Add ESLint rule to check for relative imports

Relative imports do not work in most Rails apps.

.github/workflows/lint.yml

@@ -15,6 +15,26 @@ jobs:
           bundler-cache: true
       - name: Lint Ruby files
         run: bundle exec standardrb
+  ESLint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Setup Node
+        uses: actions/setup-node@v3
+        with:
+          node-version: "18"
+      - name: Restore node_modules cache
+        uses: actions/cache@v3
+        with:
+          path: node_modules
+          key: ${{ runner.os }}-node-modules-${{ hashFiles('package.json') }}
+          restore-keys: |
+            ${{ runner.os }}-node-modules
+      - name: Install dependencies
+        run: yarn install
+      - name: Lint code
+        run: yarn eslint
   Prettier:
     runs-on: ubuntu-latest
     steps:

eslint.config.js

@@ -0,0 +1,17 @@
+export default [
+  {
+    rules: {
+      "no-restricted-imports": [
+        "error",
+        {
+          patterns: [
+            {
+              group: ["./", "../"],
+              message: "Relative imports are not allowed."
+            }
+          ]
+        }
+      ]
+    }
+  }
+]

package.json

@@ -3,6 +3,7 @@
   "scripts": {
     "test": "jest",
     "lint": "prettier --check 'app/javascript/**/*.js'",
+    "eslint": "eslint app/javascript/**/*.js",
     "build": "rollup -c"
   },
   "keywords": [],
@@ -25,6 +26,7 @@
     "@rollup/plugin-node-resolve": "^15.2.3",
     "@rollup/plugin-terser": "^0.4.4",
     "babel-jest": "^29.6.4",
+    "eslint": "^8.56.0",
     "jest": "^29.6.4",
     "jest-environment-jsdom": "^29.6.4",
     "jquery": "^3.7.1",