Git Specialist

Git Specialist

Complete Git CLI mastery -- from daily workflows to deep internals.

Workflow

1. Identify the scenario -- what is the user trying to achieve (recovery, history rewrite, workflow optimization, debugging, performance)?
2. Choose the safest approach -- prefer non-destructive commands; warn before any destructive operation (--force, filter-repo, reset --hard)
3. Explain with concrete examples -- show exact commands with realistic output
4. Offer alternatives -- show both the quick way and the "proper" way when they differ

Safety Rules

• Always warn before history-rewriting commands on shared branches
• Prefer --force-with-lease over --force
• Suggest creating a backup branch before destructive operations: git branch backup/before-rewrite
• Recommend git stash or git worktree before risky operations

Core Topics Quick Reference

Power-User Tricks

History Navigation & Search

# Find which commit introduced/removed a string (pickaxe)
git log -S "functionName" --oneline
git log -G "regex_pattern" --oneline

# Show commits that touched a specific function (requires language support)
git log -L :functionName:path/to/file.cs

# Compact graph view with author and relative date
git log --graph --oneline --decorate --all --date=relative --format="%C(yellow)%h%Creset %C(cyan)%ad%Creset %s %C(green)(%an)%Creset"

# Find all commits by a coauthor
git log --all --grep="Co-authored-by:.*Name"

# Commits on branch-a but not on main
git log main..branch-a --oneline

# Find the merge commit that brought a commit into main
git log --ancestry-path --merges <commit>..main | tail -1

Interactive Rebase Mastery

# Rebase last N commits interactively
git rebase -i HEAD~5

# Autosquash: combine fixup commits automatically
git commit --fixup=<target-sha>
git rebase -i --autosquash main

# Reword the root commit
git rebase -i --root

# Rebase onto a different base (transplant a branch)
git rebase --onto new-base old-base feature-branch

# Abort a rebase safely
git rebase --abort

Recovery & Undo

# Undo last commit, keep changes staged
git reset --soft HEAD~1

# Undo last commit, keep changes unstaged
git reset --mixed HEAD~1

# Recover a dropped stash
git fsck --unreachable | grep commit | cut -d' ' -f3 | xargs git show --stat

# Recover deleted branch
git reflog | grep "branch-name"
git checkout -b branch-name <sha-from-reflog>

# Undo a rebase (find pre-rebase HEAD in reflog)
git reflog
git reset --hard HEAD@{n}

# Revert a merge commit (undo merge without rewriting history)
git revert -m 1 <merge-commit-sha>

# Restore a single file from another commit
git restore --source=<commit> -- path/to/file

Stash Power Moves

# Stash only specific files (interactive)
git stash push -p -m "partial stash"

# Stash including untracked files
git stash push --include-untracked -m "with untracked"

# Apply stash to a new branch
git stash branch new-branch-name stash@{0}

# Show stash diff without applying
git stash show -p stash@{0}

# Drop all stashes
git stash clear

Worktree Workflow

# Add a worktree for parallel work (no stash needed)
git worktree add ../hotfix-branch hotfix/issue-123

# List all worktrees
git worktree list

# Remove a worktree after merging
git worktree remove ../hotfix-branch

# Bare repo + worktrees pattern (useful for multiple long-lived branches)
git clone --bare repo.git .bare
echo "gitdir: ./.bare" > .git
git worktree add main
git worktree add develop

Bisect (Automated Bug Hunting)

# Manual bisect
git bisect start
git bisect bad               # current commit is broken
git bisect good v1.0.0       # this tag was working
# Git checks out a middle commit -- test it, then:
git bisect good  # or  git bisect bad
# Repeat until the culprit is found

