Make it possible to run tests in PHP 8 (#1760)

* Add npm command to run tests in wp-env

* Add a base env:tests-cmd script

* Run composer install before running tests

* Upgrade phpunit to 8.5 (latest 8.* minor release)

* Void return type must now be specified in certain test methods

See 'Return Type of Template Methods' at https://phpunit.de/announcements/phpunit-8.html

* Remove calls to deprecated assertInternalType()

See sebastianbergmann/phpunit#3368

* Don't generate test cache file

* Don't use depreacated canonicalize parameter of assertEquals()

* Using assertContains() with string haystacks is deprecated

* Upgrade phpunit to 9.6 (latest 9.* minor release)

* assertObjectHasAttribute() is deprecated in favour of assertObjectHasProperty()

* assertRegExp() is deprecated in favour of assertMatchesRegularExpression()

* Remove commented out code

* Only run tests against nightly once

* In GitHub actions, test under PHP 8.3 instead of 7.4

* Document jobs

* In GitHub actions, also test under PHP 7.4

* Add some PHPUnit workflows with PHP 7.4

* Expand GitHub workflows matrix, instead of specifying each job

---------

Co-authored-by: Jesús Amieiro Becerra <1667814+amieiro@users.noreply.github.com>

.github/workflows/phpunit.yml

@@ -37,27 +37,19 @@ jobs:
       fail-fast: false
       matrix:
         os: [ ubuntu-latest ]
-        php: [ '7.4' ]
+        php: [ '7.4', '8.3' ]
         wordpress: [ 'latest', 'nightly' ]
-        multisite: [ false ]
+        multisite: [ false, true ]
         coverage: [ false ]
         experimental: [ false ]
         include:
-        # - php: '8.0'
-        #   os: ubuntu-latest
-        #   experimental: true
+          # Run coverage only on latest PHP.
           - os: ubuntu-latest
-            php: '7.4'
+            php: '8.3'
             wordpress: 'latest'
             multisite: false
             coverage: true
             experimental: false
-          - os: ubuntu-latest
-            php: '7.4'
-            wordpress: 'latest'
-            multisite: true
-            coverage: false
-            experimental: false
 
     steps:
       - name: Check out Git repository

composer.json

@@ -22,7 +22,7 @@
     "dealerdirect/phpcodesniffer-composer-installer": "^1.0.0",
     "gettext/languages": "^2.6",
     "phpcompatibility/phpcompatibility-wp": "^2.1",
-    "phpunit/phpunit": "^7",
+    "phpunit/phpunit": "^9.6.15",
     "wp-coding-standards/wpcs": "^2.2",
     "yoast/phpunit-polyfills": "^2.0"
   },