Why worktrees enable parallel work in Git - Visual Breakdown

Process Flow - Why worktrees enable parallel work

Create main repo

↓

Add worktree 1

→Worktree 1: branch A

↓

Add worktree 2

→Worktree 2: branch B

↓

Make changes in worktree 1

↓

Make changes in worktree 2

↓

Commit independently in each worktree

↓

Parallel work enabled

Worktrees let you have multiple working folders linked to the same repo, each on different branches, so you can work on them at the same time without switching.

Execution Sample

Git

git clone repo.git
cd repo

git worktree add ../feature1 feature1

git worktree add ../feature2 feature2

This creates two separate folders for branches feature1 and feature2 so you can work on both simultaneously.

Process Table

Step	Command	Action	Result
1	git clone repo.git	Clone repository	Local repo created with main branch
2	cd repo	Change directory	Inside main repo folder
3	git worktree add ../feature1 feature1	Add worktree for branch feature1	New folder ../feature1 with branch feature1 checked out
4	git worktree add ../feature2 feature2	Add worktree for branch feature2	New folder ../feature2 with branch feature2 checked out
5	Make changes in ../feature1	Edit files	Changes isolated to feature1 worktree
6	Make changes in ../feature2	Edit files	Changes isolated to feature2 worktree
7	Commit in ../feature1	Commit changes	Commit saved on feature1 branch
8	Commit in ../feature2	Commit changes	Commit saved on feature2 branch
9	Worktrees allow parallel work	No branch switching needed	Multiple branches worked on simultaneously

💡 Parallel work enabled because each worktree has its own working directory and branch checkout

Status Tracker

Variable	Start	After Step 3	After Step 4	After Step 7	After Step 8
feature1 branch state	Not checked out	Checked out in ../feature1	Checked out in ../feature1	Committed changes	Committed changes
feature2 branch state	Not checked out	Not checked out	Checked out in ../feature2	No changes	Committed changes
working directories	repo only	repo + ../feature1	repo + ../feature1 + ../feature2	Changes in ../feature1	Changes in ../feature1 and ../feature2

Key Moments - 3 Insights

Why don't we need to switch branches when using worktrees?

Because each worktree folder has its own branch checked out independently, as shown in steps 3 and 4 in the execution_table.

Can changes in one worktree affect the other worktree's files?

No, changes are isolated to each worktree's folder, so edits in ../feature1 do not affect ../feature2, as seen in steps 5 and 6.

How does using worktrees save time compared to switching branches?

Worktrees let you work on multiple branches at once without switching, avoiding the wait and risk of switching branches, shown by independent commits in steps 7 and 8.

Visual Quiz - 3 Questions

Look at the execution_table at step 4. What does the command 'git worktree add ../feature2 feature2' do?

A Deletes the main repo folder

B Creates a new folder ../feature2 with branch feature2 checked out

C Switches the current branch to feature2 in the main repo

D Merges feature2 into main branch

💡 Hint

Check the 'Result' column at step 4 in the execution_table

At which step do changes become isolated to the feature1 worktree?

A Step 3

B Step 7

C Step 5

D Step 9

💡 Hint

Look at the 'Action' and 'Result' columns for step 5 in the execution_table

If you did not use worktrees, how would the execution_table change?

A You would see branch switching commands instead of adding worktrees

B You would have multiple folders for each branch by default

C You could commit on multiple branches simultaneously without switching

D The repo would automatically merge branches

💡 Hint

Think about what happens when you work on multiple branches without worktrees

Concept Snapshot

git worktrees let you create multiple working folders linked to the same repo.
Each worktree checks out a different branch.
This allows parallel work without switching branches.
Commands: git worktree add <path> <branch>
Changes and commits in each worktree are isolated.
Worktrees save time and reduce errors when working on multiple features.

Full Transcript

Git worktrees enable parallel work by letting you have multiple folders, each with its own branch checked out. You start by cloning a repo, then add worktrees for different branches. Each worktree acts like a separate workspace. You can edit, commit, and work on different branches at the same time without switching. This isolation avoids conflicts and saves time. The execution table shows cloning, adding worktrees, making changes, and committing independently. Variables track branch states and working directories. Key moments clarify why no branch switching is needed, how changes stay isolated, and how worktrees save time. The quiz tests understanding of commands, isolation, and differences without worktrees.

Practice

1. What is the main benefit of using git worktree for parallel work?

easy

A. It deletes old branches to save space.

B. It automatically merges branches without conflicts.

C. It allows working on multiple branches simultaneously in separate folders.

D. It creates a backup of the entire repository.

Solution

1. Step 1: Understand what git worktree does

   git worktree lets you check out multiple branches at once in different folders without cloning the repo multiple times.

