chore(ci): enable linter on PR (#3257)

* ci: add changed-file lint gate

* ci: run lint job on node 22

Author: nkaradzhov

.github/workflows/tests.yml

@@ -16,6 +16,22 @@ on:
     paths-ignore:
       - "**/*.md"
 jobs:
+  lint:
+    if: github.event_name == 'pull_request'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 1
+      - name: Use Node.js 22
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22
+      - name: Install Packages
+        run: npm ci
+      - name: Lint changed files
+        run: npm run lint:changed
+
   tests:
     runs-on: ubuntu-latest
     strategy:
@@ -41,4 +57,4 @@ jobs:
             node-version: ${{ matrix.node-version }}
             redis-tag: ${{ matrix.redis.tag }}
             redis-version: ${{ matrix.redis.version }}
-            otel-authorization-token: ${{ secrets.SELF_CHECK_OTEL_AUTHORIZATION_TOKEN }}
+            otel-authorization-token: ${{ secrets.SELF_CHECK_OTEL_AUTHORIZATION_TOKEN }}

eslint.config.mjs

@@ -0,0 +1,49 @@
+import js from '@eslint/js';
+import globals from 'globals';
+import tseslint from 'typescript-eslint';
+
+export default [
+  {
+    ignores: [
+      '**/coverage/**',
+      '**/dist/**',
+      '**/junit-results/**',
+      '**/node_modules/**',
+      'documentation/**'
+    ]
+  },
+  js.configs.recommended,
+  ...tseslint.configs.recommended,
+  {
+    files: ['**/*.{cjs,js,mjs,ts}'],
+    languageOptions: {
+      ecmaVersion: 'latest',
+      sourceType: 'module',
+      globals: {
+        ...globals.es2023,
+        ...globals.node
+      }
+    },
+    rules: {
+      'no-empty': ['error', { allowEmptyCatch: true }]
+    }
+  },
+  {
+    files: ['**/*.ts'],
+    rules: {
+      'no-undef': 'off',
+      'no-unused-vars': 'off',
+      '@typescript-eslint/no-unused-vars': ['error', {
+        argsIgnorePattern: '^_',
+        caughtErrorsIgnorePattern: '^_',
+        varsIgnorePattern: '^_'
+      }]
+    }
+  },
+  {
+    files: ['**/*.spec.ts', '**/integration-tests/**/*.ts'],
+    languageOptions: {
+      globals: globals.mocha
+    }
+  }
+];