Beginner

# Create a fresh directory for this example
mkdir my-project
# => Creates directory my-project/ in the current working directory

cd my-project
# => Working directory is now my-project/

git init
# => Initialized empty Git repository in /home/user/my-project/.git/
# => Creates hidden .git/ folder containing: HEAD, config, objects/, refs/

ls -la
# => total 0
# => drwxr-xr-x  3 user  staff   96 Mar 20 10:00 .
# => drwxr-xr-x 10 user  staff  320 Mar 20 10:00 ..
# => drwxr-xr-x  9 user  staff  288 Mar 20 10:00 .git

ls .git/
# => HEAD        branches/   config      description hooks/
# => info/       objects/    refs/
# => HEAD contains: ref: refs/heads/main (points to default branch)

# Set identity globally (applies to all repos on this machine)
git config --global user.name "Alice Smith"
# => Writes to ~/.gitconfig under [user] section
# => name = Alice Smith

git config --global user.email "alice@example.com"
# => Writes to ~/.gitconfig under [user] section
# => email = alice@example.com

# Verify the configuration was saved
git config --global user.name
# => Alice Smith

git config --global user.email
# => alice@example.com

# View the full global config
git config --global --list
# => user.name=Alice Smith
# => user.email=alice@example.com
# => core.editor=vim  (or whatever default editor is set)

# Start from an initialized empty repo (from Example 1)
# Working directory: my-project/

git status
# => On branch main
# => No commits yet
# => nothing to commit (create/copy files and use "git add" to track)

# Create a file
echo "# My Project" > README.md
# => Creates README.md with content: # My Project

git status
# => On branch main
# => No commits yet
# =>
# => Untracked files:
# =>   (use "git add <file>..." to include in what will be committed)
# =>         README.md
# =>
# => nothing added to commit but untracked files present (use "git add" to track)
# => Status: README.md is untracked — Git sees it but ignores it

# Continuing from Example 3: README.md is untracked
echo "# My Project" > README.md
# => README.md contains: # My Project (untracked)

echo "console.log('hello');" > app.js
# => app.js contains one line (untracked)

# Stage only README.md (selective staging)
git add README.md
# => README.md moves from "untracked" to "staged"
# => app.js remains untracked

git status
# => On branch main
# => No commits yet
# =>
# => Changes to be committed:
# =>   (use "git rm --cached <file>..." to unstage)
# =>         new file:   README.md    ← staged
# =>
# => Untracked files:
# =>   (use "git add <file>..." to include in what will be committed)
# =>         app.js                   ← still untracked

# Stage everything at once with dot notation
git add .
# => Stages all untracked and modified files in current directory
# => app.js is now staged too

git status
# => Changes to be committed:
# =>         new file:   README.md
# =>         new file:   app.js

# Assume README.md and app.js are staged (from Example 4)
git commit -m "Initial commit: add README and app entry point"
# => [main (root-commit) a1b2c3d] Initial commit: add README and app entry point
# => 2 files changed, 2 insertions(+)
# => create mode 100644 README.md
# => create mode 100644 app.js
# =>
# => Breakdown of output:
# => a1b2c3d = abbreviated SHA-1 hash (unique commit identifier)
# => root-commit = this is the very first commit (no parent)
# => 2 files changed, 2 insertions(+) = summary of diff

git status
# => On branch main
# => nothing to commit, working tree clean
# => Working directory now matches the committed snapshot

# Make a few commits to generate history
echo "v1.0" > version.txt && git add . && git commit -m "feat: add version file"
# => [main b2c3d4e] feat: add version file

echo "v1.1" > version.txt && git add . && git commit -m "feat: bump version to 1.1"
# => [main c3d4e5f] feat: bump version to 1.1

# View full history
git log
# => commit c3d4e5f... (HEAD -> main)
# => Author: Alice Smith <alice@example.com>
# => Date:   Thu Mar 20 10:05:00 2026 +0700
# =>
# =>     feat: bump version to 1.1
# =>
# => commit b2c3d4e...
# => Author: Alice Smith <alice@example.com>
# => Date:   Thu Mar 20 10:04:00 2026 +0700
# =>
# =>     feat: add version file
# =>
# => commit a1b2c3d...
# => Author: Alice Smith <alice@example.com>
# => Date:   Thu Mar 20 10:00:00 2026 +0700
# =>
# =>     Initial commit: add README and app entry point

