'
-            );
-            $cacheControlMiddleware->disableCache();
-        }
+        Deprecation::withNoReplacement(function () use ($config, $cacheControlMiddleware) {
+            if (!$config->get('cache_ajax_requests') && Director::is_ajax()) {
+                $cacheControlMiddleware->disableCache();
+            }
+        });
 
         // Pass vary to middleware
-        $configVary = $config->get('vary');
+        $configVary = Deprecation::withNoReplacement(function () use ($config) {
+            return $config->get('vary');
+        });
         if ($configVary) {
-            Deprecation::notice('5.0', 'Use HTTPCacheControlMiddleware.defaultVary instead');
             $cacheControlMiddleware->addVary($configVary);
         }
 
         // Pass cache_control to middleware
-        $configCacheControl = $config->get('cache_control');
+        $configCacheControl = Deprecation::withNoReplacement(function () use ($config) {
+            return $config->get('cache_control');
+        });
         if ($configCacheControl) {
-            Deprecation::notice('5.0', 'Use HTTPCacheControlMiddleware API instead');
-
             $supportedDirectives = ['max-age', 'no-cache', 'no-store', 'must-revalidate'];
             if ($foundUnsupported = array_diff(array_keys($configCacheControl ?? []), $supportedDirectives)) {
                 throw new \LogicException(
diff --git a/src/Control/Middleware/FlushMiddleware.php b/src/Control/Middleware/FlushMiddleware.php
index e3bd61fbe..98b49423b 100644
--- a/src/Control/Middleware/FlushMiddleware.php
+++ b/src/Control/Middleware/FlushMiddleware.php
@@ -2,10 +2,12 @@
 
 namespace SilverStripe\Control\Middleware;
 
-use SilverStripe\Control\Director;
 use SilverStripe\Control\HTTPRequest;
+use SilverStripe\Core\BaseKernel;
 use SilverStripe\Core\ClassInfo;
 use SilverStripe\Core\Flushable;
+use SilverStripe\Core\Injector\Injector;
+use SilverStripe\Core\Kernel;
 
 /**
  * Triggers a call to flush() on all implementors of Flushable.
@@ -14,7 +16,9 @@ class FlushMiddleware implements HTTPMiddleware
 {
     public function process(HTTPRequest $request, callable $delegate)
     {
-        if (Director::isManifestFlushed()) {
+        /** @var BaseKernel $kernel */
+        $kernel = Injector::inst()->get(Kernel::class);
+        if ((method_exists($kernel, 'isFlushed') && $kernel->isFlushed())) {
             // Disable cache when flushing
             HTTPCacheControlMiddleware::singleton()->disableCache(true);
 
diff --git a/src/Control/Middleware/HTTPCacheControlMiddleware.php b/src/Control/Middleware/HTTPCacheControlMiddleware.php
index 4f7aa49c6..1a64b4b54 100644
--- a/src/Control/Middleware/HTTPCacheControlMiddleware.php
+++ b/src/Control/Middleware/HTTPCacheControlMiddleware.php
@@ -12,6 +12,7 @@ use SilverStripe\Core\Injector\Injectable;
 use SilverStripe\Core\Injector\Injector;
 use SilverStripe\Core\Resettable;
 use SilverStripe\ORM\FieldType\DBDatetime;
+use SilverStripe\Dev\Deprecation;
 
 class HTTPCacheControlMiddleware implements HTTPMiddleware, Resettable
 {
@@ -51,7 +52,9 @@ class HTTPCacheControlMiddleware implements HTTPMiddleware, Resettable
         $this->augmentState($request, $response);
 
         // Update state based on deprecated HTTP settings
-        HTTP::augmentState($request, $response);
+        Deprecation::withNoReplacement(function () use ($request, $response) {
+            HTTP::augmentState($request, $response);
+        });
 
         // Add all headers to this response object
         $this->applyToResponse($response);
diff --git a/src/Control/Middleware/URLSpecialsMiddleware/FlushScheduler.php b/src/Control/Middleware/URLSpecialsMiddleware/FlushScheduler.php
index 6f189286e..f2b62d0c2 100644
--- a/src/Control/Middleware/URLSpecialsMiddleware/FlushScheduler.php
+++ b/src/Control/Middleware/URLSpecialsMiddleware/FlushScheduler.php
@@ -2,10 +2,10 @@
 
 namespace SilverStripe\Control\Middleware\URLSpecialsMiddleware;
 
+use SilverStripe\Core\BaseKernel;
 use SilverStripe\Core\Kernel;
 use SilverStripe\Core\Injector\Injector;
 use SilverStripe\Core\Startup\ScheduledFlushDiscoverer;
-use SilverStripe\Control\Director;
 use SilverStripe\Control\HTTPRequest;
 
 /**
@@ -30,11 +30,12 @@ trait FlushScheduler
     {
         $flush = array_key_exists('flush', $request->getVars() ?? []) || ($request->getURL() === 'dev/build');
 
-        if (!$flush || Director::isManifestFlushed()) {
+        /** @var BaseKernel $kernel */
+        $kernel = Injector::inst()->get(Kernel::class);
+        if (!$flush || (method_exists($kernel, 'isFlushed') && $kernel->isFlushed())) {
             return false;
         }
 
-        $kernel = Injector::inst()->get(Kernel::class);
         ScheduledFlushDiscoverer::scheduleFlush($kernel);
 
         return true;
diff --git a/src/Control/RSS/RSSFeed.php b/src/Control/RSS/RSSFeed.php
index fd35b617e..5ab5eae9b 100644
--- a/src/Control/RSS/RSSFeed.php
+++ b/src/Control/RSS/RSSFeed.php
@@ -222,7 +222,7 @@ class RSSFeed extends ViewableData
     public function outputToBrowser()
     {
         $prevState = SSViewer::config()->uninherited('source_file_comments');
-        SSViewer::config()->update('source_file_comments', false);
+        SSViewer::config()->set('source_file_comments', false);
 
         $response = Controller::curr()->getResponse();
 
@@ -236,7 +236,7 @@ class RSSFeed extends ViewableData
 
         $response->addHeader("Content-Type", "application/rss+xml; charset=utf-8");
 
-        SSViewer::config()->update('source_file_comments', $prevState);
+        SSViewer::config()->set('source_file_comments', $prevState);
         return $this->renderWith($this->getTemplates());
     }
 
diff --git a/src/Control/RequestProcessor.php b/src/Control/RequestProcessor.php
index 0661fcdda..f8ef07623 100644
--- a/src/Control/RequestProcessor.php
+++ b/src/Control/RequestProcessor.php
@@ -29,7 +29,9 @@ class RequestProcessor implements HTTPMiddleware
      */
     public function __construct($filters = [])
     {
-        Deprecation::notice('4.0.1', 'Use HTTPMiddleware directly instead.', Deprecation::SCOPE_CLASS);
+        Deprecation::withNoReplacement(function () {
+            Deprecation::notice('4.0.1', 'Use HTTPMiddleware directly instead.', Deprecation::SCOPE_CLASS);
+        });
         $this->filters = $filters;
     }
 
diff --git a/src/Control/Session.php b/src/Control/Session.php
index 01623d87f..5d49b92b3 100644
--- a/src/Control/Session.php
+++ b/src/Control/Session.php
@@ -586,13 +586,11 @@ class Session
      * Recursively apply the changes represented in $data to $dest.
      * Used to update $_SESSION
      *
-     * @deprecated 4.1.0 Use recursivelyApplyChanges() instead
      * @param array $data
      * @param array $dest
      */
     protected function recursivelyApply($data, &$dest)
     {
-        Deprecation::notice('4.1.0', 'Use recursivelyApplyChanges() instead');
         foreach ($data as $k => $v) {
             if (is_array($v)) {
                 if (!isset($dest[$k]) || !is_array($dest[$k])) {
diff --git a/src/Control/SimpleResourceURLGenerator.php b/src/Control/SimpleResourceURLGenerator.php
index e6ea62175..40bd6189d 100644
--- a/src/Control/SimpleResourceURLGenerator.php
+++ b/src/Control/SimpleResourceURLGenerator.php
@@ -82,7 +82,10 @@ class SimpleResourceURLGenerator implements ResourceURLGenerator
             // Determine lookup mechanism based on existence of public/ folder.
             // From 5.0 onwards only resolvePublicResource() will be used.
             if (!Director::publicDir()) {
-                list($exists, $absolutePath, $relativePath) = $this->resolveUnsecuredResource($relativePath);
+                $ret = Deprecation::withNoReplacement(function () use ($relativePath) {
+                    return $this->resolveUnsecuredResource($relativePath);
+                });
+                list($exists, $absolutePath, $relativePath) = $ret;
             } else {
                 list($exists, $absolutePath, $relativePath) = $this->resolvePublicResource($relativePath);
             }
diff --git a/src/Core/BaseKernel.php b/src/Core/BaseKernel.php
index ee3370d54..3706f94d6 100644
--- a/src/Core/BaseKernel.php
+++ b/src/Core/BaseKernel.php
@@ -180,18 +180,24 @@ abstract class BaseKernel implements Kernel
     protected function bootManifests($flush)
     {
         // Setup autoloader
-        $this->getClassLoader()->init(
-            $this->getIncludeTests(),
-            $flush,
-            $this->getIgnoredCIConfigs()
-        );
+        $ignoredCIConfigs = Deprecation::withNoReplacement(function () {
+            return $this->getIgnoredCIConfigs();
+        });
 
-        // Find modules
-        $this->getModuleLoader()->init(
-            $this->getIncludeTests(),
-            $flush,
-            $this->getIgnoredCIConfigs()
-        );
+        Deprecation::withNoReplacement(function () use ($flush, $ignoredCIConfigs) {
+            $this->getClassLoader()->init(
+                $this->getIncludeTests(),
+                $flush,
+                $ignoredCIConfigs
+            );
+
+            // Find modules
+            $this->getModuleLoader()->init(
+                $this->getIncludeTests(),
+                $flush,
+                $ignoredCIConfigs
+            );
+        });
 
         // Flush config
         if ($flush) {
@@ -209,11 +215,13 @@ abstract class BaseKernel implements Kernel
             $defaultSet->setProject(
                 ModuleManifest::config()->get('project')
             );
-            $defaultSet->init(
-                $this->getIncludeTests(),
-                $flush,
-                $this->getIgnoredCIConfigs()
-            );
+            Deprecation::withNoReplacement(function () use ($defaultSet, $flush, $ignoredCIConfigs) {
+                $defaultSet->init(
+                    $this->getIncludeTests(),
+                    $flush,
+                    $ignoredCIConfigs
+                );
+            });
         }
     }
 
@@ -259,12 +267,9 @@ abstract class BaseKernel implements Kernel
      * Get the environment type
      *
      * @return string
-     *
-     * @deprecated 4.12.0 Use Director::get_environment_type() instead
      */
     public function getEnvironment()
     {
-        Deprecation::notice('4.12.0', 'Use Director::get_environment_type() instead');
         // Check set
         if ($this->enviroment) {
             return $this->enviroment;
@@ -288,12 +293,9 @@ abstract class BaseKernel implements Kernel
      * Check or update any temporary environment specified in the session.
      *
      * @return null|string
-     *
-     * @deprecated 4.12.0 Use Director::get_session_environment_type() instead
      */
     protected function sessionEnvironment()
     {
-        Deprecation::notice('4.12.0', 'Use Director::get_session_environment_type() instead');
         if (!$this->booted) {
             // session is not initialyzed yet, neither is manifest
             return null;
diff --git a/src/Core/Convert.php b/src/Core/Convert.php
index 0fb4293c1..2021e8446 100644
--- a/src/Core/Convert.php
+++ b/src/Core/Convert.php
@@ -275,7 +275,7 @@ class Convert
     /**
      * Convert a JSON string into an array.
      *
-     * @deprecated 4.4.0 Use json_decode() instead
+     * @deprecated 4.4.0 Use json_decode($val, true) instead
      * @param string $val JSON string to convert
      * @return array|boolean
      */
diff --git a/src/Core/Manifest/ClassLoader.php b/src/Core/Manifest/ClassLoader.php
index 238fa647f..ac562dcd2 100644
--- a/src/Core/Manifest/ClassLoader.php
+++ b/src/Core/Manifest/ClassLoader.php
@@ -131,7 +131,9 @@ class ClassLoader
         foreach ($this->manifests as $manifest) {
             /** @var ClassManifest $instance */
             $instance = $manifest['instance'];
-            $instance->init($includeTests, $forceRegen, $ignoredCIConfigs);
+            Deprecation::withNoReplacement(function () use ($instance, $includeTests, $forceRegen, $ignoredCIConfigs) {
+                $instance->init($includeTests, $forceRegen, $ignoredCIConfigs);
+            });
         }
 
         $this->registerAutoloader();
diff --git a/src/Core/Manifest/ClassManifest.php b/src/Core/Manifest/ClassManifest.php
index 7ebdc0dfe..7bd407304 100644
--- a/src/Core/Manifest/ClassManifest.php
+++ b/src/Core/Manifest/ClassManifest.php
@@ -297,7 +297,9 @@ class ClassManifest
         }
 
         // Build
-        $this->regenerate($includeTests, $ignoredCIConfigs);
+        Deprecation::withNoReplacement(function () use ($includeTests, $ignoredCIConfigs) {
+            $this->regenerate($includeTests, $ignoredCIConfigs);
+        });
     }
 
     /**
diff --git a/src/Core/Manifest/ManifestFileFinder.php b/src/Core/Manifest/ManifestFileFinder.php
index 75763e4ed..9011a51e8 100644
--- a/src/Core/Manifest/ManifestFileFinder.php
+++ b/src/Core/Manifest/ManifestFileFinder.php
@@ -4,6 +4,7 @@ namespace SilverStripe\Core\Manifest;
 
 use RuntimeException;
 use SilverStripe\Assets\FileFinder;
+use SilverStripe\Dev\Deprecation;
 
