[#143] Added linting of the GitHub actions.

.github/.yamllint-for-gha.yml

@@ -0,0 +1,17 @@
+# Yamllint configuration file used to check GitHub Actions configuration files. 
+extends: default
+
+rules:
+  comments:
+    min-spaces-from-content: 1
+  document-start:
+    present: false
+  empty-lines:
+    max: 1
+    max-start: 0
+    max-end: 0
+  line-length:
+    max: 255
+  truthy:
+    allowed-values: ['true', 'false']
+    check-keys: false

.github/workflows/release-php.yml

@@ -30,17 +30,17 @@ jobs:
       - name: Install dependencies
         run: composer install
 
-        #;< PHP_PHAR
+      # yamllint disable-line #;< PHP_PHAR
       - name: Build PHAR
         run: composer build
 
       - name: Test PHAR
         run: ./.build/php-command.phar || exit 1
-        #;> PHP_PHAR
+      # yamllint disable-line #;> PHP_PHAR
 
       - name: Get tag name
         id: get-version
-        run: echo "version=${GITHUB_REF#refs/tags/}" >> $GITHUB_OUTPUT
+        run: echo "version=${GITHUB_REF#refs/tags/}" >> "$GITHUB_OUTPUT"
 
       - name: Create Release
         uses: softprops/action-gh-release@v2

.github/workflows/test-actions.yml

@@ -0,0 +1,26 @@
+name: Test Actions
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+      - 'feature/**'
+
+jobs:
+  test-actions:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Check coding standards with yamllint
+        run: yamllint --config-file .github/.yamllint-for-gha.yml .github/workflows
+        continue-on-error: ${{ vars.CI_LINT_IGNORE_FAILURE == '1' }}
+
+      - name: Check coding standards with actionlint
+        run: docker run --rm -v "${GITHUB_WORKSPACE:-.}":/app --workdir /app rhysd/actionlint:1.6.27
+        continue-on-error: ${{ vars.CI_LINT_IGNORE_FAILURE == '1' }}

.github/workflows/test-php.yml

@@ -57,7 +57,7 @@ jobs:
           fail_ci_if_error: true
           token: ${{ secrets.CODECOV_TOKEN }}
 
-  #;< PHP_PHAR
+  # yamllint disable-line #;< PHP_PHAR
   build-php:
     runs-on: ubuntu-latest
     steps:
@@ -83,4 +83,4 @@ jobs:
 
       - name: Test PHAR
         run: ./.build/php-command.phar || exit 1
-  #;> PHP_PHAR
+        # yamllint disable-line #;> PHP_PHAR

.github/workflows/test-scaffold.yml

@@ -42,7 +42,7 @@ jobs:
         run: npm --prefix=tests/scaffold ci
 
       - name: Run tests
-        run: kcov --include-pattern=.sh,.bash --bash-parse-files-in-dir=. --exclude-pattern=vendor,node_modules,.scaffold-coverage-html $(pwd)/.scaffold-coverage-html ./tests/scaffold/node_modules/.bin/bats tests/scaffold
+        run: kcov --include-pattern=.sh,.bash --bash-parse-files-in-dir=. --exclude-pattern=vendor,node_modules,.scaffold-coverage-html "$(pwd)"/.scaffold-coverage-html ./tests/scaffold/node_modules/.bin/bats tests/scaffold
 
       - name: Upload coverage report as an artifact
         uses: actions/upload-artifact@v4

docs/content/ci/test.mdx

@@ -58,7 +58,7 @@ The workflow includes steps for linting, testing, and code coverage.
 
 [//]: # (#;< SHELL)
 
-## Node.js job
+## Shell job
 
 - Runs on a matrix of several OSes.
 - Checks out code.
@@ -71,6 +71,17 @@ The workflow includes steps for linting, testing, and code coverage.
 
 [//]: # (#;> SHELL)
 
+## Actions job
+
+Used to validate the GitHub Actions workflow files in the repository.
+
+- Checks out code.
+- Runs code linting with [`yamllint`](https://github.com/adrienverge/yamllint) using [configuration](https://github.com/AlexSkrypnyk/scaffold/blob/main/.github/.yamllint-for-gha.yml) file.
+- Runs code linting with [`actionlint`](https://github.com/rhysd/actionlint).
+
+Add `CI_LINT_IGNORE_FAILURE` with a value of `1` to your repository's variables
+to ignore linting failures.
+
 ## Code coverage
 
 The workflow publishes code coverage reports for PHP and Node.js projects to