# Compact one-line format
git log --oneline
# => c3d4e5f (HEAD -> main) feat: bump version to 1.1
# => b2c3d4e feat: add version file
# => a1b2c3d Initial commit: add README and app entry point

# Extended log with decorations, graph, and relative dates
git log --oneline --graph --decorate --all
# => * c3d4e5f (HEAD -> main) feat: bump version to 1.1
# => * b2c3d4e feat: add version file
# => * a1b2c3d Initial commit: add README and app entry point
# =>
# => --graph: draws * for each commit, / and \ for branches
# => --decorate: shows branch/tag labels in parentheses
# => --all: includes all branches and remotes (not just current)

# Custom format: hash | date | author | subject
git log --pretty=format:"%h | %ad | %an | %s" --date=short
# => c3d4e5f | 2026-03-20 | Alice Smith | feat: bump version to 1.1
# => b2c3d4e | 2026-03-20 | Alice Smith | feat: add version file
# => a1b2c3d | 2026-03-20 | Alice Smith | Initial commit: add README and app entry point
# =>
# => %h = abbreviated hash, %ad = author date, %an = author name, %s = subject

# Limit to last 2 commits
git log -2 --oneline
# => c3d4e5f feat: bump version to 1.1
# => b2c3d4e feat: add version file

# Show the most recent commit (HEAD)
git show HEAD
# => commit c3d4e5f... (HEAD -> main)
# => Author: Alice Smith <alice@example.com>
# => Date:   Thu Mar 20 10:05:00 2026 +0700
# =>
# =>     feat: bump version to 1.1
# =>
# => diff --git a/version.txt b/version.txt
# => index abc1234..def5678 100644
# => --- a/version.txt      ← old version
# => +++ b/version.txt      ← new version
# => @@ -1 +1 @@
# => -v1.0                  ← line removed
# => +v1.1                  ← line added

# Show a specific commit by its abbreviated hash
git show a1b2c3d
# => (shows the initial commit diff — all lines are additions)
# => +++ b/README.md
# => @@ -0,0 +1 @@
# => +# My Project

# Show only commit metadata without the diff
git show --stat HEAD
# => commit c3d4e5f...
# => feat: bump version to 1.1
# =>  version.txt | 2 +-
# =>  1 file changed, 1 insertion(+), 1 deletion(-)

# Start clean, then make a change
echo "# My Project" > README.md && git add . && git commit -m "init"
# => [main a1b2c3d] init

# Modify the file (but don't stage yet)
echo "# My Project - Updated" > README.md
# => README.md now contains: # My Project - Updated

# See unstaged changes (working dir vs staging area)
git diff
# => diff --git a/README.md b/README.md
# => --- a/README.md     ← staged/last-committed version
# => +++ b/README.md     ← working directory version
# => @@ -1 +1 @@
# => -# My Project
# => +# My Project - Updated

# Stage the change
git add README.md
# => README.md is now staged

# git diff now shows nothing (working dir matches staging area)
git diff
# => (no output — working dir matches staging area)

# See staged changes (staging area vs last commit)
git diff --staged
# => diff --git a/README.md b/README.md
# => --- a/README.md     ← committed version
# => +++ b/README.md     ← staged version
# => @@ -1 +1 @@
# => -# My Project
# => +# My Project - Updated

# Create typical project artifacts that should NOT be committed
mkdir node_modules && touch node_modules/lodash.js
# => Simulates npm dependencies (often 50k+ files)

echo "SECRET_KEY=abc123" > .env
# => .env contains sensitive credentials — never commit this

touch debug.log
# => Log file generated at runtime

git status
# => Untracked files:
# =>   .env
# =>   debug.log
# =>   node_modules/
# => All three appear — Git wants to track them

# Create .gitignore to exclude them
cat > .gitignore << 'EOF'
# Dependencies
node_modules/

# Environment variables (NEVER commit secrets)
.env
.env.local
.env.*.local

# Logs
*.log

# Build output
dist/
build/
EOF
# => .gitignore is now created with exclusion rules

git status
# => Untracked files:
# =>   .gitignore
# => node_modules/, .env, debug.log are all hidden — not listed

git add .gitignore && git commit -m "chore: add .gitignore"
# => [main b2c3d4e] chore: add .gitignore
# => .gitignore itself IS tracked so the rules are shared with the team