 /**
  * An extension to the default file finder with some extra filters to facilitate
@@ -285,7 +286,9 @@ class ManifestFileFinder extends FileFinder
         if ($this->isDirectoryModule($newBasename, $newPathname, $newDepth)) {
             // We've reached the root of the module folder, we can read the PHP CI config now
             $module = new Module($newPathname, $this->upLevels($newPathname, $newDepth));
-            $config = $module->getCIConfig();
+            $config = Deprecation::withNoReplacement(function () use ($module) {
+                return $module->getCIConfig();
+            });
 
             if (empty($config['PHP'])) {
                 // This should never happen
diff --git a/src/Dev/Deprecation.php b/src/Dev/Deprecation.php
index 5bd17cda6..3ca6a0d3b 100644
--- a/src/Dev/Deprecation.php
+++ b/src/Dev/Deprecation.php
@@ -5,6 +5,7 @@ namespace SilverStripe\Dev;
 use BadMethodCallException;
 use SilverStripe\Control\Director;
 use SilverStripe\Core\Environment;
+use SilverStripe\Core\Injector\InjectionCreator;
 use SilverStripe\Core\Injector\InjectorLoader;
 use SilverStripe\Core\Manifest\Module;
 
@@ -21,19 +22,7 @@ use SilverStripe\Core\Manifest\Module;
  *
  * This class abstracts the above pattern and adds a way to do that.
  *
- * Each call to notice passes a version that the notice will be valid from. Additionally this class has a notion of the
- * version it should use when deciding whether to raise the notice. If that version is equal to or greater than the
- * notices version (and SilverStripe is in dev mode) a deprecation message will be raised.
- *
- * Normally the checking version will be the release version of SilverStripe, but a developer can choose to set it to a
- * future version, to see how their code will behave in future versions.
- *
- * Modules can also set the version for calls they make - either setting it to a future version in order to ensure
- * forwards compatibility or setting it backwards if a module has not yet removed references to deprecated methods.
- *
- * When set per-module, only direct calls to deprecated methods from those modules are considered - if the module
- * calls a non-module method which then calls a deprecated method, that call will use the global check version, not
- * the module specific check version.
+ * Each call to notice passes a version that the notice will be valid from.
  */
 class Deprecation
 {
@@ -58,10 +47,22 @@ class Deprecation
      * must be available before this to avoid infinite loops.
      *
      * @var boolean|null
-     * @deprecated 4.12.0 Use $is_enabled instead
+     * @deprecated 4.12.0 Use $currentlyEnabled instead
      */
     protected static $enabled = null;
 
+    /**
+     * @var array
+     * @deprecated 4.12.0 Will be removed without equivalent functionality to replace it
+     */
+    protected static $module_version_overrides = [];
+
+    /**
+     * @var array
+     * @deprecated 4.12.0 Will be removed without equivalent functionality to replace it
+     */
+    public static $notice_level = E_USER_DEPRECATED;
+
     /**
      * Must be configured outside of the config API, as deprecation API
      * must be available before this to avoid infinite loops.
@@ -70,48 +71,64 @@ class Deprecation
      *
      * @internal - Marked as internal so this and other private static's are not treated as config
      */
-    private static bool $is_enabled = false;
-
-    /**
-     * @var array
-     * @deprecated 4.12.0 Will be removed without equivalent functionality to replace it
-     */
-    protected static $module_version_overrides = [];
+    private static bool $currentlyEnabled = false;
 
     /**
      * @internal
      */
-    private static bool $inside_notice = false;
+    private static bool $insideNotice = false;
 
     /**
-     * @var array
-     * @deprecated 4.12.0 Will be removed without equivalent functionality to replace it
+     * @internal
      */
-    public static $notice_level = E_USER_DEPRECATED;
+    private static bool $insideWithNoReplacement = false;
 
     /**
-     * Buffer of user_errors to be raised when enabled() is called
-     *
-     * This is used when setting deprecated config via yaml, before Deprecation::enable() has been called in _config.php
-     * Deprecated config set via yaml will only be shown in the browser when using ?flush=1
-     * It will not show in CLI when running dev/build flush=1
+     * Buffer of user_errors to be raised
      *
      * @internal
      */
-    private static array $user_error_message_buffer = [];
+    private static array $userErrorMessageBuffer = [];
 
-    public static function enable(): void
+    /**
+     * @internal
+     */
+    private static bool $haveSetShutdownFunction = false;
+
+    /**
+     * @internal
+     */
+    private static bool $showNoReplacementNotices = false;
+
+    public static function enable(bool $showNoReplacementNotices = false): void
     {
-        static::$is_enabled = true;
-        foreach (self::$user_error_message_buffer as $message) {
-            user_error($message, E_USER_DEPRECATED);
-        }
-        self::$user_error_message_buffer = [];
+        static::$currentlyEnabled = true;
+        static::$showNoReplacementNotices = $showNoReplacementNotices;
     }
 
     public static function disable(): void
     {
-        static::$is_enabled = false;
+        static::$currentlyEnabled = false;
+    }
+
+    /**
+     * Used to wrap deprecated methods and deprecated config get()/set() that will be removed
+     * in the next major version with no replacement. This is done to surpress deprecation notices
+     * by for calls from the vendor dir to deprecated code that projects have no ability to change
+     *
+     * @return mixed
+     */
+    public static function withNoReplacement(callable $func)
+    {
+        if (self::$insideWithNoReplacement) {
+            return $func();
+        }
+        self::$insideWithNoReplacement = true;
+        try {
+            return $func();
+        } finally {
+            self::$insideWithNoReplacement = false;
+        }
     }
 
     /**
@@ -159,12 +176,19 @@ class Deprecation
         if (!$level) {
             $level = 1;
         }
-        $called = $backtrace ? $backtrace[$level] : [];
-
-        if (isset($called['class'])) {
-            return $called['class'] . $called['type'] . $called['function'];
+        $newLevel = $level;
+        // handle call_user_func
+        if ($level === 4 && strpos($backtrace[2]['function'] ?? '', 'call_user_func') !== false) {
+            $newLevel = 5;
+        } elseif (strpos($backtrace[$level]['function'] ?? '', 'call_user_func') !== false) {
+            $newLevel = $level + 1;
         }
-        return $called['function'] ?? '';
+        // handle InjectionCreator
+        if ($level == 4 && ($backtrace[$newLevel]['class'] ?? '') === InjectionCreator::class) {
+            $newLevel = $newLevel + 4;
+        }
+        $called = $backtrace[$newLevel] ?? [];
+        return ($called['class'] ?? '') . ($called['type'] ?? '') . ($called['function'] ?? '');
     }
 
     /**
@@ -179,12 +203,12 @@ class Deprecation
         // noop
     }
 
-    private static function get_is_enabled(): bool
+    public static function isEnabled(): bool
     {
         if (!Director::isDev()) {
             return false;
         }
-        return static::$is_enabled || Environment::getEnv('SS_DEPRECATION_ENABLED');
+        return static::$currentlyEnabled || Environment::getEnv('SS_DEPRECATION_ENABLED');
     }
 
     /**
@@ -199,6 +223,24 @@ class Deprecation
         // noop
     }
 
+    public static function outputNotices(): void
+    {
+        if (!self::isEnabled()) {
+            return;
+        }
+        // using a while loop with array_shift() to ensure that self::$userErrorMessageBuffer will have
+        // have values removed from it before calling user_error()
+        while (count(self::$userErrorMessageBuffer)) {
+            $arr = array_shift(self::$userErrorMessageBuffer);
+            $message = $arr['message'];
+            $calledInsideWithNoReplacement = $arr['calledInsideWithNoReplacement'];
+            if ($calledInsideWithNoReplacement && !self::$showNoReplacementNotices) {
+                continue;
+            }
+            user_error($message, E_USER_DEPRECATED);
+        }
+    }
+
     /**
      * Raise a notice indicating the method is deprecated if the version passed as the second argument is greater
      * than or equal to the check version set via ::notification_version
@@ -209,22 +251,23 @@ class Deprecation
      */
     public static function notice($atVersion, $string = '', $scope = Deprecation::SCOPE_METHOD)
     {
-        if (static::$inside_notice) {
+        if (static::$insideNotice) {
             return;
         }
-        static::$inside_notice = true;
+        static::$insideNotice = true;
         // try block needs to wrap all code in case anything inside the try block
         // calls something else that calls Deprecation::notice()
         try {
             if ($scope === self::SCOPE_CONFIG) {
-                if (self::get_is_enabled()) {
-                    user_error($string, E_USER_DEPRECATED);
-                } else {
-                    self::$user_error_message_buffer[] = $string;
-                }
+                // Deprecated config set via yaml will only be shown in the browser when using ?flush=1
+                // It will not show in CLI when running dev/build flush=1
+                self::$userErrorMessageBuffer[] = [
+                    'message' => $string,
+                    'calledInsideWithNoReplacement' => self::$insideWithNoReplacement
+                ];
             } else {
-                if (!self::get_is_enabled()) {
-                    // Do not add to self::$user_error_message_buffer, as the backtrace is too expensive
+                if (!self::isEnabled()) {
+                    // Do not add to self::$userErrorMessageBuffer, as the backtrace is too expensive
                     return;
                 }
     
@@ -234,7 +277,7 @@ class Deprecation
                 // Get the calling scope
                 if ($scope == Deprecation::SCOPE_METHOD) {
                     $backtrace = debug_backtrace(0);
-                    $caller = self::get_called_method_from_trace($backtrace);
+                    $caller = self::get_called_method_from_trace($backtrace, 1);
                 } elseif ($scope == Deprecation::SCOPE_CLASS) {
                     $backtrace = debug_backtrace(0);
                     $caller = isset($backtrace[1]['class']) ? $backtrace[1]['class'] : '(unknown)';
@@ -242,18 +285,30 @@ class Deprecation
                     $caller = false;
                 }
     
-                // Then raise the notice
                 if (substr($string, -1) != '.') {
                     $string .= ".";
                 }
 
-                $string .= " Called from " . self::get_called_method_from_trace($backtrace, 2) . '.';
+                $level = self::$insideWithNoReplacement ? 4 : 2;
+                $string .= " Called from " . self::get_called_method_from_trace($backtrace, $level) . '.';
 
                 if ($caller) {
-                    user_error($caller . ' is deprecated.' . ($string ? ' ' . $string : ''), E_USER_DEPRECATED);
-                } else {
-                    user_error($string, E_USER_DEPRECATED);
+                    $string = $caller . ' is deprecated.' . ($string ? ' ' . $string : '');
                 }
+                self::$userErrorMessageBuffer[] = [
+                    'message' => $string,
+                    'calledInsideWithNoReplacement' => self::$insideWithNoReplacement
+                ];
+            }
+            if (!self::$haveSetShutdownFunction && self::isEnabled()) {
+                // Use a shutdown function rather than immediately calling user_error() so that notices
+                // do not interfere with setting session varibles i.e. headers already sent error
+                // it also means the deprecation notices appear below all phpunit output in CI
+                // which is far nicer than having it spliced between phpunit output
+                register_shutdown_function(function () {
+                    self::outputNotices();
+                });
+                self::$haveSetShutdownFunction = true;
             }
         } catch (BadMethodCallException $e) {
             if ($e->getMessage() === InjectorLoader::NO_MANIFESTS_AVAILABLE) {
@@ -264,7 +319,7 @@ class Deprecation
                 throw $e;
             }
         } finally {
-            static::$inside_notice = false;
+            static::$insideNotice = false;
         }
     }
 
diff --git a/src/Dev/FunctionalTest.php b/src/Dev/FunctionalTest.php
index c0329c355..97025c291 100644
--- a/src/Dev/FunctionalTest.php
+++ b/src/Dev/FunctionalTest.php
@@ -14,6 +14,7 @@ use SilverStripe\Security\BasicAuth;
 use SilverStripe\Security\SecurityToken;
 use SilverStripe\View\SSViewer;
 use SimpleXMLElement;
+use SilverStripe\Dev\Deprecation;
 
 /* -------------------------------------------------
  *
@@ -115,7 +116,7 @@ if (class_exists(IsEqualCanonicalizing::class)) {
 
             // Disable theme, if necessary
             if (static::get_disable_themes()) {
-                SSViewer::config()->update('theme_enabled', false);
+                SSViewer::config()->set('theme_enabled', false);
             }
 
             // Flush user
@@ -123,9 +124,11 @@ if (class_exists(IsEqualCanonicalizing::class)) {
 
             // Switch to draft site, if necessary
             // If you rely on this you should be crafting stage-specific urls instead though.
-            if (static::get_use_draft_site()) {
-                $this->useDraftSite();
-            }
+            Deprecation::withNoReplacement(function () {
+                if (static::get_use_draft_site()) {
+                    $this->useDraftSite();
+                }
+            });
 
             // Unprotect the site, tests are running with the assumption it's off. They will enable it on a case-by-case
             // basis.
@@ -560,7 +563,7 @@ class FunctionalTest extends SapphireTest implements TestOnly
 
         // Disable theme, if necessary
         if (static::get_disable_themes()) {
-            SSViewer::config()->update('theme_enabled', false);
+            SSViewer::config()->set('theme_enabled', false);
         }
 
         // Flush user
@@ -568,9 +571,11 @@ class FunctionalTest extends SapphireTest implements TestOnly
 
         // Switch to draft site, if necessary
         // If you rely on this you should be crafting stage-specific urls instead though.
-        if (static::get_use_draft_site()) {
-            $this->useDraftSite();
-        }
+        Deprecation::withNoReplacement(function () {
+            if (static::get_use_draft_site()) {
+                $this->useDraftSite();
+            }
+        });
 
         // Unprotect the site, tests are running with the assumption it's off. They will enable it on a case-by-case
         // basis.
diff --git a/src/Dev/SapphireTest.php b/src/Dev/SapphireTest.php
index d7b08afc9..4440a00c0 100644
--- a/src/Dev/SapphireTest.php
+++ b/src/Dev/SapphireTest.php
@@ -329,7 +329,7 @@ if (class_exists(IsEqualCanonicalizing::class)) {
             }
 
             if (class_exists(Cookie::class)) {
-                Cookie::config()->update('report_errors', false);
+                Cookie::config()->set('report_errors', false);
             }
 
             if (class_exists(RootURLController::class)) {
@@ -347,16 +347,12 @@ if (class_exists(IsEqualCanonicalizing::class)) {
 
             if ($this->shouldSetupDatabaseForCurrentTest($fixtureFiles)) {
                 // Assign fixture factory to deprecated prop in case old tests use it over the getter
-                /** @var FixtureTestState $fixtureState */
-                $fixtureState = static::$state->getStateByName('fixtures');
-                $this->fixtureFactory = $fixtureState->getFixtureFactory(static::class);
-
                 $this->logInWithPermission('ADMIN');
             }
 