2. Step 2: Compare options with this feature

   Only It allows working on multiple branches simultaneously in separate folders. correctly describes this benefit. Other options describe unrelated or incorrect features.

3. Final Answer:

   It allows working on multiple branches simultaneously in separate folders. -> Option C

4. Quick Check:

   Parallel branch work = It allows working on multiple branches simultaneously in separate folders. [OK]

Hint: Worktrees = multiple branches in separate folders [OK]

Common Mistakes:

• Thinking worktrees merge branches automatically
• Confusing worktrees with backups
• Assuming worktrees delete branches

2. Which command correctly creates a new worktree for branch feature in folder ../feature?

easy

A. git worktree create feature ../feature

B. git worktree add ../feature feature

C. git add worktree ../feature feature

D. git checkout worktree feature ../feature

Solution

1. Step 1: Recall correct syntax for adding a worktree

   The correct syntax is git worktree add <path> <branch>.

2. Step 2: Match options to syntax

   Only git worktree add ../feature feature matches this syntax exactly. Others use wrong commands or order.

3. Final Answer:

   git worktree add ../feature feature -> Option B

4. Quick Check:

   Correct add syntax = git worktree add ../feature feature [OK]

Hint: Use 'git worktree add <path> <branch>' to create worktree [OK]

Common Mistakes:

• Using 'create' instead of 'add'
• Mixing order of arguments
• Using 'git add' or 'git checkout' incorrectly

3. Given these commands executed in a repo:

git worktree add ../feature feature
cd ../feature
git status

What will git status show in the ../feature folder?

medium

A. On branch master, with changes from master branch.

B. Error: not a git repository.

C. Detached HEAD state with no branch.

D. On branch feature, with changes from that branch.

Solution

1. Step 1: Understand what git worktree add ../feature feature does

   This creates a new folder ../feature checked out to the feature branch.

2. Step 2: Check git status in that folder

   Since the folder is a valid worktree on feature branch, git status shows branch feature and its changes.

3. Final Answer:

   On branch feature, with changes from that branch. -> Option D

4. Quick Check:

   Worktree folder branch = feature [OK]

Hint: Worktree folder tracks specified branch, not master [OK]

Common Mistakes:

• Assuming worktree defaults to master branch
• Thinking worktree folder is detached HEAD
• Confusing worktree folder with unrelated repo

4. You ran git worktree add ../dev feature but got an error: fatal: 'feature' is not a commit and a branch 'feature' cannot be created from it. What is the likely cause?

medium

A. The branch 'feature' does not exist in the repo.

B. The folder '../dev' already contains a git repo.

C. You forgot to commit changes before adding worktree.

D. You used 'git worktree create' instead of 'add'.

Solution

1. Step 1: Analyze the error message

   The error says 'feature' is not a commit and branch cannot be created, meaning the branch does not exist.

2. Step 2: Match cause to options

   The branch 'feature' does not exist in the repo. matches this cause. Other options describe unrelated issues or wrong commands.

3. Final Answer:

   The branch 'feature' does not exist in the repo. -> Option A

4. Quick Check:

   Branch must exist before adding worktree [OK]

Hint: Check branch exists before adding worktree [OK]

Common Mistakes:

• Assuming folder conflict causes this error
• Thinking uncommitted changes block worktree add
• Confusing 'add' with 'create' command

5. You want to work on two features in parallel without cloning the repo twice. You create two worktrees:

git worktree add ../feature1 feature1
git worktree add ../feature2 feature2

What is a key advantage of this approach compared to cloning twice?

hard

A. It saves disk space by sharing the same .git data.

B. It automatically syncs changes between branches.

C. It prevents any merge conflicts between branches.

D. It allows pushing both branches with one command.

Solution

1. Step 1: Understand difference between worktrees and cloning

   Worktrees share the same repository data (.git) but have separate working folders, saving disk space.

2. Step 2: Evaluate options

   It saves disk space by sharing the same .git data. correctly states the disk space saving. Other options describe features not provided by worktrees.

3. Final Answer:

   It saves disk space by sharing the same .git data. -> Option A

4. Quick Check:

   Worktrees share repo data, saving space [OK]

Hint: Worktrees share .git data, saving space vs cloning [OK]

Common Mistakes:

• Thinking worktrees auto-sync branches
• Assuming worktrees prevent merge conflicts
• Believing one push updates multiple branches