# Start with a committed file
echo "version = 1.0" > config.txt
git add config.txt && git commit -m "add config"
# => [main a1b2c3d] add config

# Make an unwanted change
echo "BROKEN CONFIG!!!" > config.txt
# => config.txt is now corrupted

git status
# => Changes not staged for commit:
# =>         modified:   config.txt
# => Git sees the modification but has not staged it

# Discard the working directory change
git restore config.txt
# => config.txt is restored to last committed version
# => WARNING: This discards changes permanently — no undo

cat config.txt
# => version = 1.0
# => File is back to the committed state

git status
# => nothing to commit, working tree clean
# => Working directory matches the repository

# Stage two files together
echo "feature code" > feature.js
echo "debug only" > debug-helper.js
git add feature.js debug-helper.js
# => Both files are staged

git status
# => Changes to be committed:
# =>         new file:   debug-helper.js   ← should not be in this commit
# =>         new file:   feature.js

# Remove debug-helper.js from staging (keep working directory change)
git restore --staged debug-helper.js
# => debug-helper.js moves from "staged" back to "untracked"
# => The file content on disk is unchanged

git status
# => Changes to be committed:
# =>         new file:   feature.js        ← only feature.js staged now
# =>
# => Untracked files:
# =>         debug-helper.js               ← still on disk, not staged

git commit -m "feat: add feature"
# => [main b2c3d4e] feat: add feature
# => 1 file changed (only feature.js committed, debug-helper.js excluded)

# Starting from a repo with commits on main
git log --oneline
# => c3d4e5f (HEAD -> main) feat: initial setup

# Create a new branch (does not switch to it)
git branch feature/login
# => Creates branch pointer at current commit (c3d4e5f)
# => HEAD still points to main

# List all local branches
git branch
# =>   feature/login
# => * main              ← asterisk marks current branch (HEAD)

# List branches with last commit info
git branch -v
# =>   feature/login c3d4e5f feat: initial setup
# => * main          c3d4e5f feat: initial setup
# => Both branches point to the same commit — no divergence yet

# List all branches including remote tracking branches
git branch -a
# =>   feature/login
# => * main
# => (no remotes yet — remote branches show as remotes/origin/main)

# Continuing from Example 13: branches main and feature/login exist

# Switch to the feature branch
git switch feature/login
# => Switched to branch 'feature/login'
# => Working directory now reflects feature/login's tip commit

git branch
# =>   main
# => * feature/login   ← asterisk moved here

# Make a commit on feature/login
echo "login function" > login.js
git add login.js
git commit -m "feat: add login function"
# => [feature/login d4e5f6a] feat: add login function
# => login.js exists only on feature/login, not on main

# Switch back to main
git switch main
# => Switched to branch 'main'
# => login.js disappears from working directory (it only exists on feature/login)

ls
# => README.md  app.js  version.txt
# => login.js is NOT here — it belongs to feature/login branch only

git switch feature/login
# => Switched to branch 'feature/login'
# => login.js reappears
ls
# => README.md  app.js  login.js  version.txt

# Create and immediately switch to a new branch
git switch -c bugfix/null-pointer
# => Switched to a new branch 'bugfix/null-pointer'
# => Equivalent to: git branch bugfix/null-pointer && git switch bugfix/null-pointer

git branch
# => * bugfix/null-pointer   ← active
# =>   feature/login
# =>   main

# Make a fix commit
echo "null check added" > fix.js
git add fix.js && git commit -m "fix: add null pointer check"
# => [bugfix/null-pointer e5f6a7b] fix: add null pointer check

# Switch back to main without the fix
git switch main
# => Switched to branch 'main'

ls fix.js 2>/dev/null || echo "fix.js does not exist on main"
# => fix.js does not exist on main
# => Confirms: fix.js is isolated to bugfix/null-pointer branch

# Clone a public repository (uses HTTPS)
git clone https://github.com/example/demo-repo.git
# => Cloning into 'demo-repo'...
# => remote: Counting objects: 150, done.
# => remote: Compressing objects: 100% (80/80), done.
# => Receiving objects: 100% (150/150), 45.00 KiB
# => Resolving deltas: 100% (30/30), done.
# => Creates directory demo-repo/ with full history

cd demo-repo
# => Working directory is now demo-repo/

# Clone into a custom directory name
git clone https://github.com/example/demo-repo.git my-copy
# => Clones into my-copy/ instead of demo-repo/