             // turn off template debugging
             if (class_exists(SSViewer::class)) {
-                SSViewer::config()->update('source_file_comments', false);
+                SSViewer::config()->set('source_file_comments', false);
             }
 
             // Set up the test mailer
@@ -1206,7 +1202,7 @@ if (class_exists(IsEqualCanonicalizing::class)) {
             if (strpos($themeBaseDir ?? '', BASE_PATH) === 0) {
                 $themeBaseDir = substr($themeBaseDir ?? '', strlen(BASE_PATH));
             }
-            SSViewer::config()->update('theme_enabled', true);
+            SSViewer::config()->set('theme_enabled', true);
             SSViewer::set_themes([$themeBaseDir . '/themes/' . $theme, '$default']);
 
             try {
@@ -1649,7 +1645,7 @@ class SapphireTest extends PHPUnit_Framework_TestCase implements TestOnly
         }
 
         if (class_exists(Cookie::class)) {
-            Cookie::config()->update('report_errors', false);
+            Cookie::config()->set('report_errors', false);
         }
 
         if (class_exists(RootURLController::class)) {
@@ -1676,7 +1672,7 @@ class SapphireTest extends PHPUnit_Framework_TestCase implements TestOnly
 
         // turn off template debugging
         if (class_exists(SSViewer::class)) {
-            SSViewer::config()->update('source_file_comments', false);
+            SSViewer::config()->set('source_file_comments', false);
         }
 
         // Set up the test mailer
@@ -2556,7 +2552,7 @@ class SapphireTest extends PHPUnit_Framework_TestCase implements TestOnly
         if (strpos($themeBaseDir ?? '', BASE_PATH) === 0) {
             $themeBaseDir = substr($themeBaseDir ?? '', strlen(BASE_PATH));
         }
-        SSViewer::config()->update('theme_enabled', true);
+        SSViewer::config()->set('theme_enabled', true);
         SSViewer::set_themes([$themeBaseDir . '/themes/' . $theme, '$default']);
 
         try {
diff --git a/src/Dev/Tasks/MigrateFileTask.php b/src/Dev/Tasks/MigrateFileTask.php
index 14f2c214b..797e58ec3 100644
--- a/src/Dev/Tasks/MigrateFileTask.php
+++ b/src/Dev/Tasks/MigrateFileTask.php
@@ -21,9 +21,12 @@ use SilverStripe\Dev\BuildTask;
 use SilverStripe\Assets\Dev\Tasks\SecureAssetsMigrationHelper;
 use SilverStripe\UserForms\Task\RecoverUploadLocationsHelper;
 use \Bramus\Monolog\Formatter\ColoredLineFormatter;
+use SilverStripe\Dev\Deprecation;
 
 /**
  * Migrates all 3.x file dataobjects to use the new DBFile field.
+ *
+ * @deprected 4.12.0 Will be removed without equivalent functionality to replace it
  */
 class MigrateFileTask extends BuildTask
 {
@@ -52,6 +55,12 @@ class MigrateFileTask extends BuildTask
     /** @var Logger */
     private $logger;
 
+    public function __construct()
+    {
+        Deprecation::notice('4.12.0', 'Will be removed without equivalent functionality to replace it', Deprecation::SCOPE_CLASS);
+        parent::__construct();
+    }
+
     public function run($request)
     {
         $this->addLogHandlers();
diff --git a/src/Forms/GridField/GridFieldAddExistingAutocompleter.php b/src/Forms/GridField/GridFieldAddExistingAutocompleter.php
index d8efa5903..ff6176d92 100644
--- a/src/Forms/GridField/GridFieldAddExistingAutocompleter.php
+++ b/src/Forms/GridField/GridFieldAddExistingAutocompleter.php
@@ -262,7 +262,7 @@ class GridFieldAddExistingAutocompleter extends AbstractGridFieldComponent imple
 
         $json = [];
         Config::nest();
-        SSViewer::config()->update('source_file_comments', false);
+        SSViewer::config()->set('source_file_comments', false);
         $viewer = SSViewer::fromString($this->resultsFormat);
         foreach ($results as $result) {
             $title = Convert::html2raw($viewer->process($result));
diff --git a/src/Forms/GridField/GridFieldExportButton.php b/src/Forms/GridField/GridFieldExportButton.php
index 9e56b76aa..904219ef2 100644
--- a/src/Forms/GridField/GridFieldExportButton.php
+++ b/src/Forms/GridField/GridFieldExportButton.php
@@ -8,6 +8,7 @@ use SilverStripe\Control\HTTPResponse;
 use SilverStripe\Core\Config\Config;
 use SilverStripe\ORM\DataList;
 use SilverStripe\ORM\DataObject;
+use SilverStripe\ORM\ArrayList;
 
 /**
  * Adds an "Export list" button to the bottom of a {@link GridField}.
@@ -221,6 +222,7 @@ class GridFieldExportButton extends AbstractGridFieldComponent implements GridFi
             ? $gridFieldColumnsComponent->getColumnsHandled($gridField)
             : [];
 
+        /** @var ArrayList|DataList $items */
         // Remove limit as the list may be paginated, we want the full list for the export
         $items = $items->limit(null);
         // Use Generator in applicable cases to reduce memory consumption
diff --git a/src/Forms/GridField/GridFieldFilterHeader.php b/src/Forms/GridField/GridFieldFilterHeader.php
index 6cd457e4c..58599b2fe 100755
--- a/src/Forms/GridField/GridFieldFilterHeader.php
+++ b/src/Forms/GridField/GridFieldFilterHeader.php
@@ -102,7 +102,10 @@ class GridFieldFilterHeader extends AbstractGridFieldComponent implements GridFi
         callable $updateSearchContext = null,
         callable $updateSearchForm = null
     ) {
-        $this->useLegacyFilterHeader = Config::inst()->get(self::class, 'force_legacy') || $useLegacy;
+        $forceLegacy = Deprecation::withNoReplacement(function () {
+            return Config::inst()->get(self::class, 'force_legacy');
+        });
+        $this->useLegacyFilterHeader = $forceLegacy || $useLegacy;
         $this->updateSearchContextCallback = $updateSearchContext;
         $this->updateSearchFormCallback = $updateSearchForm;
     }
@@ -523,7 +526,9 @@ class GridFieldFilterHeader extends AbstractGridFieldComponent implements GridFi
         }
 
         if ($this->useLegacyFilterHeader) {
-            $fieldsList = $this->getLegacyFilterHeader($gridField);
+            $fieldsList = Deprecation::withNoReplacement(function () use ($gridField) {
+                return $this->getLegacyFilterHeader($gridField);
+            });
             $forTemplate->Fields = $fieldsList;
             $filterTemplates = SSViewer::get_templates_by_class($this, '_Row', __CLASS__);
             return ['header' => $forTemplate->renderWith($filterTemplates)];
diff --git a/src/Forms/TreeDropdownField.php b/src/Forms/TreeDropdownField.php
index 69201889f..9ea404844 100644
--- a/src/Forms/TreeDropdownField.php
+++ b/src/Forms/TreeDropdownField.php
@@ -2,7 +2,6 @@
 
 namespace SilverStripe\Forms;
 
-use SilverStripe\Dev\Deprecation;
 use Exception;
 use InvalidArgumentException;
 use SilverStripe\Assets\Folder;
@@ -622,13 +621,11 @@ class TreeDropdownField extends FormField
     /**
      * HTML-encoded label for this node, including css classes and other markup.
      *
-     * @deprecated 4.0.1 Use setTitleField() instead
      * @param string $field
      * @return $this
      */
     public function setLabelField($field)
     {
-        Deprecation::notice('4.0.1', 'Use setTitleField() instead');
         $this->labelField = $field;
         return $this;
     }
@@ -636,12 +633,10 @@ class TreeDropdownField extends FormField
     /**
      * HTML-encoded label for this node, including css classes and other markup.
      *
-     * @deprecated 4.0.1 Use getTitleField() instead
      * @return string
      */
     public function getLabelField()
     {
-        Deprecation::notice('4.0.1', 'Use getTitleField() instead');
         return $this->labelField;
     }
 
diff --git a/src/Forms/UploadReceiver.php b/src/Forms/UploadReceiver.php
index fda6a617d..9d745b0d4 100644
--- a/src/Forms/UploadReceiver.php
+++ b/src/Forms/UploadReceiver.php
@@ -6,6 +6,7 @@ namespace SilverStripe\Forms;
 use SilverStripe\Assets\File;
 use SilverStripe\Assets\Upload;
 use SilverStripe\Assets\Upload_Validator;
+use SilverStripe\Core\Convert;
 
 /**
  * Represents a form field which has an Upload() instance and can upload to a folder
@@ -47,8 +48,8 @@ trait UploadReceiver
         );
 
         // get the lower max size
-        $maxUpload = File::ini2bytes(ini_get('upload_max_filesize'));
-        $maxPost = File::ini2bytes(ini_get('post_max_size'));
+        $maxUpload = Convert::memstring2bytes(ini_get('upload_max_filesize'));
+        $maxPost = Convert::memstring2bytes(ini_get('post_max_size'));
         $this->getValidator()->setAllowedMaxFileSize(min($maxUpload, $maxPost));
     }
 
diff --git a/src/ORM/ArrayList.php b/src/ORM/ArrayList.php
index 74a7cd600..83e448b93 100644
--- a/src/ORM/ArrayList.php
+++ b/src/ORM/ArrayList.php
@@ -178,18 +178,20 @@ class ArrayList extends ViewableData implements SS_List, Filterable, Sortable, L
 
     /**
      * Get a sub-range of this dataobjectset as an array
+     * Pass null to "remove the limit" - this is for consistency with DataList::limit(null) which itself will
+     * call SQLSelect::setLimit(null)
      *
-     * @param int $length
+     * @param int|null $length
      * @param int $offset
      * @return static
      */
     public function limit($length, $offset = 0)
     {
         // Type checking: designed for consistency with DataList::limit()
-        if (!is_numeric($length) || !is_numeric($offset)) {
+        if ((!is_numeric($length) || !is_numeric($offset)) && !is_null($length)) {
             Deprecation::notice(
                 '4.3',
-                'Arguments to ArrayList::limit() should be numeric'
+                'Arguments to ArrayList::limit() should be numeric or null'
             );
         }
 
diff --git a/src/ORM/Connect/DBSchemaManager.php b/src/ORM/Connect/DBSchemaManager.php
index 698f17cd5..4a8936228 100644
--- a/src/ORM/Connect/DBSchemaManager.php
+++ b/src/ORM/Connect/DBSchemaManager.php
@@ -2,7 +2,6 @@
 
 namespace SilverStripe\ORM\Connect;
 
-use SilverStripe\Dev\Deprecation;
 use Exception;
 use SilverStripe\Control\Director;
 use SilverStripe\Core\Config\Config;
@@ -60,12 +59,9 @@ abstract class DBSchemaManager
     /**
      * @param string $table
      * @param string $class
-     *
-     * @deprecated 4.0.1 Will be removed without equivalent functionality
      */
     public static function showTableNameWarning($table, $class)
     {
-        Deprecation::notice('4.0.1', 'Will be removed without equivalent functionality');
         static::$table_name_warnings[$table] = $class;
     }
 
diff --git a/src/ORM/Connect/MySQLTransactionManager.php b/src/ORM/Connect/MySQLTransactionManager.php
index 452ce334a..b4d9d1a62 100644
--- a/src/ORM/Connect/MySQLTransactionManager.php
+++ b/src/ORM/Connect/MySQLTransactionManager.php
@@ -20,13 +20,6 @@ class MySQLTransactionManager implements TransactionManager
 
     public function transactionStart($transactionMode = false, $sessionCharacteristics = false)
     {
-        if ($transactionMode || $sessionCharacteristics) {
-            Deprecation::notice(
-                '4.4',
-                '$transactionMode and $sessionCharacteristics are deprecated and will be removed in SS5'
-            );
-        }
-
         if ($this->inTransaction) {
             throw new DatabaseException(
                 "Already in transaction, can't start another. Consider decorating with NestedTransactionManager."
diff --git a/src/ORM/DataObject.php b/src/ORM/DataObject.php
index aac5f79cb..9d92c4086 100644
--- a/src/ORM/DataObject.php
+++ b/src/ORM/DataObject.php
@@ -2604,11 +2604,6 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 
         // Support for the old method during the deprecation period
         if ($this->hasMethod('getCMSValidator')) {
-            Deprecation::notice(
-                '4.6',
-                'getCMSValidator() is removed in 5.0 in favour of getCMSCompositeValidator()'
-            );
-
             $compositeValidator->addValidator($this->getCMSValidator());
         }
 
diff --git a/src/Security/CMSSecurity.php b/src/Security/CMSSecurity.php
index eadd22e12..1aedbcf69 100644
--- a/src/Security/CMSSecurity.php
+++ b/src/Security/CMSSecurity.php
@@ -187,7 +187,7 @@ PHP
         $backURLs = [
             $this->getRequest()->requestVar('BackURL'),
             $this->getRequest()->getSession()->get('BackURL'),
-            Director::absoluteURL(AdminRootController::config()->get('url_base'), true),
+            Director::absoluteURL(AdminRootController::config()->get('url_base')),
         ];
         $backURL = null;
         foreach ($backURLs as $backURL) {
diff --git a/src/View/SSViewer.php b/src/View/SSViewer.php
index 6dafb12f4..2057f5974 100644
--- a/src/View/SSViewer.php
+++ b/src/View/SSViewer.php
@@ -287,8 +287,11 @@ class SSViewer implements Flushable
             return $themes;
         }
 
