Add a PHPCompat workflow

.github/workflows/php-compat.yml

@@ -0,0 +1,44 @@
+name: PHP Compatibility
+
+on:
+  push:
+    branches:
+      - develop
+      - trunk
+    paths:
+      - "**.php"
+  pull_request:
+    branches:
+      - develop
+    paths:
+      - "**.php"
+
+jobs:
+  php-compatibility:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Setup proper PHP version
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: 7.4
+
+      - name: Get composer cache directory
+        id: composer-cache
+        run: echo "dir=$(composer config cache-files-dir)" >> $GITHUB_OUTPUT
+
+      - name: Cache dependencies
+        uses: actions/cache@v4
+        with:
+          path: ${{ steps.composer-cache.outputs.dir }}
+          key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
+
+      - name: Install dependencies
+        run: composer install --prefer-dist
+
+      - name: Run PHP Compatibility
+        run: ./vendor/bin/phpcs --standard=./phpcs-compat.xml.dist -p .

composer.json

@@ -34,7 +34,8 @@
     "php-stubs/wp-cli-stubs": "dev-master",
     "johnbillion/wp-compat": "dev-trunk",
     "phpstan/phpstan-deprecation-rules": "1.2.x-dev",
-    "sirbrillig/phpcs-changed": "^2.11"
+    "sirbrillig/phpcs-changed": "^2.11",
+    "phpcompatibility/php-compatibility": "dev-develop as 9.99.99"
   },
   "scripts": {
     "lint": "phpcs -s . --runtime-set testVersion 7.4-",

phpcs-compat.xml.dist

@@ -0,0 +1,18 @@
+<?xml version="1.0"?>
+<ruleset name="PHPCompatibilityWP">
+	<description>PHP Compatibility checks only</description>
+
+	<!-- Files to check -->
+	<arg name="extensions" value="php"/>
+	<file>.</file>
+
+	<rule ref="PHPCompatibilityWP" />
+
+	<exclude-pattern>*/dist/*</exclude-pattern>
+	<exclude-pattern>*/tests/*</exclude-pattern>
+	<exclude-pattern>*/node_modules/*</exclude-pattern>
+	<exclude-pattern>*/vendor/*</exclude-pattern>
+
+	<config name="minimum_supported_wp_version" value="6.1"/>
+	<config name="testVersion" value="7.4-"/>
+</ruleset>