Add a PHPStan configuration and run it as a GitHub Action

.gitattributes

@@ -36,6 +36,7 @@ LICENSE.md export-ignore
 package-lock.json export-ignore
 package.json export-ignore
 phpcs.xml.dist export-ignore
+phpstan.neon.dist export-ignore
 phpunit.xml.dist export-ignore
 README.md export-ignore
 webpack.config.js export-ignore

.github/workflows/lint.yml

@@ -21,18 +21,18 @@ jobs:
     steps:
     - uses: actions/checkout@v4
 
-    - name: Setup node v16 and npm cache
+    - name: Setup node
       uses: actions/setup-node@v4
       with:
         node-version-file: .nvmrc
         cache: npm
 
-    - name: Install Node dependencies
+    - name: Install node dependencies
       run: npm ci --no-optional
 
     - name: Get updated JS files
       id: changed-files
-      uses: tj-actions/changed-files@v42
+      uses: tj-actions/changed-files@v45
       with:
         files: |
           **/*.js
@@ -54,7 +54,7 @@ jobs:
     - name: Checkout
       uses: actions/checkout@v4
 
-    - name: Set standard 10up cache directories
+    - name: Set standard cache directories
       run: |
         composer config -g cache-dir "${{ env.COMPOSER_CACHE }}"
 
@@ -78,7 +78,7 @@ jobs:
 
     - name: Get updated PHP files
       id: changed-files
-      uses: tj-actions/changed-files@v42
+      uses: tj-actions/changed-files@v45
       with:
         files: |
           **/*.php

.github/workflows/phpstan.yml

@@ -0,0 +1,33 @@
+name: PHPStan
+
+on:
+  push:
+    branches:
+      - develop
+      - trunk
+  pull_request:
+    branches:
+      - develop
+
+jobs:
+
+  phpstan:
+    name: PHPStan
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set PHP version
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: '7.4'
+          coverage: none
+          tools: composer:v2
+
+      - name: Install dependencies
+        run: composer install
+
+      - name: PHPStan
+        run: composer phpstan

composer.json

@@ -28,17 +28,24 @@
   },
   "require-dev": {
     "10up/phpcs-composer": "^3.0",
-    "yoast/phpunit-polyfills": "^1.0.0"
+    "yoast/phpunit-polyfills": "^1.0.0",
+    "szepeviktor/phpstan-wordpress": "dev-master",
+    "phpstan/extension-installer": "1.4.x-dev",
+    "php-stubs/wp-cli-stubs": "dev-master",
+    "johnbillion/wp-compat": "dev-trunk",
+    "phpstan/phpstan-deprecation-rules": "1.2.x-dev"
   },
   "scripts": {
     "lint": "phpcs -s . --runtime-set testVersion 7.4-",
     "lint-fix": "phpcbf .",
+    "phpstan": "phpstan analyse --memory-limit=2048M -v",
     "pre-autoload-dump": "Aws\\Script\\Composer\\Composer::removeUnusedServices"
   },
   "minimum-stability": "dev",
   "config": {
     "allow-plugins": {
-      "dealerdirect/phpcodesniffer-composer-installer": true
+      "dealerdirect/phpcodesniffer-composer-installer": true,
+      "phpstan/extension-installer": true
     }
   },
   "archive": {