-        // Support legacy behaviour
-        if ($theme = SSViewer::config()->uninherited('theme')) {
+        // Support @deprecated legacy behaviour
+        $theme = Deprecation::withNoReplacement(function () {
+            return SSViewer::config()->uninherited('theme');
+        });
+        if ($theme) {
             return [self::PUBLIC_THEME, $theme, self::DEFAULT_THEME];
         }
 
diff --git a/src/i18n/i18n.php b/src/i18n/i18n.php
index 597a7ecec..b7357b802 100644
--- a/src/i18n/i18n.php
+++ b/src/i18n/i18n.php
@@ -178,7 +178,6 @@ class i18n implements TemplateGlobalProvider
         // inject the variables from injectionArray (if present)
         $sprintfArgs = [];
         if ($default && !preg_match('/\{[\w\d]*\}/i', $default ?? '') && preg_match('/%[s,d]/', $default ?? '')) {
-            Deprecation::notice('5.0', 'sprintf style localisation variables are deprecated');
             $sprintfArgs = array_values($injection ?? []);
             $injection = [];
         }
diff --git a/templates/SilverStripe/Forms/GridField/GridField_Item.ss b/templates/SilverStripe/Forms/GridField/GridField_Item.ss
index ed5a5fe15..c57cd94df 100644
--- a/templates/SilverStripe/Forms/GridField/GridField_Item.ss
+++ b/templates/SilverStripe/Forms/GridField/GridField_Item.ss
@@ -6,7 +6,7 @@
 		<td colspan="$GridField.ExtraColumnsCount" class="ss-gridfield-last"></td>
 	<% else %>
 		<% loop $Fields %>
-			<td <% if FirstLast %>class="ss-gridfield-{$FirstLast}"<% end_if %>>$Value</td>
+			<td <% if $FirstLast %>class="ss-gridfield-{$FirstLast}"<% end_if %>>$Value</td>
 		<% end_loop %>
 	<% end_if %>
 </tr>
diff --git a/tests/php/Control/ControllerTest.php b/tests/php/Control/ControllerTest.php
index def255c6b..34559386e 100644
--- a/tests/php/Control/ControllerTest.php
+++ b/tests/php/Control/ControllerTest.php
@@ -45,7 +45,7 @@ class ControllerTest extends FunctionalTest
     protected function setUp(): void
     {
         parent::setUp();
-        Director::config()->update('alternate_base_url', '/');
+        Director::config()->set('alternate_base_url', '/');
 
         // Add test theme
         $themeDir = substr(__DIR__, strlen(FRAMEWORK_DIR)) . '/ControllerTest/';
diff --git a/tests/php/Control/DirectorTest.php b/tests/php/Control/DirectorTest.php
index 05e24046b..44c9e1980 100644
--- a/tests/php/Control/DirectorTest.php
+++ b/tests/php/Control/DirectorTest.php
@@ -16,6 +16,7 @@ use SilverStripe\Core\Config\Config;
 use SilverStripe\Core\Injector\Injector;
 use SilverStripe\Core\Environment;
 use SilverStripe\Core\Kernel;
+use SilverStripe\Dev\Deprecation;
 use SilverStripe\Dev\SapphireTest;
 
 /**
@@ -856,6 +857,9 @@ class DirectorTest extends SapphireTest
 
     public function testRequestFilterInDirectorTest()
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
         $filter = new DirectorTest\TestRequestFilter;
 
         $processor = new RequestProcessor([$filter]);
diff --git a/tests/php/Control/Email/EmailTest.php b/tests/php/Control/Email/EmailTest.php
index daa69ae41..462d51f1b 100644
--- a/tests/php/Control/Email/EmailTest.php
+++ b/tests/php/Control/Email/EmailTest.php
@@ -271,7 +271,7 @@ class EmailTest extends SapphireTest
 
     public function testSetSwiftMessage()
     {
-        Email::config()->update('admin_email', 'admin@example.com');
+        Email::config()->set('admin_email', 'admin@example.com');
         DBDatetime::set_mock_now('2017-01-01 07:00:00');
         $email = new Email();
         $swiftMessage = new Swift_Message();
@@ -294,7 +294,7 @@ class EmailTest extends SapphireTest
 
     public function testAdminEmailApplied()
     {
-        Email::config()->update('admin_email', 'admin@example.com');
+        Email::config()->set('admin_email', 'admin@example.com');
         $email = new Email();
 
         $this->assertCount(1, $email->getFrom());
diff --git a/tests/php/Control/Email/SwiftMailerTest.php b/tests/php/Control/Email/SwiftMailerTest.php
index 43a7f98d1..51161a52b 100644
--- a/tests/php/Control/Email/SwiftMailerTest.php
+++ b/tests/php/Control/Email/SwiftMailerTest.php
@@ -21,7 +21,7 @@ class SwiftMailerTest extends SapphireTest
         $this->assertEquals($swift, $mailer->getSwiftMailer());
 
         SwiftMailer::config()->remove('swift_plugins');
-        SwiftMailer::config()->update('swift_plugins', [Swift_Plugins_AntiFloodPlugin::class]);
+        SwiftMailer::config()->merge('swift_plugins', [Swift_Plugins_AntiFloodPlugin::class]);
 
         /** @var Swift_MailTransport $transport */
         $transport = $this->getMockBuilder(Swift_MailTransport::class)->getMock();
diff --git a/tests/php/Control/Email/SwiftPluginTest.php b/tests/php/Control/Email/SwiftPluginTest.php
index 5ca702d8e..231e6a523 100644
--- a/tests/php/Control/Email/SwiftPluginTest.php
+++ b/tests/php/Control/Email/SwiftPluginTest.php
@@ -39,7 +39,7 @@ class SwiftPluginTest extends SapphireTest
 
     public function testSendAllEmailsTo()
     {
-        Email::config()->update('send_all_emails_to', 'to@example.com');
+        Email::config()->set('send_all_emails_to', 'to@example.com');
         $email = $this->getEmail();
         $this->getMailer()->send($email->getSwiftMessage());
         $headers = $email->getSwiftMessage()->getHeaders();
@@ -68,7 +68,7 @@ class SwiftPluginTest extends SapphireTest
 
     public function testSendAllEmailsFrom()
     {
-        Email::config()->update('send_all_emails_from', 'from@example.com');
+        Email::config()->set('send_all_emails_from', 'from@example.com');
         $email = $this->getEmail();
         $this->getMailer()->send($email->getSwiftMessage());
 
@@ -88,7 +88,7 @@ class SwiftPluginTest extends SapphireTest
 
     public function testCCAllEmailsTo()
     {
-        Email::config()->update('cc_all_emails_to', 'cc@example.com');
+        Email::config()->set('cc_all_emails_to', 'cc@example.com');
         $email = $this->getEmail();
         $this->getMailer()->send($email->getSwiftMessage());
 
@@ -99,7 +99,7 @@ class SwiftPluginTest extends SapphireTest
 
     public function testBCCAllEmailsTo()
     {
-        Email::config()->update('bcc_all_emails_to', 'bcc@example.com');
+        Email::config()->set('bcc_all_emails_to', 'bcc@example.com');
         $email = $this->getEmail();
         $this->getMailer()->send($email->getSwiftMessage());
 
diff --git a/tests/php/Control/HTTPRequestTest.php b/tests/php/Control/HTTPRequestTest.php
index cf0acc0ca..8f39efbc2 100644
--- a/tests/php/Control/HTTPRequestTest.php
+++ b/tests/php/Control/HTTPRequestTest.php
@@ -6,6 +6,7 @@ use ReflectionMethod;
 use SilverStripe\Control\HTTPRequest;
 use SilverStripe\Control\Middleware\TrustedProxyMiddleware;
 use SilverStripe\Control\Session;
+use SilverStripe\Dev\Deprecation;
 use SilverStripe\Dev\SapphireTest;
 
 class HTTPRequestTest extends SapphireTest
@@ -155,12 +156,18 @@ class HTTPRequestTest extends SapphireTest
      */
     public function testDetectMethod($realMethod, $post, $expected)
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
         $actual = HTTPRequest::detect_method($realMethod, $post);
         $this->assertEquals($expected, $actual);
     }
 
     public function testBadDetectMethod()
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
         $this->expectException(\InvalidArgumentException::class);
         HTTPRequest::detect_method('POST', ['_method' => 'Boom']);
     }
diff --git a/tests/php/Control/HTTPTest.php b/tests/php/Control/HTTPTest.php
index 4d43f16b9..b7ea02e9d 100644
--- a/tests/php/Control/HTTPTest.php
+++ b/tests/php/Control/HTTPTest.php
@@ -11,6 +11,7 @@ use SilverStripe\Control\Middleware\HTTPCacheControlMiddleware;
 use SilverStripe\Control\Session;
 use SilverStripe\Core\Config\Config;
 use SilverStripe\Dev\FunctionalTest;
+use SilverStripe\Dev\Deprecation;
 
 /**
  * Tests the {@link HTTP} class
@@ -115,6 +116,9 @@ class HTTPTest extends FunctionalTest
 
     public function testDeprecatedVaryHandling()
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
         /** @var Config */
         Config::modify()->set(
             HTTP::class,
@@ -129,6 +133,9 @@ class HTTPTest extends FunctionalTest
 
     public function testDeprecatedCacheControlHandling()
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
         HTTPCacheControlMiddleware::singleton()->publicCache();
 
         /** @var Config */
@@ -149,6 +156,9 @@ class HTTPTest extends FunctionalTest
 
     public function testDeprecatedCacheControlHandlingOnMaxAge()
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
         HTTPCacheControlMiddleware::singleton()->publicCache();
 
         /** @var Config */
@@ -169,6 +179,9 @@ class HTTPTest extends FunctionalTest
 
     public function testDeprecatedCacheControlHandlingThrowsWithUnknownDirectives()
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
         $this->expectException(\LogicException::class);
         $this->expectExceptionMessageMatches('/Found unsupported legacy directives in HTTP\.cache_control: unknown/');
         /** @var Config */
diff --git a/tests/php/Control/SessionTest.php b/tests/php/Control/SessionTest.php
index e37396448..e0b4d4c49 100644
--- a/tests/php/Control/SessionTest.php
+++ b/tests/php/Control/SessionTest.php
@@ -107,7 +107,7 @@ class SessionTest extends SapphireTest
             ->setScheme('https');
         Cookie::set(session_name(), '1234');
         $session = new Session(null); // unstarted session
-        $session->config()->update('cookie_secure', true);
+        $session->config()->set('cookie_secure', true);
         $session->start($req);
         $this->assertEquals(session_name(), $session->config()->get('cookie_name_secure'));
     }
@@ -270,7 +270,7 @@ class SessionTest extends SapphireTest
             ->setScheme('https');
         $session = new Session(null); // unstarted session
         Cookie::set($session->config()->get('cookie_name_secure'), '1234');
-        $session->config()->update('cookie_secure', true);
+        $session->config()->set('cookie_secure', true);
         $this->assertTrue($session->requestContainsSessionId($req));
     }
 
diff --git a/tests/php/Core/ConvertTest.php b/tests/php/Core/ConvertTest.php
index 6522fb39e..1c846f974 100644
--- a/tests/php/Core/ConvertTest.php
+++ b/tests/php/Core/ConvertTest.php
@@ -5,6 +5,7 @@ namespace SilverStripe\Core\Tests;
 use Exception;
 use InvalidArgumentException;
 use SilverStripe\Core\Convert;
+use SilverStripe\Dev\Deprecation;
 use SilverStripe\Dev\SapphireTest;
 use SilverStripe\View\Parsers\URLSegmentFilter;
 use stdClass;
@@ -217,6 +218,9 @@ PHP
      */
     public function testArray2JSON()
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
         $val = [
          'Joe' => 'Bloggs',
          'Tom' => 'Jones',
@@ -237,6 +241,9 @@ PHP
      */
     public function testJSON2Array()
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
         $val = '{"Joe":"Bloggs","Tom":"Jones","My":{"Complicated":"Structure"}}';
         $decoded = Convert::json2array($val);
         $this->assertEquals(3, count($decoded ?? []), '3 items in the decoded array');
@@ -250,6 +257,9 @@ PHP
      */
     public function testJSON2Obj()
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
         $val = '{"Joe":"Bloggs","Tom":"Jones","My":{"Complicated":"Structure"}}';
         $obj = Convert::json2obj($val);
         $this->assertEquals('Bloggs', $obj->Joe);
@@ -264,7 +274,7 @@ PHP
      */
     public function testRaw2URL()
     {
-        URLSegmentFilter::config()->update('default_allow_multibyte', false);
+        URLSegmentFilter::config()->set('default_allow_multibyte', false);
         $this->assertEquals('foo', Convert::raw2url('foo'));
         $this->assertEquals('foo-and-bar', Convert::raw2url('foo & bar'));
         $this->assertEquals('foo-and-bar', Convert::raw2url('foo &amp; bar!'));
@@ -359,6 +369,9 @@ PHP
      */
     public function testRaw2JSON()
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
 
         // Test object
         $input = new stdClass();
@@ -390,6 +403,9 @@ PHP
      */
     public function testRaw2JsonWithContext()
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
         $data = ['foo' => 'b"ar'];
         $expected = '{"foo":"b\u0022ar"}';
         $result = Convert::raw2json($data, JSON_HEX_QUOT);
diff --git a/tests/php/Core/Manifest/ModuleTest.php b/tests/php/Core/Manifest/ModuleTest.php
index f4ea2db5a..a0e9f6a0f 100644
--- a/tests/php/Core/Manifest/ModuleTest.php
+++ b/tests/php/Core/Manifest/ModuleTest.php
@@ -5,6 +5,7 @@ namespace SilverStripe\Core\Tests\Manifest;
 use SilverStripe\Control\Director;
 use SilverStripe\Core\Manifest\Module;
 use SilverStripe\Dev\SapphireTest;
+use SilverStripe\Dev\Deprecation;
 
 class ModuleTest extends SapphireTest
 {
@@ -29,6 +30,9 @@ class ModuleTest extends SapphireTest
      */
     public function testGetCIConfig($fixture, $expectedPhpConfig)
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
         $path = __DIR__ . '/fixtures/phpunit-detection/' . $fixture;
         $module = new Module($path, $path);
         $this->assertEquals(
diff --git a/tests/php/Core/ObjectTest.php b/tests/php/Core/ObjectTest.php
index 969fdaf7a..66562315a 100644
--- a/tests/php/Core/ObjectTest.php
+++ b/tests/php/Core/ObjectTest.php
@@ -19,6 +19,7 @@ use SilverStripe\Core\Tests\ObjectTest\ExtensionTest3;
 use SilverStripe\Core\Tests\ObjectTest\MyObject;
 use SilverStripe\Core\Tests\ObjectTest\MySubObject;
 use SilverStripe\Core\Tests\ObjectTest\TestExtension;
+use SilverStripe\Dev\Deprecation;
 use SilverStripe\Dev\SapphireTest;
 use SilverStripe\Versioned\Versioned;
 
