Conventional Commit

<emoji> <type>[optional scope]: <description>

[optional body]

[optional footer(s)]

What changed?          → Description (max 72 chars, imperative tense)
Which module?          → Scope
Is "why" non-obvious?  → Add body
Closes an issue?       → Footer: Fixes #N
Breaking API change?   → Footer: BREAKING CHANGE: ...
Pair programmed?       → Footer: Co-authored-by: ...

🩹 fix: null pointer on login          ← unclear
🩹 fix(auth): null pointer on login    ← immediately clear

✅ 🩹 fix(auth): prevent token refresh race condition
✅ ✨ feat(user): add email verification on registration
❌ 🩹 fix(auth): fixed token refresh
❌ ✨ feat(user): adding email verification

# Body NOT needed — reason is obvious
🔨 chore(deps): bump lodash from 4.17.20 to 4.17.21

# Body NEEDED — reason is not obvious from the diff
🩹 fix(db): add connection timeout to pool config

Without a timeout, idle connections were held open indefinitely.
Under high load this exhausted the pool and caused new requests
to hang. Setting timeout to 30s matches the upstream DB setting.

Fixes #482     ← automatically closes the GitHub issue on merge
Closes #301    ← same as Fixes
Refs #210      ← links without closing

BREAKING CHANGE: /api/v1/users now returns `userId` instead of `id`

Consumers must update their response parsing. See migration guide
in docs/migrations/v2.md

Co-authored-by: Jane Doe <jane@example.com>

🩹 fix(auth): prevent token refresh race condition

When two concurrent requests arrived with an expired token,
both triggered a refresh simultaneously. The second refresh
invalidated the first token, causing one request to fail with
401 even though it had just refreshed.

Added a Redis-based mutex lock to serialize refresh calls
per user. Lock TTL is set to 5s to prevent deadlocks on crash.

Fixes #482
Co-authored-by: Jane Doe <jane@example.com>

🩹 fix(db): add connection timeout to pool config

Without a timeout, idle connections were held open indefinitely.
Under high load this exhausted the pool and caused new requests
to hang. Setting timeout to 30s matches the upstream DB setting.

Fixes #310

🩹 fix(ui): prevent modal from closing on outside scroll

⚡️ perf(router): lazy load dashboard route to reduce initial bundle

✨ feat(api): replace axios with native fetch

Removes axios dependency entirely. All interceptors have been
rewritten as middleware functions in src/api/middleware.ts.

BREAKING CHANGE: custom axios instances in plugins must be
migrated to the new middleware API. See docs/migration-v3.md.
Refs #201

🩹 fix(config): fall back to default when config file is malformed

Previously the tool crashed with an unhandled JSON parse error.
Now it logs a warning and continues with default configuration.

Fixes #88

✨ feat(plugin): expose beforeTransform hook for plugin authors

Allows plugins to intercept and modify data before the core
transformation runs. Hook receives the raw input and must
return the transformed value or the original unchanged.

Refs #120

✨ feat(types): export PluginConfig interface as public API

BREAKING CHANGE: PluginConfig was previously internal. Consumers
who duck-typed this interface must now import it explicitly.

npm install --save-dev @commitlint/cli @commitlint/config-conventional \
  conventional-changelog-conventionalcommits husky

import type { ParserPreset, UserConfig } from '@commitlint/types';
import config from '@commitlint/config-conventional';
import createPreset from 'conventional-changelog-conventionalcommits';
import { merge } from 'lodash-es';

// Build emoji regex dynamically from your type enum
async function createEmojiParser(): Promise<ParserPreset> {
  const emojiRegexPart = Object.values(config.prompt.questions.type.enum)
    .map((value) => (value as any).emoji.trim())
    .join('|');

  const parserOpts = {
    headerPattern: new RegExp(
      `^(?:${emojiRegexPart})\\s+(\\w*)(?:\\((.*)\\))?!?:\\s+(.*)$`
    ),
    breakingHeaderPattern: new RegExp(
      `^(?:${emojiRegexPart})\\s+(\\w*)(?:\\((.*)\\))?!:\\s+(.*)$`
    ),
    headerCorrespondence: ['type', 'scope', 'subject'],
  };

  const emojiParser = merge({}, await createPreset(), {
    conventionalChangelog: { parserOpts },
    parserOpts,
    recommendedBumpOpts: { parserOpts },
  });

  return emojiParser;
}

const emojiParser = await createEmojiParser();

const config: UserConfig = {
  extends: ['@commitlint/config-conventional'],
  parserPreset: emojiParser,
  rules: {
    'type-enum': [
      2,
      'always',
      ['feat', 'fix', 'refactor', 'build', 'perf', 'test', 'docs', 'chore', 'revert'],
    ],
  },
  prompt: {
    questions: {
      type: {
        enum: {
          feat:     { emoji: '✨', description: 'User-facing new feature' },
          fix:      { emoji: '🩹', description: 'Bug fix' },
          refactor: { emoji: '♻️', description: 'Internal improvement, no behavior change' },
          build:    { emoji: '👷', description: 'Build system & pipelines' },
          perf:     { emoji: '⚡️', description: 'Performance optimization' },
          test:     { emoji: '✅', description: 'Add or fix test cases' },
          docs:     { emoji: '📝', description: 'Documentation update' },
          chore:    { emoji: '🔨', description: 'Maintenance, deps, config, formatting' },
          revert:   { emoji: '⏪', description: 'Revert a previous commit' },
        },
        headerWithEmoji: true, // includes emoji in the final commit header
      },
    },
  },
};

export default config;

npx husky init
echo "npx --no -- commitlint --edit \$1" > .husky/commit-msg

# .github/workflows/commitlint.yml
name: Lint Commits
on: [pull_request]
jobs:
  commitlint:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
        with:
          fetch-depth: 0
      - uses: wagoid/commitlint-github-action@v5