Commit msg

Commit Message Generator

Generate a well-structured commit message based on the current staged changes.

Step 1: Read the staged diff

git diff --staged

If there are no staged changes, tell the user and stop. Suggest they run git add <files> first.

Also check the language used in recent commits to decide whether the message should be in Traditional Chinese or English:

git log --oneline -5

Use Traditional Chinese if recent commits are in Chinese, otherwise use English.

Step 2: Analyze the changes

Look at what files changed and what the diff shows. Ask yourself:

• What was the purpose of this change from a user's perspective?
• Does it add new capability, fix broken behavior, update structure, or something else?

Step 3: Pick the commit type

Choose exactly one type based on the primary intent of the change:

Type	When to use
feat	New feature for the user (not a build-script feature)
fix	Bug fix for the user (not a build-script fix)
docs	Documentation only — no code logic changed
style	Formatting, whitespace, semicolons — zero semantic change
refactor	Code restructured without fixing a bug or adding a feature
chore	Maintenance, dependency updates, config — no production code touched
perf	Performance improvement
revert	Reverts a previous commit
test	Adding or fixing tests — no production code change
build	Build system or external dependency changes (e.g., webpack, npm scripts)
ci	CI/CD configuration (e.g., GitHub Actions, workflows)

When the diff spans multiple types, pick the one that best describes the primary intent.

Step 4: Write the commit message

Title format:

type: short description (imperative mood, under 72 chars)

Examples:

• feat: 新增使用者登入功能
• fix: 修正 MongoDB 連線逾時問題
• refactor: extract database connection logic into helper

Body (bullet points):

List specific changes and their reasons below the title, each starting with -. Focus on the why and what, not just restating the file names.

feat: 新增跨容器通訊範例

- 新增 Node.js app 容器，透過 Docker 自訂網路連接 MongoDB
- 使用 mongoose 連線，並修正 useUnifiedTopology 設定以符合新版 API
- 在 docker-compose.yml 定義 app-network 讓容器間可互相解析主機名稱

Step 5: Present and confirm

Display the commit message in a code block so the user can copy it easily:

```
type: title here

- detail one
- detail two
- detail three
```

Then ask: "要直接用這個 commit message 提交嗎？" (or in English if the message is in English: "Would you like me to apply this commit message now?")

If the user confirms, run:

git commit -m "$(cat <<'EOF'
type: title here

- detail one
- detail two
- detail three
EOF
)"

If the user wants edits, apply them first before committing.