@@ -110,6 +111,9 @@ class ObjectTest extends SapphireTest
 
     public function testStaticGetterMethod()
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
         $obj = singleton(MyObject::class);
         $this->assertEquals(
             'MyObject',
@@ -120,6 +124,9 @@ class ObjectTest extends SapphireTest
 
     public function testStaticInheritanceGetters()
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
         $subObj = singleton(MyObject::class);
         $this->assertEquals(
             $subObj->stat('mystaticProperty'),
@@ -130,6 +137,9 @@ class ObjectTest extends SapphireTest
 
     public function testStaticSettingOnSingletons()
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
         $singleton1 = singleton(MyObject::class);
         $singleton2 = singleton(MyObject::class);
         $singleton1->set_stat('mystaticProperty', 'changed');
@@ -142,6 +152,9 @@ class ObjectTest extends SapphireTest
 
     public function testStaticSettingOnInstances()
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
         $instance1 = new ObjectTest\MyObject();
         $instance2 = new ObjectTest\MyObject();
         $instance1->set_stat('mystaticProperty', 'changed');
diff --git a/tests/php/Dev/BacktraceTest.php b/tests/php/Dev/BacktraceTest.php
index de44410d1..d1f5fe98d 100644
--- a/tests/php/Dev/BacktraceTest.php
+++ b/tests/php/Dev/BacktraceTest.php
@@ -59,7 +59,7 @@ class BacktraceTest extends SapphireTest
                 'args' => ['myarg' => 'myval']
             ]
         ];
-        Backtrace::config()->update(
+        Backtrace::config()->merge(
             'ignore_function_args',
             [
                 ['MyClass', 'myIgnoredClassFunction'],
@@ -101,7 +101,7 @@ class BacktraceTest extends SapphireTest
                 'args' => ['myarg' => 'myval']
             ]
         ];
-        Backtrace::config()->update(
+        Backtrace::config()->merge(
             'ignore_function_args',
             [
                 ['*', 'myIgnoredClassFunction'],
diff --git a/tests/php/Dev/DeprecationTest.php b/tests/php/Dev/DeprecationTest.php
index b447866a0..fac1ad726 100644
--- a/tests/php/Dev/DeprecationTest.php
+++ b/tests/php/Dev/DeprecationTest.php
@@ -7,6 +7,7 @@ use SilverStripe\Core\Config\Config;
 use SilverStripe\Dev\Deprecation;
 use SilverStripe\Dev\SapphireTest;
 use SilverStripe\Dev\Tests\DeprecationTest\DeprecationTestObject;
+use SilverStripe\Core\Injector\Injector;
 
 class DeprecationTest extends SapphireTest
 {
@@ -16,6 +17,8 @@ class DeprecationTest extends SapphireTest
 
     private $oldHandler = null;
 
+    private bool $noticesWereEnabled = false;
+
     protected function setup(): void
     {
         // Use custom error handler for two reasons:
@@ -23,6 +26,7 @@ class DeprecationTest extends SapphireTest
         // - Allow the use of expectDeprecation(), which doesn't work with E_USER_DEPRECATION by default
         //   https://github.com/laminas/laminas-di/pull/30#issuecomment-927585210
         parent::setup();
+        $this->noticesWereEnabled = Deprecation::isEnabled();
         $this->oldHandler = set_error_handler(function (int $errno, string $errstr, string $errfile, int $errline) {
             if ($errno === E_USER_DEPRECATED) {
                 if (str_contains($errstr, 'SilverStripe\\Dev\\Tests\\DeprecationTest')) {
@@ -42,23 +46,140 @@ class DeprecationTest extends SapphireTest
 
     protected function tearDown(): void
     {
-        Deprecation::disable();
+        if (!$this->noticesWereEnabled) {
+            Deprecation::disable();
+        }
         restore_error_handler();
         $this->oldHandler = null;
         parent::tearDown();
     }
 
+    private function myDeprecatedMethod(): string
+    {
+        Deprecation::notice('1.2.3', 'My message');
+        return 'abc';
+    }
+
     public function testNotice()
     {
         $message = implode(' ', [
-            'SilverStripe\Dev\Tests\DeprecationTest->testNotice is deprecated.',
+            'SilverStripe\Dev\Tests\DeprecationTest->myDeprecatedMethod is deprecated.',
             'My message.',
-            'Called from PHPUnit\Framework\TestCase->runTest.'
+            'Called from SilverStripe\Dev\Tests\DeprecationTest->testNotice.'
         ]);
         $this->expectDeprecation();
         $this->expectDeprecationMessage($message);
         Deprecation::enable();
-        Deprecation::notice('1.2.3', 'My message');
+        $ret = $this->myDeprecatedMethod();
+        $this->assertSame('abc', $ret);
+        // call outputNotices() directly because the regular shutdown function that emits
+        // the notices within Deprecation won't be called until after this unit-test has finished
+        Deprecation::outputNotices();
+    }
+
+    public function testCallUserFunc()
+    {
+        $message = implode(' ', [
+            'SilverStripe\Dev\Tests\DeprecationTest->myDeprecatedMethod is deprecated.',
+            'My message.',
+            'Called from SilverStripe\Dev\Tests\DeprecationTest->testCallUserFunc.'
+        ]);
+        $this->expectDeprecation();
+        $this->expectDeprecationMessage($message);
+        Deprecation::enable();
+        $ret = call_user_func([$this, 'myDeprecatedMethod']);
+        $this->assertSame('abc', $ret);
+        Deprecation::outputNotices();
+    }
+
+    public function testCallUserFuncArray()
+    {
+        $message = implode(' ', [
+            'SilverStripe\Dev\Tests\DeprecationTest->myDeprecatedMethod is deprecated.',
+            'My message.',
+            'Called from SilverStripe\Dev\Tests\DeprecationTest->testCallUserFuncArray.'
+        ]);
+        $this->expectDeprecation();
+        $this->expectDeprecationMessage($message);
+        Deprecation::enable();
+        $ret = call_user_func_array([$this, 'myDeprecatedMethod'], []);
+        $this->assertSame('abc', $ret);
+        Deprecation::outputNotices();
+    }
+
+    public function testWithNoReplacementDefault()
+    {
+        Deprecation::enable();
+        $ret = Deprecation::withNoReplacement(function () {
+            return $this->myDeprecatedMethod();
+        });
+        $this->assertSame('abc', $ret);
+        Deprecation::outputNotices();
+    }
+
+    public function testWithNoReplacementTrue()
+    {
+        $message = implode(' ', [
+            'SilverStripe\Dev\Tests\DeprecationTest->myDeprecatedMethod is deprecated.',
+            'My message.',
+            'Called from SilverStripe\Dev\Tests\DeprecationTest->testWithNoReplacementTrue.'
+        ]);
+        $this->expectDeprecation();
+        $this->expectDeprecationMessage($message);
+        Deprecation::enable(true);
+        $ret = Deprecation::withNoReplacement(function () {
+            return $this->myDeprecatedMethod();
+        });
+        $this->assertSame('abc', $ret);
+        Deprecation::outputNotices();
+    }
+
+    public function testWithNoReplacementTrueCallUserFunc()
+    {
+        $message = implode(' ', [
+            'SilverStripe\Dev\Tests\DeprecationTest->myDeprecatedMethod is deprecated.',
+            'My message.',
+            'Called from SilverStripe\Dev\Tests\DeprecationTest->testWithNoReplacementTrueCallUserFunc.'
+        ]);
+        $this->expectDeprecation();
+        $this->expectDeprecationMessage($message);
+        Deprecation::enable(true);
+        $ret = Deprecation::withNoReplacement(function () {
+            return call_user_func([$this, 'myDeprecatedMethod']);
+        });
+        $this->assertSame('abc', $ret);
+        Deprecation::outputNotices();
+    }
+
+    public function testClassWithNoReplacement()
+    {
+        $message = implode(' ', [
+            'SilverStripe\Dev\Tests\DeprecationTest\DeprecationTestObject is deprecated.',
+            'Some class message.',
+            'Called from SilverStripe\Dev\Tests\DeprecationTest->testClassWithNoReplacement.'
+        ]);
+        $this->expectDeprecation();
+        $this->expectDeprecationMessage($message);
+        Deprecation::enable(true);
+        // using this syntax because my IDE was complaining about DeprecationTestObject not existing
+        // when trying to use `new DeprecationTestObject();`
+        $class = DeprecationTestObject::class;
+        new $class();
+        Deprecation::outputNotices();
+    }
+
+    public function testClassWithInjectorWithNoReplacement()
+    {
+        $message = implode(' ', [
+            'SilverStripe\Dev\Tests\DeprecationTest\DeprecationTestObject is deprecated.',
+            'Some class message.',
+            'Called from SilverStripe\Dev\Tests\DeprecationTest->testClassWithInjectorWithNoReplacement.'
+        ]);
+        $this->expectDeprecation();
+        $this->expectDeprecationMessage($message);
+        Deprecation::enable(true);
+        Injector::inst()->get(DeprecationTestObject::class);
+        Deprecation::outputNotices();
     }
 
     /**
@@ -66,8 +187,12 @@ class DeprecationTest extends SapphireTest
      */
     public function testDisabled()
     {
+        if ($this->noticesWereEnabled) {
+            $this->markTestSkipped('Notices are enabled for this project outside of this unit test');
+        }
         // test that no error error is raised because by default Deprecation is disabled
-        Deprecation::notice('4.5.6', 'My message');
+        $this->myDeprecatedMethod();
+        Deprecation::outputNotices();
     }
 
     // The following tests would be better to put in the silverstripe/config module, however this is not
@@ -76,7 +201,6 @@ class DeprecationTest extends SapphireTest
     // Adding a _config.php file will break existing unit-tests within silverstripe/config
     // It is possible to put DeprecationTestObject in framework and the unit tests in config, however
     // that's probably messier then just having everything within framework
-
     public function testConfigGetFirst()
     {
         $message = implode(' ', [
@@ -87,6 +211,7 @@ class DeprecationTest extends SapphireTest
         $this->expectDeprecationMessage($message);
         Deprecation::enable();
         Config::inst()->get(DeprecationTestObject::class, 'first_config');
+        Deprecation::outputNotices();
     }
 
     public function testConfigGetSecond()
@@ -99,6 +224,7 @@ class DeprecationTest extends SapphireTest
         $this->expectDeprecationMessage($message);
         Deprecation::enable();
         Config::inst()->get(DeprecationTestObject::class, 'second_config');
+        Deprecation::outputNotices();
     }
 
     public function testConfigGetThird()
@@ -108,6 +234,7 @@ class DeprecationTest extends SapphireTest
         $this->expectDeprecationMessage($message);
         Deprecation::enable();
         Config::inst()->get(DeprecationTestObject::class, 'third_config');
+        Deprecation::outputNotices();
     }
 
     public function testConfigSet()
@@ -120,6 +247,7 @@ class DeprecationTest extends SapphireTest
         $this->expectDeprecationMessage($message);
         Deprecation::enable();
         Config::modify()->set(DeprecationTestObject::class, 'first_config', 'abc');
+        Deprecation::outputNotices();
     }
 
     public function testConfigMerge()
@@ -132,5 +260,6 @@ class DeprecationTest extends SapphireTest
         $this->expectDeprecationMessage($message);
         Deprecation::enable();
         Config::modify()->merge(DeprecationTestObject::class, 'array_config', ['abc']);
+        Deprecation::outputNotices();
     }
 }
diff --git a/tests/php/Dev/DeprecationTest/DeprecationTestObject.php b/tests/php/Dev/DeprecationTest/DeprecationTestObject.php
index c16a83710..60a725458 100644
--- a/tests/php/Dev/DeprecationTest/DeprecationTestObject.php
+++ b/tests/php/Dev/DeprecationTest/DeprecationTestObject.php
@@ -4,9 +4,22 @@ namespace SilverStripe\Dev\Tests\DeprecationTest;
 
 use SilverStripe\Dev\TestOnly;
 use SilverStripe\ORM\DataObject;
+use SilverStripe\Dev\Deprecation;
 
 class DeprecationTestObject extends DataObject implements TestOnly
 {
+    public function __construct()
+    {
+        parent::__construct();
+        Deprecation::withNoReplacement(function () {
+            Deprecation::notice(
+                '1.2.3',
+                'Some class message',
+                Deprecation::SCOPE_CLASS
+            );
+        });
+    }
+
     private static $db = [
         "Name" => "Varchar"
     ];
diff --git a/tests/php/Dev/DevAdminControllerTest.php b/tests/php/Dev/DevAdminControllerTest.php
index 8a64b3f71..60e93fed0 100644
--- a/tests/php/Dev/DevAdminControllerTest.php
+++ b/tests/php/Dev/DevAdminControllerTest.php
@@ -18,7 +18,7 @@ class DevAdminControllerTest extends FunctionalTest
     {
         parent::setUp();
 
-        DevelopmentAdmin::config()->update(
+        DevelopmentAdmin::config()->merge(
             'registered_controllers',
             [
             'x1' => [
diff --git a/tests/php/Forms/ConfirmedPasswordFieldTest.php b/tests/php/Forms/ConfirmedPasswordFieldTest.php
index 20be81893..990402db0 100644
--- a/tests/php/Forms/ConfirmedPasswordFieldTest.php
+++ b/tests/php/Forms/ConfirmedPasswordFieldTest.php
@@ -200,7 +200,7 @@ class ConfirmedPasswordFieldTest extends SapphireTest
         $this->assertSame($expectValid, $result, 'Validate method should return its result');
         $this->assertSame($expectValid, $validator->getResult()->isValid());
         if ($expectedMessage) {
-            $this->assertStringContainsString($expectedMessage, $validator->getResult()->serialize());
+            $this->assertStringContainsString($expectedMessage, json_encode($validator->getResult()->__serialize()));
         }
     }
 
@@ -235,7 +235,7 @@ class ConfirmedPasswordFieldTest extends SapphireTest
         $this->assertFalse($validator->getResult()->isValid());
         $this->assertStringContainsString(
             'Passwords must have at least one digit and one alphanumeric character',
-            $validator->getResult()->serialize()
+            json_encode($validator->getResult()->__serialize())
         );
     }
 
