MNT PHP8 support

.travis.yml

@@ -31,7 +31,7 @@ matrix:
   fast_finish: true
   include:
     - php: 7.1
-      env: DB=MYSQL RECIPE_VERSION=4.x-dev PHPUNIT_TEST=1 PHPCS_TEST=1 PDO=1
+      env: DB=MYSQL RECIPE_VERSION=4.x-dev PHPUNIT_TEST=1 PHPCS_TEST=1 PDO=1 COMPOSER_ARG=--prefer-lowest
     - php: 7.2
       env: DB=PGSQL RECIPE_VERSION=4.x-dev PHPUNIT_COVERAGE_TEST=1
     - php: 7.3
@@ -40,6 +40,8 @@ matrix:
       env: DB=MYSQL RECIPE_VERSION=4.x-dev PHPUNIT_TEST=1 NPM_TEST=1
     - php: 7.4
       env: DB=MYSQL RECIPE_VERSION=4.x-dev PHPUNIT_TEST=1
+    - php: nightly
+      env: DB=MYSQL RECIPE_VERSION=4.x-dev PHPUNIT_TEST=1 COMPOSER_ARG=--ignore-platform-reqs WITH_XDEBUG=1
 
 before_script:
 # Extra $PATH
@@ -47,7 +49,7 @@ before_script:
 
 # Init PHP
   - phpenv rehash
-  - phpenv config-rm xdebug.ini
+  - if [[ ! $WITH_XDEBUG ]] ; then phpenv config-rm xdebug.ini; fi
   - export PATH=~/.composer/vendor/bin:$PATH
   - echo 'memory_limit = 2G' >> ~/.phpenv/versions/$(phpenv version-name)/etc/conf.d/travis.ini
 
@@ -57,7 +59,7 @@ before_script:
   # Fix for running phpunit 5 on php 7.4+
   - composer require --no-update sminnee/phpunit-mock-objects:^3
   - if [[ $DB == PGSQL ]]; then composer require --no-update silverstripe/postgresql:^2; fi
-  - composer install --prefer-source --no-interaction --no-progress --no-suggest --optimize-autoloader --verbose --profile
+  - composer update --prefer-source --no-interaction --no-progress --no-suggest --optimize-autoloader --verbose --profile $COMPOSER_ARG
 
 # Install NPM dependencies
   - if [[ $NPM_TEST ]]; then nvm install $TRAVIS_NODE_VERSION && nvm use $TRAVIS_NODE_VERSION && npm install -g yarn && yarn install --network-concurrency 1 && yarn run build; fi

composer.json

@@ -25,10 +25,11 @@
         "silverstripe/reports": "^4.7@dev",
         "silverstripe/siteconfig": "^4.7@dev",
         "silverstripe/versioned": "^1.7@dev",
-        "silverstripe/vendor-plugin": "^1.0"
+        "silverstripe/vendor-plugin": "^1.0",
+        "php": "^7.1 || ^8"
     },
     "require-dev": {
-        "phpunit/phpunit": "^5.7"
+        "sminnee/phpunit": "^5.7"
     },
     "extra": {
         "expose": [