add lint workflow

.github/workflows/lint.yml

@@ -0,0 +1,63 @@
+name: Lint
+on:
+  push:
+    branches:
+      - '**'
+    paths:
+      - '**.php'
+  pull_request:
+    types: [opened, edited, reopened, ready_for_review]
+    paths:
+      - '**.php'
+  workflow_dispatch:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event_name == 'pull_request' && github.head_ref || github.sha }}
+  cancel-in-progress: true
+
+jobs:
+  phpcs:
+    name: Run PHP Code Sniffer
+    runs-on: ubuntu-latest
+    steps:
+
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      # User PHP 7.4 here for compatibility with the WordPress codesniffer rules.
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: '7.4'
+          coverage: none
+          tools: composer, cs2pr
+
+      - uses: technote-space/get-diff-action@v6
+        with:
+          SUFFIX_FILTER: .php
+
+      - name: Get Composer cache directory
+        id: composer-cache
+        run: echo "dir=$(composer config cache-files-dir)" >> $GITHUB_OUTPUT
+        if: "!! env.GIT_DIFF"
+
+      - name: Cache Composer vendor directory
+        uses: actions/cache@v3
+        with:
+          path: ${{ steps.composer-cache.outputs.dir }}
+          key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-composer-
+        if: "!! env.GIT_DIFF"
+
+      - name: Validate composer.json and composer.lock
+        run: composer validate
+        if: "!! env.GIT_DIFF"
+
+      - name: Install dependencies
+        run: composer install --no-progress --optimize-autoloader --prefer-dist
+        if: "!! env.GIT_DIFF"
+
+      - name: Detecting PHP Code Standards Violations
+        run: vendor/bin/phpcs --standard=phpcs.xml -s ${{ env.GIT_DIFF }}
+        if: "!! env.GIT_DIFF"

phpcs.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0"?>
+<ruleset name="Performance-Module">
+    <rule ref="Newfold"/>
+    <config name="testVersion" value="7.3-"/>
+    <config name="minimum_supported_wp_version" value="6.3"/>
+    <rule ref="WordPress-Core">
+        <exclude name="WordPress.NamingConventions.ValidFunctionName.MethodNameInvalid"/>
+        <exclude name="WordPress.NamingConventions.ValidVariableName.VariableNotSnakeCase"/>
+        <exclude name="WordPress.Files.FileName.InvalidClassFileName"/>
+        <exclude name="WordPress.Files.FileName.NotHyphenatedLowercase"/>
+    </rule>
+</ruleset>