# Verify remote was configured automatically
git remote -v
# => origin  https://github.com/example/demo-repo.git (fetch)
# => origin  https://github.com/example/demo-repo.git (push)
# => 'origin' is the conventional name for the primary remote

# In a cloned repository from Example 16

# List remotes (short form)
git remote
# => origin
# => One remote named 'origin' configured

# List remotes with URLs
git remote -v
# => origin  https://github.com/example/demo-repo.git (fetch)
# => origin  https://github.com/example/demo-repo.git (push)
# => fetch URL: where git fetch/pull downloads from
# => push URL: where git push sends to (usually the same)

# Show detailed info about origin
git remote show origin
# => * remote origin
# =>   Fetch URL: https://github.com/example/demo-repo.git
# =>   Push  URL: https://github.com/example/demo-repo.git
# =>   HEAD branch: main
# =>   Remote branches:
# =>     main tracked
# =>     develop tracked
# =>   Local branch configured for 'git pull':
# =>     main merges with remote main

# Add a second remote (common when forking)
git remote add upstream https://github.com/original/demo-repo.git
# => upstream remote added — points to the original (un-forked) repo

git remote -v
# => origin    https://github.com/example/demo-repo.git (fetch)
# => origin    https://github.com/example/demo-repo.git (push)
# => upstream  https://github.com/original/demo-repo.git (fetch)
# => upstream  https://github.com/original/demo-repo.git (push)

# In a local repo with commits ahead of remote
git log --oneline
# => d4e5f6a (HEAD -> main) feat: add login
# => c3d4e5f (origin/main) initial setup
# => HEAD is ahead of origin/main by 1 commit

# Push main branch to origin
git push origin main
# => Enumerating objects: 3, done.
# => Counting objects: 100% (3/3), done.
# => Writing objects: 100% (2/2), 230 bytes
# => To https://github.com/example/demo-repo.git
# =>    c3d4e5f..d4e5f6a  main -> main
# => Remote now has commit d4e5f6a

# Set upstream tracking (first push of new branch)
git switch -c feature/payments
git commit --allow-empty -m "start payments feature"
# => [feature/payments e5f6a7b] start payments feature

git push -u origin feature/payments
# => Branch 'feature/payments' set up to track remote branch 'feature/payments' from 'origin'.
# => To https://github.com/example/demo-repo.git
# =>  * [new branch]  feature/payments -> feature/payments
# => -u sets upstream: future 'git push' (no args) pushes this branch

# After -u is set, bare 'git push' works
git push
# => Pushes feature/payments to origin/feature/payments automatically

# Simulate a remote having new commits (run by a teammate)
# Your local state:
git log --oneline
# => d4e5f6a (HEAD -> main, origin/main) feat: add login
# => c3d4e5f initial setup

# Remote has received a new commit (teammate pushed)
# Your remote tracking refs are stale

git fetch origin
# => remote: Enumerating objects: 3, done.
# => remote: Counting objects: 100% (3/3), done.
# => From https://github.com/example/demo-repo.git
# =>    d4e5f6a..f6a7b8c  main -> origin/main
# => origin/main updated — local main branch unchanged

git log --oneline --all
# => f6a7b8c (origin/main) feat: teammate's change    ← remote
# => d4e5f6a (HEAD -> main) feat: add login            ← local
# => c3d4e5f initial setup
# => Local main is behind origin/main by 1 commit

git diff main origin/main
# => Shows exactly what changed in teammate's commit
# => Review before merging — git fetch enables informed decisions

# Local main is behind origin/main by 1 commit (from Example 19)
git log --oneline
# => d4e5f6a (HEAD -> main) feat: add login
# => c3d4e5f initial setup

git pull origin main
# => From https://github.com/example/demo-repo.git
# =>  * branch            main       -> FETCH_HEAD
# => Updating d4e5f6a..f6a7b8c
# => Fast-forward            ← no divergence, so merge is a simple pointer advance
# =>  teammate-feature.js | 1 +
# =>  1 file changed, 1 insertion(+)

git log --oneline
# => f6a7b8c (HEAD -> main, origin/main) feat: teammate's change
# => d4e5f6a feat: add login
# => c3d4e5f initial setup
# => Local main now matches origin/main

