Implement gherkin linter in GH action

.distignore

@@ -17,6 +17,8 @@ tests
 .distignore
 .editorconfig
 .eslintrc.js
+.gherkin-lintignore
+.gherkin-lintrc
 .gitattributes
 .gitignore
 .nvmrc

.gherkin-lintignore

@@ -0,0 +1,2 @@
+node_modules/**
+vendor/**

.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"
+}

.gitattributes

@@ -12,6 +12,8 @@
 
 /.editorconfig export-ignore
 /.eslintrc.js export-ignore
+/.gherkin-lintignore export-ignore
+/.gherkin-lintrc export-ignore
 /.nvmrc export-ignore
 /.wp-env.json export-ignore
 /composer.lock export-ignore

.github/workflows/gherkin-lint.yml

@@ -0,0 +1,44 @@
+name: Gherkin Linting
+
+on:
+  push:
+    branches:
+      - trunk
+      - 'release/**'
+    # Only run if feature files are changed.
+    paths:
+      - '.github/workflows/gherkin-lint.yml'
+      - '**.feature'
+  pull_request:
+    branches:
+      - trunk
+      - 'release/**'
+      - 'feature/**'
+    # Only run if feature files are changed.
+    paths:
+      - '.github/workflows/gherkin-lint.yml'
+      - '**.feature'
+    types:
+      - opened
+      - reopened
+      - synchronize
+
+jobs:
+  gherkin-lint:
+    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
+        with:
+          node-version-file: '.nvmrc'
+          cache: npm
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Gherkin lint
+        run: npm run lint-gherkin