From 25759ffc5fe532a239b1487ca6b025140d2e144f Mon Sep 17 00:00:00 2001
From: Ingo Schommer <me@chillu.com>
Date: Thu, 27 Sep 2018 17:28:56 +1200
Subject: [PATCH] NEW Show file path on PHP parser exceptions

---
 src/Core/Manifest/ClassManifest.php           |  7 ++--
 .../Manifest/ClassManifestErrorHandler.php    | 33 +++++++++++++++++++
 .../ClassManifestErrorHandlerTest.php         | 20 +++++++++++
 3 files changed, 58 insertions(+), 2 deletions(-)
 create mode 100644 src/Core/Manifest/ClassManifestErrorHandler.php
 create mode 100644 src/Core/Manifest/ClassManifestErrorHandlerTest.php

diff --git a/src/Core/Manifest/ClassManifest.php b/src/Core/Manifest/ClassManifest.php
index 9b64c8c4c..23bdc4d52 100644
--- a/src/Core/Manifest/ClassManifest.php
+++ b/src/Core/Manifest/ClassManifest.php
@@ -8,6 +8,7 @@ use PhpParser\NodeTraverser;
 use PhpParser\NodeVisitor\NameResolver;
 use PhpParser\Parser;
 use PhpParser\ParserFactory;
+use PhpParser\ErrorHandler\ErrorHandler;
 use Psr\SimpleCache\CacheInterface;
 use SilverStripe\Core\Cache\CacheFactory;
 use SilverStripe\Dev\TestOnly;
@@ -490,11 +491,13 @@ class ClassManifest
             $changed = true;
             // Build from php file parser
             $fileContents = ClassContentRemover::remove_class_content($pathname);
+            // Not injectable, error handling is an implementation detail.
+            $errorHandler = new ClassManifestErrorHandler($pathname);
             try {
-                $stmts = $this->getParser()->parse($fileContents);
+                $stmts = $this->getParser()->parse($fileContents, $errorHandler);
             } catch (Error $e) {
                 // if our mangled contents breaks, try again with the proper file contents
-                $stmts = $this->getParser()->parse(file_get_contents($pathname));
+                $stmts = $this->getParser()->parse(file_get_contents($pathname), $errorHandler);
             }
             $this->getTraverser()->traverse($stmts);
 
diff --git a/src/Core/Manifest/ClassManifestErrorHandler.php b/src/Core/Manifest/ClassManifestErrorHandler.php
new file mode 100644
index 000000000..b5faf50da
--- /dev/null
+++ b/src/Core/Manifest/ClassManifestErrorHandler.php
@@ -0,0 +1,33 @@
+<?php
+namespace SilverStripe\Core\Manifest;
+
+use PhpParser\Error;
+use PhpParser\ErrorHandler;
+
+/**
+
+ * Error handler which throws, but retains the original path context.
+ * For parsing errors, this is essential information to identify the issue.
+ */
+class ClassManifestErrorHandler implements ErrorHandler
+{
+    /**
+     * @var String
+     */
+    protected $pathname;
+
+    /**
+     * @param String $pathname
+     */
+    public function __construct($pathname)
+    {
+        $this->pathname = $pathname;
+    }
+
+    public function handleError(Error $error)
+    {
+        $newMessage = sprintf('%s in %s', $error->getRawMessage(), $this->pathname);
+        $error->setRawMessage($newMessage);
+        throw $error;
+    }
+}
diff --git a/src/Core/Manifest/ClassManifestErrorHandlerTest.php b/src/Core/Manifest/ClassManifestErrorHandlerTest.php
new file mode 100644
index 000000000..0a9ec22a5
--- /dev/null
+++ b/src/Core/Manifest/ClassManifestErrorHandlerTest.php
@@ -0,0 +1,20 @@
+<?php
+namespace SilverStripe\Core\Tests\Manifest;
+
+use SilverStripe\Dev\SapphireTest;
+use SilverStripe\Core\Manifest\ClassManifestErrorHandler;
+use PhpParser\Error;
+
+class ClassManifestErrorHandlerTest extends SapphireTest
+{
+    /**
+     * @expectedException \PhpParser\Error
+     * @expectedExceptionMessage my error in /my/path
+     */
+    public function testIncludesPathname()
+    {
+        $h = new ClassManifestErrorHandler('/my/path');
+        $e = new Error('my error');
+        $h->handleError($e);
+    }
+}