ci: add conventional commits changelog generation and commit linting (#641)

- Add git-cliff config (cliff.toml) for changelog generation from conventional commits
- Add GitHub Actions workflow to generate CHANGELOG.md on tag push or manual trigger
- Add commitlint config enforcing conventional commit format on PRs
- Add commitlint GitHub Actions workflow for PR validation

Supported commit types: feat, fix, docs, example, examples, chore, refactor, perf, test, ci, revert

Author: bnusunny

.github/workflows/changelog.yaml

@@ -0,0 +1,54 @@
+name: Changelog
+
+on:
+  push:
+    tags:
+      - "v*"
+  workflow_dispatch:
+    inputs:
+      version:
+        description: "Version tag to generate changelog for (e.g. v1.0.0)"
+        required: true
+        type: string
+
+permissions:
+  contents: write
+
+jobs:
+  changelog:
+    name: Generate Changelog
+    runs-on: ubuntu-latest
+    env:
+      VERSION_TAG: ${{ inputs.version || github.ref_name }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Generate changelog
+        uses: orhun/git-cliff-action@v4
+        id: git-cliff
+        with:
+          config: cliff.toml
+          args: --verbose --tag ${{ env.VERSION_TAG }}
+        env:
+          OUTPUT: CHANGELOG.md
+          GITHUB_REPO: ${{ github.repository }}
+
+      - name: Commit changelog
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+          git add CHANGELOG.md
+          git commit -m "chore: update changelog for ${{ env.VERSION_TAG }}" || true
+          git push origin HEAD:main
+
+      - name: Create/update GitHub release body
+        uses: orhun/git-cliff-action@v4
+        with:
+          config: cliff.toml
+          args: --verbose --latest --strip header
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GITHUB_REPO: ${{ github.repository }}

.github/workflows/commitlint.yaml

@@ -0,0 +1,30 @@
+name: Commit Lint
+
+on:
+  pull_request:
+    branches:
+      - main
+
+permissions:
+  contents: read
+
+jobs:
+  commitlint:
+    name: Lint Commit Messages
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+
+      - name: Install commitlint
+        run: npm install --save-dev @commitlint/{cli,config-conventional}
+
+      - name: Lint commits
+        run: npx commitlint --from ${{ github.event.pull_request.base.sha }} --to ${{ github.event.pull_request.head.sha }} --verbose

cliff.toml

@@ -0,0 +1,71 @@
+[changelog]
+header = """
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+This changelog is automatically generated based on [Conventional Commits](https://www.conventionalcommits.org/).\n
+"""
+body = """
+{%- macro remote_url() -%}
+  https://github.com/{{ remote.github.owner }}/{{ remote.github.repo }}
+{%- endmacro -%}
+
+{% if version -%}
+## [{{ version | trim_start_matches(pat="v") }}]\
+  {% if commit_id %}({{ self::remote_url() }}/tree/{{ version }}){% endif %}\
+  {% if timestamp %} - {{ timestamp | date(format="%Y-%m-%d") }}{% endif %}
+{% else -%}
+## [Unreleased]
+{% endif -%}
+
+{% for group, commits in commits | group_by(attribute="group") %}
+### {{ group | striptags | trim | upper_first }}
+{% for commit in commits
+| filter(attribute="scope")
+| sort(attribute="scope") %}
+  - *({{ commit.scope }})* {{ commit.message | upper_first }}\
+    {% if commit.github.username %} by @{{ commit.github.username }}{%- endif -%}
+    {% if commit.github.pr_number %} in \
+      [#{{ commit.github.pr_number }}]({{ self::remote_url() }}/pull/{{ commit.github.pr_number }})\
+    {%- endif %}
+{%- endfor -%}
+{% for commit in commits %}
+{%- if not commit.scope %}
+  - {{ commit.message | upper_first }}\
+    {% if commit.github.username %} by @{{ commit.github.username }}{%- endif -%}
+    {% if commit.github.pr_number %} in \
+      [#{{ commit.github.pr_number }}]({{ self::remote_url() }}/pull/{{ commit.github.pr_number }})\
+    {%- endif %}
+{%- endif -%}
+{%- endfor -%}
+{% endfor %}
+"""
+footer = ""
+trim = true
+
+[git]
+conventional_commits = true
+filter_unconventional = false
+split_commits = false
+commit_parsers = [
+  { message = "^feat", group = "<!-- 0 -->🚀 Features" },
+  { message = "^fix", group = "<!-- 1 -->🐛 Bug Fixes" },
+  { message = "^perf", group = "<!-- 2 -->⚡ Performance" },
+  { message = "^doc", group = "<!-- 3 -->📚 Documentation" },
+  { message = "^example", group = "<!-- 4 -->📦 Examples" },
+  { message = "^refactor", group = "<!-- 5 -->🔧 Refactoring" },
+  { message = "^chore\\(deps\\)", group = "<!-- 6 -->📦 Dependencies" },
+  { message = "^chore|^ci", group = "<!-- 7 -->🏗️ Maintenance" },
+  { message = "^test", group = "<!-- 8 -->🧪 Testing" },
+  { message = "^Bump ", group = "<!-- 6 -->📦 Dependencies" },
+  { message = "^.*", group = "<!-- 9 -->🔀 Other" },
+]
+protect_breaking_commits = true
+filter_commits = false
+tag_pattern = "v[0-9].*"
+sort_commits = "newest"
+
+[remote.github]
+owner = "awslabs"
+repo = "aws-lambda-web-adapter"

commitlint.config.js

@@ -0,0 +1,26 @@
+module.exports = {
+  extends: ['@commitlint/config-conventional'],
+  rules: {
+    'type-enum': [
+      2,
+      'always',
+      [
+        'feat',
+        'fix',
+        'docs',
+        'example',
+        'examples',
+        'chore',
+        'refactor',
+        'perf',
+        'test',
+        'ci',
+        'revert',
+      ],
+    ],
+    'subject-case': [0],
+    'body-max-line-length': [0],
+    'footer-max-line-length': [0],
+    'header-max-length': [2, 'always', 120],
+  },
+};