Introduce Gherkin linter

Author: ernilambar

.gherkin-lintrc

@@ -0,0 +1,32 @@
+{
+  "file-name": [
+    "on",
+    {
+      "style": "kebab-case"
+    }
+  ],
+  "indentation": [
+    "on",
+    {
+      "Feature": 0,
+      "Background": 2,
+      "Scenario": 2,
+      "Examples": 4,
+      "Step": 4,
+      "given": 4,
+      "example": 6,
+      "and": 4
+    }
+  ],
+  "no-dupe-feature-names": "on",
+  "no-dupe-scenario-names": "off",
+  "no-empty-file": "on",
+  "no-files-without-scenarios": "on",
+  "no-multiple-empty-lines": "on",
+  "no-partially-commented-tag-lines": "on",
+  "no-trailing-spaces": "on",
+  "no-unnamed-features": "on",
+  "no-unnamed-scenarios": "on",
+  "no-scenario-outlines-without-examples": "on",
+  "use-and": "on"
+}

.github/workflows/reusable-code-quality.yml

@@ -70,6 +70,22 @@ jobs:
         if: steps.check_linter_file.outputs.files_exists == 'true'
         run: vendor/bin/parallel-lint -j 10 . --show-deprecated --exclude vendor --exclude .git --checkstyle | cs2pr
 
+  lint-gherkin: #----------------------------------------------------------------
+    name: Lint Gherkin Feature files
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out source code
+        uses: actions/checkout@v4
+
+      - name: Setup node
+        uses: actions/setup-node@v4
+
+      - name: Download lint rules
+        run: curl https://raw.githubusercontent.com/wp-cli/.github/refs/heads/main/.gherkin-lintrc -o $RUNNER_TEMP/.gherkin-lintrc
+
+      - name: Run linter
+        run: npx --yes gherkin-lint -c $RUNNER_TEMP/.gherkin-lintrc
+
   phpcs: #----------------------------------------------------------------------
     name: PHPCS
     runs-on: ubuntu-latest