@@ -254,7 +254,7 @@ class ConfirmedPasswordFieldTest extends SapphireTest
         $this->assertFalse($validator->getResult()->isValid());
         $this->assertStringContainsString(
             'You must enter your current password',
-            $validator->getResult()->serialize()
+            json_encode($validator->getResult()->__serialize())
         );
     }
 
@@ -276,7 +276,7 @@ class ConfirmedPasswordFieldTest extends SapphireTest
         $this->assertFalse($validator->getResult()->isValid());
         $this->assertStringContainsString(
             'You must be logged in to change your password',
-            $validator->getResult()->serialize()
+            json_encode($validator->getResult()->__serialize())
         );
     }
 
@@ -302,7 +302,7 @@ class ConfirmedPasswordFieldTest extends SapphireTest
         $this->assertFalse($validator->getResult()->isValid());
         $this->assertStringContainsString(
             'The current password you have entered is not correct',
-            $validator->getResult()->serialize()
+            json_encode($validator->getResult()->__serialize())
         );
     }
 
diff --git a/tests/php/Forms/CurrencyFieldDisabledTest.php b/tests/php/Forms/CurrencyFieldDisabledTest.php
index 6f1cc0c70..d02e1375a 100644
--- a/tests/php/Forms/CurrencyFieldDisabledTest.php
+++ b/tests/php/Forms/CurrencyFieldDisabledTest.php
@@ -23,7 +23,7 @@ class CurrencyFieldDisabledTest extends SapphireTest
      */
     public function testFieldWithCustomisedCurrencySymbol()
     {
-        DBCurrency::config()->update('currency_symbol', '€');
+        DBCurrency::config()->set('currency_symbol', '€');
         $field = new CurrencyField_Disabled('Test', '', '€5.00');
         $result = $field->Field();
 
diff --git a/tests/php/Forms/CurrencyFieldReadonlyTest.php b/tests/php/Forms/CurrencyFieldReadonlyTest.php
index 0c998a8ef..352b97f82 100644
--- a/tests/php/Forms/CurrencyFieldReadonlyTest.php
+++ b/tests/php/Forms/CurrencyFieldReadonlyTest.php
@@ -28,7 +28,7 @@ class CurrencyFieldReadonlyTest extends SapphireTest
 
     public function testFieldWithOutValue()
     {
-        DBCurrency::config()->update('currency_symbol', 'AUD');
+        DBCurrency::config()->set('currency_symbol', 'AUD');
         $field = new CurrencyField_Readonly('Test', '', null);
         $result = $field->Field();
 
@@ -42,7 +42,7 @@ class CurrencyFieldReadonlyTest extends SapphireTest
      */
     public function testFieldWithCustomisedCurrencySymbol()
     {
-        DBCurrency::config()->update('currency_symbol', '€');
+        DBCurrency::config()->set('currency_symbol', '€');
         $field = new CurrencyField_Readonly('Test', '', '€5.00');
         $result = $field->Field();
 
diff --git a/tests/php/Forms/CurrencyFieldTest.php b/tests/php/Forms/CurrencyFieldTest.php
index 02c4114e4..2ca244dd2 100644
--- a/tests/php/Forms/CurrencyFieldTest.php
+++ b/tests/php/Forms/CurrencyFieldTest.php
@@ -67,7 +67,7 @@ class CurrencyFieldTest extends SapphireTest
         );
 
         //tests with updated currency symbol setting
-        DBCurrency::config()->update('currency_symbol', '€');
+        DBCurrency::config()->set('currency_symbol', '€');
 
         $f->setValue('123.45');
         $this->assertTrue(
@@ -180,7 +180,7 @@ class CurrencyFieldTest extends SapphireTest
         );
 
         //update currency symbol via config
-        DBCurrency::config()->update('currency_symbol', '€');
+        DBCurrency::config()->set('currency_symbol', '€');
 
         $f->setValue('123.45');
         $this->assertEquals(
@@ -263,7 +263,7 @@ class CurrencyFieldTest extends SapphireTest
         );
 
         //tests with updated currency symbol setting
-        DBCurrency::config()->update('currency_symbol', '€');
+        DBCurrency::config()->set('currency_symbol', '€');
 
         $f->setValue('€123.45');
         $this->assertEquals(
@@ -302,11 +302,14 @@ class CurrencyFieldTest extends SapphireTest
         $field = new CurrencyField('Test', '', '$5.00');
         $validator = new RequiredFields();
 
-        DBCurrency::config()->update('currency_symbol', '€');
+        DBCurrency::config()->set('currency_symbol', '€');
         $result = $field->validate($validator);
 
         $this->assertFalse($result, 'Validation should fail since wrong currency was used');
         $this->assertFalse($validator->getResult()->isValid(), 'Validator should receive failed state');
-        $this->assertStringContainsString('Please enter a valid currency', $validator->getResult()->serialize());
+        $this->assertStringContainsString(
+            'Please enter a valid currency',
+            json_encode($validator->getResult()->__serialize())
+        );
     }
 }
diff --git a/tests/php/Forms/FormFieldTest.php b/tests/php/Forms/FormFieldTest.php
index f633e6792..47a3ff946 100644
--- a/tests/php/Forms/FormFieldTest.php
+++ b/tests/php/Forms/FormFieldTest.php
@@ -31,7 +31,7 @@ class FormFieldTest extends SapphireTest
     {
         Config::nest();
 
-        FormField::config()->update(
+        FormField::config()->merge(
             'default_classes',
             [
                 'class1',
@@ -42,7 +42,7 @@ class FormFieldTest extends SapphireTest
 
         $this->assertStringContainsString('class1', $field->extraClass(), 'Class list does not contain expected class');
 
-        FormField::config()->update(
+        FormField::config()->merge(
             'default_classes',
             [
                 'class1',
@@ -54,7 +54,7 @@ class FormFieldTest extends SapphireTest
 
         $this->assertStringContainsString('class1 class2', $field->extraClass(), 'Class list does not contain expected class');
 
-        FormField::config()->update(
+        FormField::config()->merge(
             'default_classes',
             [
                 'class3',
@@ -69,7 +69,7 @@ class FormFieldTest extends SapphireTest
 
         $this->assertStringNotContainsString('class3', $field->extraClass(), 'Class list contains unexpected class');
 
-        TextField::config()->update(
+        TextField::config()->merge(
             'default_classes',
             [
                 'textfield-class',
diff --git a/tests/php/Forms/FormTest.php b/tests/php/Forms/FormTest.php
index 140db87fb..34689f487 100644
--- a/tests/php/Forms/FormTest.php
+++ b/tests/php/Forms/FormTest.php
@@ -792,7 +792,7 @@ class FormTest extends FunctionalTest
 
     public function testDefaultClasses()
     {
-        Form::config()->update(
+        Form::config()->merge(
             'default_classes',
             [
             'class1',
@@ -803,7 +803,7 @@ class FormTest extends FunctionalTest
 
         $this->assertStringContainsString('class1', $form->extraClass(), 'Class list does not contain expected class');
 
-        Form::config()->update(
+        Form::config()->merge(
             'default_classes',
             [
             'class1',
@@ -815,7 +815,7 @@ class FormTest extends FunctionalTest
 
         $this->assertStringContainsString('class1 class2', $form->extraClass(), 'Class list does not contain expected class');
 
-        Form::config()->update(
+        Form::config()->merge(
             'default_classes',
             [
             'class3',
diff --git a/tests/php/Logging/MonologErrorHandlerTest.php b/tests/php/Logging/MonologErrorHandlerTest.php
index 6bbe37b03..b31251e91 100644
--- a/tests/php/Logging/MonologErrorHandlerTest.php
+++ b/tests/php/Logging/MonologErrorHandlerTest.php
@@ -4,6 +4,7 @@ namespace SilverStripe\Logging\Tests;
 
 use InvalidArgumentException;
 use Psr\Log\LoggerInterface;
+use SilverStripe\Dev\Deprecation;
 use SilverStripe\Dev\SapphireTest;
 use SilverStripe\Logging\MonologErrorHandler;
 
@@ -26,8 +27,10 @@ class MonologErrorHandlerTest extends SapphireTest
         $handler->pushLogger($logger)->pushLogger($logger);
         $this->assertCount(2, $handler->getLoggers(), 'Loggers are pushed to the stack');
 
-        $handler->setLogger($logger);
-        $this->assertCount(1, $handler->getLoggers(), 'setLogger resets stack and pushes');
+        if (!Deprecation::isEnabled()) {
+            $handler->setLogger($logger);
+            $this->assertCount(1, $handler->getLoggers(), 'setLogger resets stack and pushes');
+        }
 
         $handler->setLoggers([]);
         $this->assertCount(0, $handler->getLoggers(), 'setLoggers overwrites all configured loggers');
diff --git a/tests/php/ORM/ArrayListTest.php b/tests/php/ORM/ArrayListTest.php
index d2e57447d..9cb606030 100644
--- a/tests/php/ORM/ArrayListTest.php
+++ b/tests/php/ORM/ArrayListTest.php
@@ -133,6 +133,21 @@ class ArrayListTest extends SapphireTest
         );
     }
 
+    public function testLimitNull()
+    {
+        $list = new ArrayList(
+            [
+                ['Key' => 1], ['Key' => 2], ['Key' => 3]
+            ]
+        );
+        $this->assertEquals(
+            $list->limit(null, 0)->toArray(),
+            [
+                ['Key' => 1], ['Key' => 2], ['Key' => 3]
+            ]
+        );
+    }
+
     public function testAddRemove()
     {
         $list = new ArrayList(
diff --git a/tests/php/ORM/DataObjectSchemaGenerationTest.php b/tests/php/ORM/DataObjectSchemaGenerationTest.php
index 95e0aa98a..b8a3d30bc 100644
--- a/tests/php/ORM/DataObjectSchemaGenerationTest.php
+++ b/tests/php/ORM/DataObjectSchemaGenerationTest.php
@@ -101,7 +101,7 @@ class DataObjectSchemaGenerationTest extends SapphireTest
         // Table will have been initially created by the $extraDataObjects setting
 
         // Let's insert a new field here
-        TestObject::config()->update(
+        TestObject::config()->merge(
             'db',
             [
             'SecretField' => 'Varchar(100)'
@@ -170,7 +170,7 @@ class DataObjectSchemaGenerationTest extends SapphireTest
         // Table will have been initially created by the $extraDataObjects setting
 
         // Update the SearchFields index here
-        TestIndexObject::config()->update(
+        TestIndexObject::config()->merge(
             'indexes',
             [
                 'SearchFields' => [
@@ -265,35 +265,35 @@ class DataObjectSchemaGenerationTest extends SapphireTest
             'columns' => ['Sort'],
         ], $indexes);
         DataObject::getSchema()->reset();
-        Config::inst()->update(SortedObject::class, 'default_sort', 'Sort ASC');
+        Config::inst()->set(SortedObject::class, 'default_sort', 'Sort ASC');
         $indexes = DataObject::getSchema()->databaseIndexes(SortedObject::class);
         $this->assertContains([
             'type' => 'index',
             'columns' => ['Sort'],
         ], $indexes);
         DataObject::getSchema()->reset();
-        Config::inst()->update(SortedObject::class, 'default_sort', 'Sort DESC');
+        Config::inst()->set(SortedObject::class, 'default_sort', 'Sort DESC');
         $indexes = DataObject::getSchema()->databaseIndexes(SortedObject::class);
         $this->assertContains([
             'type' => 'index',
             'columns' => ['Sort'],
         ], $indexes);
         DataObject::getSchema()->reset();
-        Config::inst()->update(SortedObject::class, 'default_sort', '"Sort" DESC');
+        Config::inst()->set(SortedObject::class, 'default_sort', '"Sort" DESC');
         $indexes = DataObject::getSchema()->databaseIndexes(SortedObject::class);
         $this->assertContains([
             'type' => 'index',
             'columns' => ['Sort'],
         ], $indexes);
         DataObject::getSchema()->reset();
-        Config::inst()->update(SortedObject::class, 'default_sort', '"DataObjectSchemaGenerationTest_SortedObject"."Sort" ASC');
+        Config::inst()->set(SortedObject::class, 'default_sort', '"DataObjectSchemaGenerationTest_SortedObject"."Sort" ASC');
         $indexes = DataObject::getSchema()->databaseIndexes(SortedObject::class);
         $this->assertContains([
             'type' => 'index',
             'columns' => ['Sort'],
         ], $indexes);
         DataObject::getSchema()->reset();
-        Config::inst()->update(SortedObject::class, 'default_sort', '"Sort" DESC, "Title" ASC');
+        Config::inst()->set(SortedObject::class, 'default_sort', '"Sort" DESC, "Title" ASC');
         $indexes = DataObject::getSchema()->databaseIndexes(SortedObject::class);
         $this->assertContains([
             'type' => 'index',
@@ -305,7 +305,7 @@ class DataObjectSchemaGenerationTest extends SapphireTest
         ], $indexes);
         DataObject::getSchema()->reset();
         // make sure that specific indexes aren't overwritten
-        Config::inst()->update(SortedObject::class, 'indexes', [
+        Config::inst()->merge(SortedObject::class, 'indexes', [
             'Sort' => [
                 'type' => 'unique',
                 'columns' => ['Sort'],
diff --git a/tests/php/ORM/HierarchyCachingTest.php b/tests/php/ORM/HierarchyCachingTest.php
index afbd488c2..8070fbe26 100644
--- a/tests/php/ORM/HierarchyCachingTest.php
+++ b/tests/php/ORM/HierarchyCachingTest.php
@@ -37,7 +37,7 @@ class HierachyCacheTest extends SapphireTest
     public static function setUpBeforeClass(): void
     {
         parent::setUpBeforeClass();
-        HideTestObject::config()->update(
+        HideTestObject::config()->merge(
             'hide_from_hierarchy',
             [ HideTestSubObject::class ]
         );
diff --git a/tests/php/ORM/HierarchyTest.php b/tests/php/ORM/HierarchyTest.php
index 697fc7c2f..c3d2e0b12 100644
--- a/tests/php/ORM/HierarchyTest.php
+++ b/tests/php/ORM/HierarchyTest.php
@@ -273,7 +273,7 @@ class HierarchyTest extends SapphireTest
 
     public function testHideFromHierarchy()
     {
-        HierarchyTest\HideTestObject::config()->update(
+        HierarchyTest\HideTestObject::config()->merge(
             'hide_from_hierarchy',
             [ HierarchyTest\HideTestSubObject::class ]
         );
diff --git a/tests/php/ORM/ManyManyListTest.php b/tests/php/ORM/ManyManyListTest.php
index f7b4dd5b5..2dd852b62 100644
--- a/tests/php/ORM/ManyManyListTest.php
+++ b/tests/php/ORM/ManyManyListTest.php
@@ -423,7 +423,7 @@ class ManyManyListTest extends SapphireTest
         $obj->Clients()->add($obj2, ['Worth' => $money, 'Reference' => 'B']);
 