# Pull with rebase (keeps history linear)
git pull --rebase origin main
# => Rebases local commits on top of fetched commits
# => Produces cleaner history than merge-based pull
# => Preferred by teams following linear history conventions

# Show what HEAD currently points to
cat .git/HEAD
# => ref: refs/heads/main
# => HEAD points to main branch (indirect reference)

# Show the commit HEAD resolves to
git rev-parse HEAD
# => c3d4e5f7a8b9d0e1f2a3b4c5d6e7f8a9b0c1d2e3
# => Full SHA-1 of the current commit

# HEAD~ notation: navigate backwards
git log --oneline
# => c3d4e5f (HEAD -> main) add tests
# => b2c3d4e add login
# => a1b2c3d init

git show HEAD~1 --stat
# => commit b2c3d4e
# => add login
# => login.js | 1 +
# => HEAD~1 = one commit before HEAD (parent)

git show HEAD~2 --stat
# => commit a1b2c3d
# => init
# => HEAD~2 = two commits before HEAD (grandparent)

# HEAD^ is equivalent to HEAD~1 (one parent)
git rev-parse HEAD^
# => b2c3d4e...   ← same as HEAD~1

# Start with a tracked file
echo "old content" > obsolete.txt
git add obsolete.txt && git commit -m "add obsolete file"
# => [main a1b2c3d] add obsolete file

# Remove the file the Git-aware way
git rm obsolete.txt
# => rm 'obsolete.txt'
# => File deleted from disk AND deletion staged in one command

ls obsolete.txt 2>/dev/null || echo "File deleted from disk"
# => File deleted from disk

git status
# => Changes to be committed:
# =>         deleted:   obsolete.txt   ← deletion is staged, ready to commit

git commit -m "chore: remove obsolete file"
# => [main b2c3d4e] chore: remove obsolete file

# Remove from index only (keep file on disk — useful for accidental git add)
echo "should not be tracked" > local-notes.txt
git add local-notes.txt
# => Oops — staged accidentally

git rm --cached local-notes.txt
# => rm 'local-notes.txt'
# => File remains on disk, removed from staging/tracking only
# => Add local-notes.txt to .gitignore to prevent re-adding

# Start with a tracked file
echo "server logic" > server.js
git add server.js && git commit -m "add server"
# => [main a1b2c3d] add server

# Rename using git mv
git mv server.js app-server.js
# => Renames file on disk AND stages the rename in one step
# => Equivalent to: mv server.js app-server.js && git add app-server.js && git rm server.js

git status
# => Changes to be committed:
# =>         renamed:    server.js -> app-server.js   ← explicit rename record

git commit -m "refactor: rename server.js to app-server.js"
# => [main b2c3d4e] refactor: rename server.js to app-server.js

# Move file into a subdirectory
mkdir src/
git mv app-server.js src/app-server.js
# => Moves file into src/ subdirectory

git status
# => Changes to be committed:
# =>         renamed:    app-server.js -> src/app-server.js

git commit -m "refactor: move server into src/"
# => [main c3d4e5f] refactor: move server into src/

# Repository with multiple commits touching different files
git log --oneline
# => e5f6a7b fix: update config validation
# => d4e5f6a feat: add user model
# => c3d4e5f feat: add config loader
# => b2c3d4e chore: initial setup

# Show only commits that touched config.js
git log --oneline -- config.js
# => e5f6a7b fix: update config validation
# => c3d4e5f feat: add config loader
# => Only 2 of 4 commits touched config.js

# See the actual changes made to config.js across its history
git log -p -- config.js
# => commit e5f6a7b
# =>     fix: update config validation
# => diff --git a/config.js b/config.js
# => -  timeout: 30    ← old value
# => +  timeout: 60    ← new value
# =>
# => commit c3d4e5f
# =>     feat: add config loader
# => diff --git a/config.js b/config.js
# => +  const config = require('./config')   ← added

# Follow renames (-- follow tracks file across renames)
git log --follow --oneline -- src/app-server.js
# => c3d4e5f refactor: move server into src/
# => b2c3d4e refactor: rename server.js to app-server.js
# => a1b2c3d add server
# => --follow traverses rename history to show all commits

