manage-git-branches（管理 git 分支）

Manage Git Branches

Create, switch, sync, and clean up branches following consistent naming conventions.

When to Use

• Starting work on a new feature or bug fix
• Switching between tasks on different branches
• Keeping a feature branch up to date with main
• Cleaning up branches after merging pull requests
• Listing and inspecting branches

Inputs

• Required: Repository with at least one commit
• Optional: Branch naming convention (default: type/description)
• Optional: Base branch for new branches (default: main)
• Optional: Remote name (default: origin)

Procedure

Step 1: Create a Feature Branch

Use a consistent naming convention:

# Create and switch to a new branch from main
git checkout -b feature/add-weighted-mean main

# Or using the newer switch command
git switch -c feature/add-weighted-mean main

Expected: New branch created and checked out. git branch shows the new branch with an asterisk.

On failure: If the base branch doesn't exist locally, fetch first: git fetch origin main && git checkout -b feature/name origin/main.

Step 2: Track Remote Branches

Set up tracking when pushing a new branch for the first time:

# Push and set upstream tracking
git push -u origin feature/add-weighted-mean

# Check tracking relationship
git branch -vv

To check out a remote branch that someone else created:

git fetch origin
git checkout feature/their-branch
# Git auto-creates a local tracking branch

Expected: Local branch tracks the corresponding remote branch. git branch -vv shows the upstream.

On failure: If auto-tracking fails, set it manually: git branch --set-upstream-to=origin/feature/name feature/name.

Step 3: Switch Branches Safely

Before switching, ensure the working tree is clean:

# Check for uncommitted changes
git status

If changes exist, either commit or stash them:

# Option 1: Commit work in progress
git add <files>
git commit -m "wip: save progress on validation logic"

# Option 2: Stash changes temporarily
git stash push -m "validation work in progress"

# Switch branches
git checkout main

# Later, restore stashed changes
git checkout feature/add-weighted-mean
git stash pop

List and manage stashes:

# List all stashes
git stash list

# Apply a specific stash (without removing it)
git stash apply stash@{1}

# Drop a stash
git stash drop stash@{0}

Expected: Branch switch succeeds. Working tree reflects the target branch's state. Stashed changes are recoverable.

On failure: If switch is blocked by uncommitted changes that would be overwritten, stash or commit first. git stash cannot stash untracked files unless you use git stash push -u.

Step 4: Sync with Upstream

Keep your feature branch up to date with the base branch:

# Fetch latest changes
git fetch origin

# Rebase onto latest main (preferred — keeps linear history)
git rebase origin/main

# Or merge main into your branch (creates merge commit)
git merge origin/main

Expected: Branch now includes the latest changes from main. No conflicts, or conflicts resolved (see resolve-git-conflicts).

On failure: If rebase causes conflicts, resolve each one and git rebase --continue. If the conflicts are too complex, abort with git rebase --abort and try git merge origin/main instead.

Step 5: Clean Up Merged Branches

After pull requests are merged, remove stale branches:

# Delete a local branch that has been merged
git branch -d feature/add-weighted-mean

# Delete a local branch (force, even if not merged)
git branch -D feature/abandoned-experiment

# Delete a remote branch
git push origin --delete feature/add-weighted-mean

# Prune remote-tracking references for deleted remote branches
git fetch --prune

Expected: Merged branches are removed locally and remotely. git branch shows only active branches.

On failure: git branch -d refuses to delete unmerged branches. If the branch was merged via squash merge on GitHub, Git may not recognize it as merged. Use git branch -D if you are certain the work is preserved.

Step 6: List and Inspect Branches

# List local branches
git branch

# List all branches (local and remote)
git branch -a

# List branches with last commit info
git branch -v

# List branches merged into main
git branch --merged main

# List branches NOT yet merged
git branch --no-merged main

# See which remote branch each local branch tracks
git branch -vv

Expected: Clear view of all branches, their status, and tracking relationships.

On failure: If remote branches appear stale, run git fetch --prune to clean up references to deleted remote branches.

Validation

• Branch names follow the agreed naming convention
• Feature branches are created from the correct base branch
• Local branches track their remote counterparts
• Merged branches are cleaned up (local and remote)
• Working tree is clean before branch switches
• Stashed changes are not left orphaned

Common Pitfalls

• Working on main directly: Always create a feature branch. Committing directly to main makes it difficult to create PRs and collaborate.
• Forgetting to fetch before branching: Creating a branch from a stale local main means you start behind. Always git fetch origin first.
• Long-lived branches: Feature branches that live for weeks accumulate merge conflicts. Sync frequently and keep branches short-lived.
• Orphaned stashes: git stash is temporary storage. Don't rely on it for long-term work. Commit or branch instead.
• Deleting unmerged work: git branch -D is destructive. Double-check with git log branch-name before force-deleting.
• Not pruning: Remote branches deleted on GitHub still appear locally until you git fetch --prune.

Related Skills

• commit-changes - committing work on branches
• create-pull-request - opening PRs from feature branches
• resolve-git-conflicts - handling conflicts during sync
• configure-git-repository - repository setup and branch strategy