         // Set the default sort for this relation
-        Config::inst()->update('ManyManyListTest_ExtraFields_Clients', 'default_sort', 'Reference ASC');
+        Config::inst()->set('ManyManyListTest_ExtraFields_Clients', 'default_sort', 'Reference ASC');
         $clients = $obj->Clients();
         $this->assertCount(2, $clients);
 
@@ -432,7 +432,7 @@ class ManyManyListTest extends SapphireTest
         $this->assertEquals('B', $second->Reference);
 
         // Now we ensure the default sort is being respected by reversing its order
-        Config::inst()->update('ManyManyListTest_ExtraFields_Clients', 'default_sort', 'Reference DESC');
+        Config::inst()->set('ManyManyListTest_ExtraFields_Clients', 'default_sort', 'Reference DESC');
         $reverseClients = $obj->Clients();
         $this->assertCount(2, $reverseClients);
 
diff --git a/tests/php/ORM/ManyManyThroughListTest.php b/tests/php/ORM/ManyManyThroughListTest.php
index 2d9cb8908..26211d7c2 100644
--- a/tests/php/ORM/ManyManyThroughListTest.php
+++ b/tests/php/ORM/ManyManyThroughListTest.php
@@ -268,7 +268,7 @@ class ManyManyThroughListTest extends SapphireTest
     {
         $this->expectException(\InvalidArgumentException::class);
         DataObject::reset();
-        ManyManyThroughListTest\Item::config()->update(
+        ManyManyThroughListTest\Item::config()->merge(
             'db',
             [
             ManyManyThroughListTest\JoinObject::class => 'Text'
@@ -416,7 +416,7 @@ class ManyManyThroughListTest extends SapphireTest
         $this->assertSame('International', $second->Title);
 
         // Ensure that we're respecting the default sort by reversing it
-        Config::inst()->update(FallbackLocale::class, 'default_sort', '"ManyManyThroughTest_FallbackLocale"."Sort" DESC');
+        Config::inst()->set(FallbackLocale::class, 'default_sort', '"ManyManyThroughTest_FallbackLocale"."Sort" DESC');
 
         $reverse = $mexico->Fallbacks();
         list($firstReverse, $secondReverse) = $reverse;
diff --git a/tests/php/ORM/MySQLPDOConnectorTest.php b/tests/php/ORM/MySQLPDOConnectorTest.php
index 473d71eb9..7a122c3a0 100644
--- a/tests/php/ORM/MySQLPDOConnectorTest.php
+++ b/tests/php/ORM/MySQLPDOConnectorTest.php
@@ -10,6 +10,7 @@ use SilverStripe\Dev\TestOnly;
 use SilverStripe\ORM\Tests\MySQLPDOConnectorTest\PDOConnector;
 use SilverStripe\ORM\DB;
 use SilverStripe\Tests\ORM\Utf8\Utf8TestHelper;
+use SilverStripe\Dev\Deprecation;
 
 /**
  * @requires extension PDO
@@ -22,6 +23,9 @@ class MySQLPDOConnectorTest extends SapphireTest implements TestOnly
      */
     public function testConnectionCharsetControl($charset, $defaultCollation)
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
         $config = DB::getConfig();
         $config['driver'] = 'mysql';
         $config['charset'] = $charset;
@@ -51,6 +55,9 @@ class MySQLPDOConnectorTest extends SapphireTest implements TestOnly
      */
     public function testConnectionCollationControl($charset, $defaultCollation, $customCollation)
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
         $config = DB::getConfig();
         $config['charset'] = $charset;
         $config['driver'] = 'mysql';
@@ -86,6 +93,9 @@ class MySQLPDOConnectorTest extends SapphireTest implements TestOnly
 
     public function testUtf8mb4GeneralCollation()
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
         $charset = 'utf8mb4';
         $collation = 'utf8mb4_general_ci';
 
@@ -113,6 +123,9 @@ class MySQLPDOConnectorTest extends SapphireTest implements TestOnly
 
     public function testUtf8mb4UnicodeCollation()
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
         $charset = 'utf8mb4';
         $collation = 'utf8mb4_unicode_ci';
 
diff --git a/tests/php/ORM/SQLSelectTest.php b/tests/php/ORM/SQLSelectTest.php
index f3618ebe0..54b29209a 100755
--- a/tests/php/ORM/SQLSelectTest.php
+++ b/tests/php/ORM/SQLSelectTest.php
@@ -8,7 +8,6 @@ use SilverStripe\ORM\Connect\MySQLDatabase;
 use SilverStripe\ORM\Queries\SQLSelect;
 use SilverStripe\SQLite\SQLite3Database;
 use SilverStripe\PostgreSQL\PostgreSQLDatabase;
-use SilverStripe\Dev\Deprecation;
 use SilverStripe\Dev\SapphireTest;
 
 class SQLSelectTest extends SapphireTest
@@ -24,18 +23,6 @@ class SQLSelectTest extends SapphireTest
 
     protected $oldDeprecation = null;
 
-    protected function setUp(): void
-    {
-        parent::setUp();
-        $this->oldDeprecation = Deprecation::dump_settings();
-    }
-
-    protected function tearDown(): void
-    {
-        Deprecation::restore_settings($this->oldDeprecation);
-        parent::tearDown();
-    }
-
     public function testCount()
     {
 
diff --git a/tests/php/ORM/TransactionTest.php b/tests/php/ORM/TransactionTest.php
index 8c524e78c..6a27bdc69 100644
--- a/tests/php/ORM/TransactionTest.php
+++ b/tests/php/ORM/TransactionTest.php
@@ -5,7 +5,6 @@ namespace SilverStripe\ORM\Tests;
 use SilverStripe\ORM\DB;
 use SilverStripe\ORM\DataObject;
 use SilverStripe\Dev\SapphireTest;
-use SilverStripe\Dev\Deprecation;
 use SilverStripe\ORM\Tests\TransactionTest\TestObject;
 
 class TransactionTest extends SapphireTest
@@ -20,18 +19,6 @@ class TransactionTest extends SapphireTest
 
     private static $originalVersionInfo;
 
-    protected function setUp(): void
-    {
-        parent::setUp();
-        self::$originalVersionInfo = Deprecation::dump_settings();
-    }
-
-    protected function tearDown(): void
-    {
-        Deprecation::restore_settings(self::$originalVersionInfo);
-        parent::tearDown();
-    }
-
     public static function setUpBeforeClass(): void
     {
         parent::setUpBeforeClass();
@@ -166,9 +153,6 @@ class TransactionTest extends SapphireTest
             return;
         }
 
-        // This feature is deprecated in 4.4, but we're still testing it.
-        Deprecation::notification_version('4.3.0');
-
         $page = new TestObject();
         $page->Title = 'Read only success';
         $page->write();
diff --git a/tests/php/Security/MemberAuthenticator/SessionAuthenticationHandlerTest.php b/tests/php/Security/MemberAuthenticator/SessionAuthenticationHandlerTest.php
index def203040..87276e3e5 100644
--- a/tests/php/Security/MemberAuthenticator/SessionAuthenticationHandlerTest.php
+++ b/tests/php/Security/MemberAuthenticator/SessionAuthenticationHandlerTest.php
@@ -15,10 +15,6 @@ class SessionAuthenticationHandlerTest extends SapphireTest
 
     protected $usesDatabase = true;
 
-    /**
-     * @runInSeparateProcess
-     * @preserveGlobalState disabled
-     */
     public function testAuthenticateRequestDefersSessionStartWithoutSessionIdentifier()
     {
         $member = new Member(['Email' => 'test@example.com']);
@@ -36,10 +32,6 @@ class SessionAuthenticationHandlerTest extends SapphireTest
         $this->assertNull($matchedMember);
     }
 
-    /**
-     * @runInSeparateProcess
-     * @preserveGlobalState disabled
-     */
     public function testAuthenticateRequestStartsSessionWithSessionIdentifier()
     {
         $member = new Member(['Email' => 'test@example.com']);
@@ -49,12 +41,13 @@ class SessionAuthenticationHandlerTest extends SapphireTest
 
         $session = new Session(null); // unstarted
         $session->set($handler->getSessionVariable(), $member->ID);
+        $session = new Session($session); // started
 
         $req = new HTTPRequest('GET', '/');
         $req->setSession($session);
 
+        // simulate detection of session cookie
         Cookie::set(session_name(), '1234');
-        $session->start($req); // simulate detection of session cookie
 
         $matchedMember = $handler->authenticateRequest($req);
         $this->assertNotNull($matchedMember);
diff --git a/tests/php/Security/MemberCsvBulkLoaderTest.php b/tests/php/Security/MemberCsvBulkLoaderTest.php
index 0b3d18363..723adcd46 100644
--- a/tests/php/Security/MemberCsvBulkLoaderTest.php
+++ b/tests/php/Security/MemberCsvBulkLoaderTest.php
@@ -9,6 +9,7 @@ use SilverStripe\Security\Member;
 use SilverStripe\Security\PasswordValidator;
 use SilverStripe\Security\Security;
 use SilverStripe\Dev\SapphireTest;
+use SilverStripe\Security\MemberAuthenticator\MemberAuthenticator;
 
 class MemberCsvBulkLoaderTest extends SapphireTest
 {
@@ -105,7 +106,8 @@ class MemberCsvBulkLoaderTest extends SapphireTest
 
         // TODO Direct getter doesn't work, wtf!
         $this->assertEquals(Security::config()->password_encryption_algorithm, $member->getField('PasswordEncryption'));
-        $result = $member->checkPassword('mypassword');
+        $auth = new MemberAuthenticator();
+        $result = $auth->checkPassword($member, 'mypassword');
         $this->assertTrue($result->isValid());
     }
 }
diff --git a/tests/php/Security/MemberTest.php b/tests/php/Security/MemberTest.php
index 62454b56d..53e1875b4 100644
--- a/tests/php/Security/MemberTest.php
+++ b/tests/php/Security/MemberTest.php
@@ -219,7 +219,7 @@ class MemberTest extends FunctionalTest
      */
     public function testChangedPasswordEmaling()
     {
-        Member::config()->update('notify_password_change', true);
+        Member::config()->set('notify_password_change', true);
 
         $this->clearEmails();
 
@@ -1187,7 +1187,7 @@ class MemberTest extends FunctionalTest
         $this->assertStringContainsString($message, $response->getBody());
 
         // Logging out from the second device - only one device being logged out
-        RememberLoginHash::config()->update('logout_across_devices', false);
+        RememberLoginHash::config()->set('logout_across_devices', false);
         $this->get(
             'Security/logout',
             $this->session(),
@@ -1205,7 +1205,7 @@ class MemberTest extends FunctionalTest
         // If session-manager module is installed then logout_across_devices is modified so skip
         if (!class_exists(LoginSession::class)) {
             // Logging out from any device when all login hashes should be removed
-            RememberLoginHash::config()->update('logout_across_devices', true);
+            RememberLoginHash::config()->set('logout_across_devices', true);
             Injector::inst()->get(IdentityStore::class)->logIn($m1, true);
             $this->get('Security/logout', $this->session());
             $this->assertEquals(
@@ -1248,7 +1248,7 @@ class MemberTest extends FunctionalTest
     {
         $maxFailedLoginsAllowed = 3;
         //set up the config variables to enable login lockouts
-        Member::config()->update('lock_out_after_incorrect_logins', $maxFailedLoginsAllowed);
+        Member::config()->set('lock_out_after_incorrect_logins', $maxFailedLoginsAllowed);
 
         /** @var Member $member */
         $member = $this->objFromFixture(Member::class, 'test');
@@ -1282,7 +1282,7 @@ class MemberTest extends FunctionalTest
     public function testMemberValidator()
     {
         // clear custom requirements for this test
-        Member_Validator::config()->update('customRequired', null);
+        Member_Validator::config()->set('customRequired', null);
         /** @var Member $memberA */
         $memberA = $this->objFromFixture(Member::class, 'admin');
         /** @var Member $memberB */
@@ -1358,7 +1358,7 @@ class MemberTest extends FunctionalTest
     public function testMemberValidatorWithExtensions()
     {
         // clear custom requirements for this test
-        Member_Validator::config()->update('customRequired', null);
+        Member_Validator::config()->set('customRequired', null);
 
         // create a blank form
         $form = new MemberTest\ValidatorForm();
@@ -1422,7 +1422,7 @@ class MemberTest extends FunctionalTest
     public function testCustomMemberValidator()
     {
         // clear custom requirements for this test
-        Member_Validator::config()->update('customRequired', null);
+        Member_Validator::config()->set('customRequired', null);
 
         $member = $this->objFromFixture(Member::class, 'admin');
 
diff --git a/tests/php/Security/RandomGeneratorTest.php b/tests/php/Security/RandomGeneratorTest.php
index 3d2048e94..6f7d2dea1 100644
--- a/tests/php/Security/RandomGeneratorTest.php
+++ b/tests/php/Security/RandomGeneratorTest.php
@@ -3,6 +3,7 @@
 namespace SilverStripe\Security\Tests;
 
 use SilverStripe\Security\RandomGenerator;
+use SilverStripe\Dev\Deprecation;
 use SilverStripe\Dev\SapphireTest;
 
