Add JS linter and fix reported issues

.editorconfig

@@ -0,0 +1,25 @@
+# This file is for unifying the coding style for different editors and IDEs
+# editorconfig.org
+
+# WordPress Coding Standards
+# https://make.wordpress.org/core/handbook/coding-standards/
+
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+indent_style = tab
+
+[*.{yml,yaml}]
+indent_style = space
+indent_size = 2
+
+[*.{gradle,java,kt}]
+indent_style = space
+
+[packages/react-native-*/**.xml]
+indent_style = space
+

.eslintrc

@@ -0,0 +1,3 @@
+{
+    "extends": [ "plugin:@wordpress/eslint-plugin/recommended" ]
+}

.github/workflows/lint-js.yml

@@ -0,0 +1,37 @@
+name: Lint JS
+
+on:
+  # Run on pushes to select branches and on all pull requests.
+  push:
+    branches:
+      - master
+      - develop
+      - trunk
+      - 'feature/**'
+      - 'release/**'
+      - 'hotfix/[0-9]+.[0-9]+*'
+  pull_request:
+  # Allow manually triggering the workflow.
+  workflow_dispatch:
+
+# Cancels all previous workflow runs for the same branch that have not yet completed.
+concurrency:
+  # The concurrency group contains the workflow name and the branch name.
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+
+    name: "Lint: JS"
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v3
+
+      # The lint stage doesn't run the unit tests or use code style, so no need for PHPUnit, WPCS or phpcompatibility.
+      - name: 'Install NPM packages'
+        run: npm install
+      - name: 'Run ESLint'
+        run: npm run lint:js

.github/workflows/lint.yml → .github/workflows/lint-php.yml

@@ -1,4 +1,4 @@
-name: Lint
+name: Lint PHP
 
 on:
   # Run on pushes to select branches and on all pull requests.
@@ -69,4 +69,4 @@ jobs:
           tools: cs2pr
 
       - name: Lint against parse errors
-        run: composer lint -- --checkstyle | cs2pr
+        run: composer lint -- --checkstyle | cs2pr

package.json

@@ -16,8 +16,11 @@
     "build": "npx webpack",
     "dev": "npx webpack --watch --mode development",
     "dist": "npx webpack --mode production && composer install --no-dev && composer dump-autoload --no-dev -o && wp-scripts plugin-zip && mv accessibility-checker.zip ./dist && composer install",
-    "lint": "./vendor/bin/phpcs",
-    "test:e2e": "npx wp-env clean tests && npx playwright test ./e2e/specs"    
+    "lint": "./vendor/bin/phpcs && npm run lint:js",
+    "lint:php": "./vendor/bin/phpcs",
+		"lint:js": "wp-scripts lint-js",
+		"lint:js:fix": "wp-scripts lint-js --fix",
+    "test:e2e": "npx wp-env clean tests && npx playwright test ./e2e/specs"
   },
   "files": [
     "LICENSE.txt",
@@ -33,9 +36,10 @@
   "devDependencies": {
     "@babel/core": "^7.22.1",
     "@babel/preset-env": "^7.22.4",
-    "@babel/preset-react": "^7.22.3", 
+    "@babel/preset-react": "^7.22.3",
     "@floating-ui/dom": "^1.2.9",
     "@wordpress/env": "*",
+    "@wordpress/eslint-plugin": "^17.5.0",
     "@wordpress/scripts": "^26.5.0",
     "axe-core": "^4.7.2",
     "babel-loader": "^9.1.2",