Git

# Identity (required before first commit)
git config --global user.name "Your Name"
git config --global user.email "your@email.com"
 
# Default editor
git config --global core.editor "code --wait"
 
# View all active configuration
git config --list --show-origin
 
# Useful aliases
git config --global alias.st status
git config --global alias.co checkout
git config --global alias.br branch
git config --global alias.lg "log --oneline --graph --all --decorate"

# New repository
git init my-project
cd my-project
 
# Clone existing
git clone https://github.com/user/repo.git
 
# Clone only latest revision (fast for CI)
git clone --depth 1 https://github.com/user/repo.git
 
# Clone specific branch
git clone -b develop https://github.com/user/repo.git

# View current status
git status
git status -s          # short format
 
# Add files to staging
git add file.ts                # specific file
git add src/                   # entire directory
git add -A                     # everything (new, modified, deleted)
git add -p                     # interactive: choose individual hunks
 
# Remove from staging (without losing changes)
git restore --staged file.ts   # Git 2.23+
git reset HEAD file.ts         # classic way
 
# Commit
git commit -m "feat: add user authentication"
git commit -am "fix: typo in header"   # add + commit (tracked files only)
git commit --amend                      # modify last commit
git commit --amend --no-edit            # same message, add forgotten files
git commit --allow-empty -m "trigger CI"  # empty commit

# List branches
git branch              # local
git branch -r           # remote
git branch -a           # all
git branch -v           # with last commit
 
# Create and switch
git branch feature/login
git checkout feature/login
git checkout -b feature/login          # create + switch in one step
git switch -c feature/login            # Git 2.23+ (preferred)
 
# Rename
git branch -m old-name new-name
git branch -m new-name                 # rename current branch
 
# Delete
git branch -d feature/login            # only if already merged
git branch -D feature/login            # force delete
git push origin --delete feature/login # delete remote branch

# Merge: incorporate changes from another branch
git checkout main
git merge feature/login                # merge commit (no fast-forward if diverged)
git merge --no-ff feature/login        # force merge commit (useful for history)
git merge --squash feature/login       # squash all commits into one
git merge --abort                      # cancel merge with conflicts
 
# Rebase: rewrite history on top of another branch
git checkout feature/login
git rebase main                        # move commits on top of main
git rebase -i HEAD~3                   # interactive rebase (last 3 commits)
git rebase --abort                     # cancel rebase
git rebase --continue                  # after resolving conflicts
 
# Interactive rebase — options per commit:
# pick   = use commit as-is
# reword = change message
# edit   = pause to modify
# squash = combine with previous
# fixup  = combine without message
# drop   = delete commit

# Basic log
git log
git log --oneline                      # one line per commit
git log --oneline --graph --all        # visual graph of all branches
git log --since="2 weeks ago"
git log --author="name"
git log -- file.ts                     # history of a file
git log -p -- file.ts                  # with diffs
 
# Search history
git log --grep="fix"                   # commits whose message contains "fix"
git log -S "functionName"              # commits that added/removed that text
git log -G "regex"                     # regex search in diffs
 
# Differences
git diff                               # working tree vs staging
git diff --staged                      # staging vs last commit
git diff main..feature/login           # between two branches
git diff HEAD~3..HEAD                  # last 3 commits
git diff --stat                        # summary of changed files
git diff --name-only                   # file names only
 
# Who wrote each line
git blame file.ts
git blame -L 10,20 file.ts            # only lines 10-20
 
# Show a specific commit
git show abc1234
git show HEAD~2:file.ts               # file at a previous commit

# Save changes temporarily
git stash                              # stash with automatic message
git stash push -m "work in progress"   # with descriptive message
git stash push -p                      # interactive stash (choose hunks)
git stash --include-untracked          # include new files
 
# Recover
git stash pop                          # apply and remove from stash
git stash apply                        # apply without removing
git stash apply stash@{2}             # apply a specific stash
 
# Manage
git stash list                         # view all stashes
git stash show -p stash@{0}           # view stash contents
git stash drop stash@{0}              # delete a stash
git stash clear                        # delete all

# View configured remotes
git remote -v
 
# Add remote
git remote add upstream https://github.com/original/repo.git
 
# Fetch changes without merge
git fetch origin
git fetch --all                        # from all remotes
git fetch --prune                      # remove refs to deleted remote branches
 
# Fetch and merge
git pull                               # fetch + merge
git pull --rebase                      # fetch + rebase (linear history)
git pull --rebase --autostash          # automatic stash before rebase
 
# Push changes
git push origin main
git push -u origin feature/login       # push + set upstream
git push --force-with-lease            # safe force push (verifies no one else pushed)
git push origin --tags                 # push all tags

# Discard changes in working tree
git restore file.ts                    # Git 2.23+
git checkout -- file.ts                # classic way
 
# Undo last commit (keep changes)
git reset --soft HEAD~1                # changes stay in staging
git reset --mixed HEAD~1               # changes stay in working tree (default)
git reset --hard HEAD~1                # ⚠️ delete changes completely
 
# Revert a commit (creates new inverse commit — safe for shared branches)
git revert abc1234
git revert HEAD                        # revert last commit
git revert --no-commit HEAD~3..HEAD    # revert range without individual commits
 
# Recover "lost" commits
git reflog                             # history of HEAD movements
git checkout abc1234                   # go to a reflog commit
git branch recovery abc1234            # create branch from recovered commit

# Create
git tag v1.0.0                         # lightweight tag
git tag -a v1.0.0 -m "Release 1.0.0"  # annotated tag (recommended)
git tag -a v1.0.0 abc1234              # tag at specific commit
 
# List and view
git tag
git tag -l "v1.*"                      # filter by pattern
git show v1.0.0
 
# Publish
git push origin v1.0.0                 # one tag
git push origin --tags                 # all tags
 
# Delete
git tag -d v1.0.0                      # local
git push origin --delete v1.0.0        # remote

# Apply a specific commit to current branch
git cherry-pick abc1234
git cherry-pick abc1234 def5678        # multiple commits
git cherry-pick --no-commit abc1234    # apply without committing
 
# Find the commit that introduced a bug (binary search)
git bisect start
git bisect bad                         # current commit has the bug
git bisect good v1.0.0                 # this commit was fine
# Git takes you to intermediate commits — mark good/bad until you find the culprit
git bisect reset                       # return to normal state
 
# Automatic bisect with a test script
git bisect start HEAD v1.0.0
git bisect run npm test

# Remove untracked files
git clean -n                           # dry run (see what would be deleted)
git clean -fd                          # delete files and directories
git clean -fdx                         # include files ignored by .gitignore
 
# Optimize repository
git gc                                 # garbage collection
git gc --aggressive                    # more aggressive compression
 
# Verify integrity
git fsck

# Common patterns
node_modules/
dist/
.env
.env.local
*.log
.DS_Store
.next/
coverage/