# Branches: main and feature/old-feature (already merged)
git branch
# =>   feature/old-feature
# => * main

# Delete a merged branch (safe delete)
git branch -d feature/old-feature
# => Deleted branch feature/old-feature (was a1b2c3d).
# => -d only deletes if branch is fully merged into current branch

# Attempt to delete an unmerged branch with -d (fails)
git switch -c feature/wip
git commit --allow-empty -m "work in progress"
git switch main

git branch -d feature/wip
# => error: The branch 'feature/wip' is not fully merged.
# => If you are sure you want to delete it, run 'git branch -D feature/wip'.
# => Git protects unmerged work

# Force delete unmerged branch (use with caution)
git branch -D feature/wip
# => Deleted branch feature/wip (was b2c3d4e).
# => WARNING: Commits on feature/wip are now orphaned
# => They will be garbage collected after ~30 days

# Delete a remote branch
git push origin --delete feature/old-feature
# => To https://github.com/example/repo.git
# =>  - [deleted]         feature/old-feature
# => Removes the branch from the remote repository

# Setup: main has 1 commit, feature branch has 1 more on top
git log --oneline --all
# => b2c3d4e (HEAD -> feature/greet) feat: add greeting
# => a1b2c3d (main) init
# => feature/greet is ahead of main — no divergence

# Switch to main and merge
git switch main
# => Switched to branch 'main'

git merge feature/greet
# => Updating a1b2c3d..b2c3d4e
# => Fast-forward              ← no merge commit created
# =>  greeting.js | 1 +
# =>  1 file changed, 1 insertion(+)

git log --oneline
# => b2c3d4e (HEAD -> main, feature/greet) feat: add greeting
# => a1b2c3d init
# => main pointer simply moved forward to b2c3d4e

# Force a merge commit even for fast-forward (preserves branch history)
git merge --no-ff feature/greet
# => Merge branch 'feature/greet'
# => Creates a merge commit even when fast-forward is possible
# => Useful for preserving the fact that a feature branch existed

# Create a mix of file states
echo "tracked file" > tracked.txt
git add tracked.txt && git commit -m "init"
# => File is committed (clean)

echo "modified" >> tracked.txt
# => tracked.txt is now modified (unstaged)

echo "new file" > new-staged.txt
git add new-staged.txt
# => new-staged.txt is staged

echo "totally new" > untracked.txt
# => untracked.txt is untracked

# Standard verbose status
git status
# => On branch main
# => Changes to be committed:
# =>   new file:   new-staged.txt     ← staged new file
# => Changes not staged for commit:
# =>   modified:   tracked.txt        ← modified but not staged
# => Untracked files:
# =>   untracked.txt                  ← not tracked at all

# Short format (2-character status codes)
git status --short
# => A  new-staged.txt   ← A = Added (staged)
# =>  M tracked.txt      ← M in right column = Modified (unstaged)
# => ?? untracked.txt    ← ?? = Untracked
# =>
# => First column: staging area status
# => Second column: working directory status
# => Common codes: A=Added, M=Modified, D=Deleted, R=Renamed, ?=Untracked

# Show branch info in short format
git status -sb
# => ## main...origin/main
# => A  new-staged.txt
# =>  M tracked.txt
# => ?? untracked.txt
# => -b adds branch tracking info at top

# Repository with diverse commit history
# Show commits by a specific author
git log --oneline --author="Alice"
# => e5f6a7b feat: add user profile
# => c3d4e5f fix: null pointer in login
# => Filters to only Alice's commits (partial name match)

# Show commits from the last 7 days
git log --oneline --since="7 days ago"
# => f6a7b8c feat: add payment gateway
# => e5f6a7b feat: add user profile
# => Only commits from the past week

# Show commits with message matching a pattern
git log --oneline --grep="feat:"
# => f6a7b8c feat: add payment gateway
# => e5f6a7b feat: add user profile
# => d4e5f6a feat: add login
# => Only commits whose message contains "feat:"

# Search for commits that added or removed a specific string
git log --oneline -S "connectTimeout"
# => c3d4e5f feat: add config loader
# => Finds the commit that first introduced "connectTimeout" in any file
# => Useful for tracing when a function/variable was added

# Combine filters
git log --oneline --author="Alice" --since="30 days ago" --grep="fix:"
# => Commits by Alice, in the last 30 days, with "fix:" in message
# => Filters compose with AND logic