# Fully automated bisect with a test script
git bisect start HEAD v1.0.0
git bisect run dotnet test --filter "TestName"

# Bisect with a custom script
git bisect run bash -c 'grep -q "expected" output.txt'

# Reset after bisect
git bisect reset

Advanced Diff & Blame

# Word-level diff (great for prose/docs)
git diff --word-diff

# Diff between branches, only file names
git diff main..feature --name-only

# Diff of staged changes only
git diff --cached

# Ignore whitespace in diff
git diff -w

# Blame with line range
git blame -L 10,20 path/to/file

# Blame ignoring whitespace and move detection
git blame -w -M -C path/to/file

# Blame ignoring specific revisions (e.g., formatting commits)
echo "<formatting-sha>" > .git-blame-ignore-revs
git config blame.ignoreRevsFile .git-blame-ignore-revs
git blame path/to/file

Aliases (Productivity Boosters)

# Set up useful aliases
git config --global alias.st "status -sb"
git config --global alias.co "checkout"
git config --global alias.sw "switch"
git config --global alias.last "log -1 --stat"
git config --global alias.unstage "restore --staged"
git config --global alias.graph "log --graph --oneline --decorate --all"
git config --global alias.amend "commit --amend --no-edit"
git config --global alias.undo "reset --soft HEAD~1"
git config --global alias.wip "!git add -A && git commit -m 'WIP [skip ci]'"
git config --global alias.unwip "reset --soft HEAD~1"
git config --global alias.cleanup "!git branch --merged main | grep -v main | xargs -r git branch -d"
git config --global alias.fresh "!git fetch --prune && git rebase origin/main"
git config --global alias.who "shortlog -sne"
git config --global alias.find "log --all -S"

Large Repo Performance

# Sparse checkout (only check out what you need)
git sparse-checkout init --cone
git sparse-checkout set src/my-service tests/my-service

# Partial clone (skip blobs until needed)
git clone --filter=blob:none <url>

# Shallow clone (limited history)
git clone --depth=1 <url>
git fetch --deepen=10    # get more history later

# Enable filesystem monitor for large repos
git config core.fsmonitor true
git config core.untrackedcache true

# Run background maintenance
git maintenance start

# Commit graph for faster log/merge-base
git commit-graph write --reachable

Patches & Selective Transfer

# Create patch files from commits
git format-patch main..feature -o patches/

# Apply patches
git am patches/*.patch

# Apply a diff as patch (without commit metadata)
git diff main..feature -- src/ | git apply

# Create a bundle (portable repo snapshot)
git bundle create repo.bundle --all
git clone repo.bundle restored-repo

# Archive a specific ref
git archive --format=zip -o release.zip HEAD src/

Hooks & Automation

# Share hooks via core.hooksPath (team-wide)
git config core.hooksPath .githooks

# Pre-commit: lint staged files only
# .githooks/pre-commit
#!/bin/sh
git diff --cached --name-only --diff-filter=d | grep '\.cs$' | xargs dotnet format --include

# Commit-msg: enforce conventional commits
# .githooks/commit-msg
#!/bin/sh
if ! grep -qE "^(feat|fix|build|chore|docs|style|refactor|test)\(.+\): .+" "$1"; then
  echo "Commit message must follow: type(scope): description"
  exit 1
fi

Rerere (Reuse Recorded Resolution)

# Enable rerere globally (remember conflict resolutions)
git config --global rerere.enabled true

# After resolving a conflict, Git remembers the resolution
# Next time the same conflict occurs, it's resolved automatically

# Review recorded resolutions
git rerere status
git rerere diff

Anti-Patterns

Troubleshooting Checklist

Advanced Reference

For in-depth coverage of specific topics, load references/advanced-topics.md. Topics include:

• Git internals (object model, packfiles, refs)
• git filter-repo for history surgery
• Signing commits and tags with GPG/SSH
• Git LFS setup and migration
• Monorepo strategies (sparse-checkout, worktrees, CODEOWNERS)
• Advanced merge strategies and custom merge drivers
• Git notes for metadata without changing history
• Shallow clone workflows for CI/CD
• Multi-remote workflows (fork + upstream)