 /**
@@ -13,6 +14,9 @@ class RandomGeneratorTest extends SapphireTest
 
     public function testGenerateEntropy()
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
         $r = new RandomGenerator();
         $this->assertNotNull($r->generateEntropy());
         $this->assertNotEquals($r->generateEntropy(), $r->generateEntropy());
diff --git a/tests/php/View/ArrayDataTest.php b/tests/php/View/ArrayDataTest.php
index b90258f79..49d93309e 100644
--- a/tests/php/View/ArrayDataTest.php
+++ b/tests/php/View/ArrayDataTest.php
@@ -4,7 +4,6 @@ namespace SilverStripe\View\Tests;
 
 use SilverStripe\ORM\ArrayLib;
 use SilverStripe\ORM\FieldType\DBVarchar;
-use SilverStripe\Dev\Deprecation;
 use SilverStripe\Dev\SapphireTest;
 use SilverStripe\View\ArrayData;
 use stdClass;
@@ -67,9 +66,6 @@ class ArrayDataTest extends SapphireTest
 
     public function testGetArray()
     {
-        $originalDeprecation = Deprecation::dump_settings();
-        Deprecation::notification_version('2.4');
-
         $array = [
             'Foo' => 'Foo',
             'Bar' => 'Bar',
@@ -79,8 +75,6 @@ class ArrayDataTest extends SapphireTest
         $arrayData = new ArrayData($array);
 
         $this->assertEquals($arrayData->toMap(), $array);
-
-        Deprecation::restore_settings($originalDeprecation);
     }
 
     public function testArrayToObject()
diff --git a/tests/php/View/RequirementsTest.php b/tests/php/View/RequirementsTest.php
index 69144ea5b..ae9d19558 100644
--- a/tests/php/View/RequirementsTest.php
+++ b/tests/php/View/RequirementsTest.php
@@ -516,7 +516,7 @@ class RequirementsTest extends SapphireTest
         $combinedFileName = '/_combinedfiles/RequirementsTest_bc-2a55d56.js';
         $combinedFilePath = TestAssetStore::base_path() . $combinedFileName;
 
-        $html = $backend->includeInHTML(false, self::$html_template);
+        $html = $backend->includeInHTML(self::$html_template);
 
         /* ASYNC IS INCLUDED IN SCRIPT TAG */
         $this->assertMatchesRegularExpression(
diff --git a/tests/php/View/SSViewerTest.php b/tests/php/View/SSViewerTest.php
index cd1fe076c..ac3779942 100644
--- a/tests/php/View/SSViewerTest.php
+++ b/tests/php/View/SSViewerTest.php
@@ -32,6 +32,7 @@ use SilverStripe\View\SSViewer_FromString;
 use SilverStripe\View\Tests\SSViewerTest\SSViewerTestModel;
 use SilverStripe\View\Tests\SSViewerTest\SSViewerTestModelController;
 use SilverStripe\View\ViewableData;
+use SilverStripe\Dev\Deprecation;
 
 /**
  * @skipUpgrade
@@ -53,8 +54,8 @@ class SSViewerTest extends SapphireTest
     protected function setUp(): void
     {
         parent::setUp();
-        SSViewer::config()->update('source_file_comments', false);
-        SSViewer_FromString::config()->update('cache_template', false);
+        SSViewer::config()->set('source_file_comments', false);
+        SSViewer_FromString::config()->set('cache_template', false);
         TestAssetStore::activate('SSViewerTest');
         $this->oldServer = $_SERVER;
     }
@@ -73,7 +74,10 @@ class SSViewerTest extends SapphireTest
      */
     public function testCurrentTheme()
     {
-        SSViewer::config()->update('theme', 'mytheme');
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
+        SSViewer::config()->set('theme', 'mytheme');
         $this->assertEquals(
             'mytheme',
             SSViewer::config()->uninherited('theme'),
@@ -1269,39 +1273,39 @@ after'
         $this->assertEquals("12345678910", $result, "Numbers rendered in order");
 
         //test First
-        $result = $this->render('<% loop Set %><% if First %>$Number<% end_if %><% end_loop %>', $data);
+        $result = $this->render('<% loop Set %><% if $IsFirst %>$Number<% end_if %><% end_loop %>', $data);
         $this->assertEquals("1", $result, "Only the first number is rendered");
 
         //test Last
-        $result = $this->render('<% loop Set %><% if Last %>$Number<% end_if %><% end_loop %>', $data);
+        $result = $this->render('<% loop Set %><% if $IsLast %>$Number<% end_if %><% end_loop %>', $data);
         $this->assertEquals("10", $result, "Only the last number is rendered");
 
         //test Even
-        $result = $this->render('<% loop Set %><% if Even() %>$Number<% end_if %><% end_loop %>', $data);
+        $result = $this->render('<% loop Set %><% if $Even() %>$Number<% end_if %><% end_loop %>', $data);
         $this->assertEquals("246810", $result, "Even numbers rendered in order");
 
         //test Even with quotes
-        $result = $this->render('<% loop Set %><% if Even("1") %>$Number<% end_if %><% end_loop %>', $data);
+        $result = $this->render('<% loop Set %><% if $Even("1") %>$Number<% end_if %><% end_loop %>', $data);
         $this->assertEquals("246810", $result, "Even numbers rendered in order");
 
         //test Even without quotes
-        $result = $this->render('<% loop Set %><% if Even(1) %>$Number<% end_if %><% end_loop %>', $data);
+        $result = $this->render('<% loop Set %><% if $Even(1) %>$Number<% end_if %><% end_loop %>', $data);
         $this->assertEquals("246810", $result, "Even numbers rendered in order");
 
         //test Even with zero-based start index
-        $result = $this->render('<% loop Set %><% if Even("0") %>$Number<% end_if %><% end_loop %>', $data);
+        $result = $this->render('<% loop Set %><% if $Even("0") %>$Number<% end_if %><% end_loop %>', $data);
         $this->assertEquals("13579", $result, "Even (with zero-based index) numbers rendered in order");
 
         //test Odd
-        $result = $this->render('<% loop Set %><% if Odd %>$Number<% end_if %><% end_loop %>', $data);
+        $result = $this->render('<% loop Set %><% if $Odd %>$Number<% end_if %><% end_loop %>', $data);
         $this->assertEquals("13579", $result, "Odd numbers rendered in order");
 
         //test FirstLast
-        $result = $this->render('<% loop Set %><% if FirstLast %>$Number$FirstLast<% end_if %><% end_loop %>', $data);
+        $result = $this->render('<% loop Set %><% if $FirstLast %>$Number$FirstLast<% end_if %><% end_loop %>', $data);
         $this->assertEquals("1first10last", $result, "First and last numbers rendered in order");
 
         //test Middle
-        $result = $this->render('<% loop Set %><% if Middle %>$Number<% end_if %><% end_loop %>', $data);
+        $result = $this->render('<% loop Set %><% if $Middle %>$Number<% end_if %><% end_loop %>', $data);
         $this->assertEquals("23456789", $result, "Middle numbers rendered in order");
 
         //test MiddleString
@@ -1611,7 +1615,7 @@ after'
         $this->assertEqualIgnoringWhitespace(
             '1ab23last',
             $this->render(
-                '<% loop $Foo %>$Name<% loop Children %>$Name<% end_loop %><% if Last %>last<% end_if %>'
+                '<% loop $Foo %>$Name<% loop Children %>$Name<% end_loop %><% if $IsLast %>last<% end_if %>'
                 . '<% end_loop %>',
                 $data
             )
@@ -1819,7 +1823,7 @@ EOC;
 
     public function testRenderWithSourceFileComments()
     {
-        SSViewer::config()->update('source_file_comments', true);
+        SSViewer::config()->set('source_file_comments', true);
         $i = __DIR__ . '/SSViewerTest/templates/Includes';
         $f = __DIR__ . '/SSViewerTest/templates/SSViewerTestComments';
         $templates = [
@@ -2099,7 +2103,7 @@ EOC;
         $this->render($content, null, null);
         $this->assertFalse(file_exists($cacheFile ?? ''), 'Cache file was created when caching was off');
 
-        SSViewer_FromString::config()->update('cache_template', true);
+        SSViewer_FromString::config()->set('cache_template', true);
         $this->render($content, null, null);
         $this->assertTrue(file_exists($cacheFile ?? ''), 'Cache file wasn\'t created when it was meant to');
         unlink($cacheFile ?? '');
diff --git a/tests/php/View/SSViewerTest/templates/Includes/SSViewerTestIncludeScopeInheritanceInclude.ss b/tests/php/View/SSViewerTest/templates/Includes/SSViewerTestIncludeScopeInheritanceInclude.ss
index 0a67cba95..bd92206e7 100644
--- a/tests/php/View/SSViewerTest/templates/Includes/SSViewerTestIncludeScopeInheritanceInclude.ss
+++ b/tests/php/View/SSViewerTest/templates/Includes/SSViewerTestIncludeScopeInheritanceInclude.ss
@@ -1 +1 @@
-<% if $Title %>$Title<% else %>Untitled<% end_if %> <% if $ArgA %>_ $ArgA <% end_if %>- <% if $First %>First-<% end_if %><% if $Last %>Last-<% end_if %><%if $MultipleOf(2) %>EVEN<% else %>ODD<% end_if %> top:$Top.Title
+<% if $Title %>$Title<% else %>Untitled<% end_if %> <% if $ArgA %>_ $ArgA <% end_if %>- <% if $IsFirst %>First-<% end_if %><% if $IsLast %>Last-<% end_if %><%if $MultipleOf(2) %>EVEN<% else %>ODD<% end_if %> top:$Top.Title
diff --git a/tests/php/View/SSViewerTest/templates/Includes/SSViewerTestIncludeScopeInheritanceWithArgsInLoop.ss b/tests/php/View/SSViewerTest/templates/Includes/SSViewerTestIncludeScopeInheritanceWithArgsInLoop.ss
index 44479e5ea..32dd1fccf 100644
--- a/tests/php/View/SSViewerTest/templates/Includes/SSViewerTestIncludeScopeInheritanceWithArgsInLoop.ss
+++ b/tests/php/View/SSViewerTest/templates/Includes/SSViewerTestIncludeScopeInheritanceWithArgsInLoop.ss
@@ -1 +1 @@
-$Title - <% loop $Items %>$Title<% if not Last %> - <% else %> - {$Top.Title}<% end_if %><% end_loop %>
\ No newline at end of file
+$Title - <% loop $Items %>$Title<% if not $IsLast %> - <% else %> - {$Top.Title}<% end_if %><% end_loop %>
\ No newline at end of file
diff --git a/tests/php/View/ViewableDataTest.php b/tests/php/View/ViewableDataTest.php
index 3f3e7b329..f3c776aaa 100644
--- a/tests/php/View/ViewableDataTest.php
+++ b/tests/php/View/ViewableDataTest.php
@@ -7,6 +7,7 @@ use SilverStripe\Dev\SapphireTest;
 use SilverStripe\View\ArrayData;
 use SilverStripe\View\SSViewer;
 use SilverStripe\View\ViewableData;
+use SilverStripe\Dev\Deprecation;
 
 /**
  * See {@link SSViewerTest->testCastingHelpers()} for more tests related to casting and ViewableData behaviour,
@@ -208,6 +209,9 @@ class ViewableDataTest extends SapphireTest
 
     public function testThemeDir()
     {
+        if (Deprecation::isEnabled()) {
+            $this->markTestSkipped('Test calls deprecated code');
+        }
         $themes = [
             "silverstripe/framework:/tests/php/View/ViewableDataTest/testtheme",
             SSViewer::DEFAULT_THEME
diff --git a/tests/php/i18n/i18nTest.php b/tests/php/i18n/i18nTest.php
index 08065a543..79882c940 100644
--- a/tests/php/i18n/i18nTest.php
+++ b/tests/php/i18n/i18nTest.php
@@ -149,7 +149,7 @@ class i18nTest extends SapphireTest
     public function testTemplateTranslation()
     {
         $oldLocale = i18n::get_locale();
-        i18n::config()->update('missing_default_warning', false);
+        i18n::config()->set('missing_default_warning', false);
 
         /** @var SymfonyMessageProvider $provider */
         $provider = Injector::inst()->get(MessageProvider::class);
@@ -311,7 +311,7 @@ class i18nTest extends SapphireTest
      * */
     public function testNewTemplateTranslation()
     {
-        i18n::config()->update('missing_default_warning', false);
+        i18n::config()->set('missing_default_warning', false);
 
         /** @var SymfonyMessageProvider $provider */
         $provider = Injector::inst()->get(MessageProvider::class);
@@ -468,7 +468,7 @@ class i18nTest extends SapphireTest
 
     public function testGetLanguageName()
     {
-        i18n::config()->update(
+        i18n::config()->merge(
             'common_languages',
             ['de_CGN' => ['name' => 'German (Cologne)', 'native' => 'K&ouml;lsch']]
         );
diff --git a/tests/php/i18n/i18nTestManifest.php b/tests/php/i18n/i18nTestManifest.php
index 3a06f06ce..b08c91a54 100644
--- a/tests/php/i18n/i18nTestManifest.php
+++ b/tests/php/i18n/i18nTestManifest.php
@@ -82,7 +82,7 @@ trait i18nTestManifest
         // Switch to test manifest
         $s = DIRECTORY_SEPARATOR;
         $this->alternateBasePath = __DIR__ . $s . 'i18nTest' . $s . "_fakewebroot";
-        Director::config()->update('alternate_base_folder', $this->alternateBasePath);
+        Director::config()->set('alternate_base_folder', $this->alternateBasePath);
 
         // New module manifest
         $moduleManifest = new ModuleManifest($this->alternateBasePath);
diff --git a/tests/php/i18n/i18nTextCollectorTest.php b/tests/php/i18n/i18nTextCollectorTest.php
index 6812c9cc6..c79bdddaa 100644
--- a/tests/php/i18n/i18nTextCollectorTest.php
+++ b/tests/php/i18n/i18nTextCollectorTest.php
@@ -533,8 +533,8 @@ PHP;
     public function testCollectFromFilesystemAndWriteMasterTables()
     {
         i18n::set_locale('en_US');  //set the locale to the US locale expected in the asserts
-        i18n::config()->update('default_locale', 'en_US');
-        i18n::config()->update('missing_default_warning', false);
+        i18n::config()->set('default_locale', 'en_US');
+        i18n::config()->set('missing_default_warning', false);
 
         $c = i18nTextCollector::create();
         $c->setWarnOnEmptyDefault(false);