Claude Command: Compare Worktrees

Your job is to compare files and directories between git worktrees, helping users understand differences in code across branches or worktrees.

Instructions

CRITICAL: Perform the following steps exactly as described:

Current state check: Run git worktree list to show all existing worktrees and their locations

Parse user input: Classify each provided argument:

• No arguments: Interactive mode - ask user what to compare

• --stat : Show summary statistics of differences (files changed, insertions, deletions)

• Worktree path: A path that matches one of the worktree roots from git worktree list

• Branch name: A name that matches a branch in one of the worktrees

• File/directory path: A path within the current worktree to compare

Determine comparison targets (worktrees to compare): a. If user provided worktree paths: Use those as comparison targets b. If user specified branch names: Find the worktrees for those branches from git worktree list

c. If only one worktree exists besides current: Use current and that one as comparison targets d. If multiple worktrees exist and none specified: Present list and ask user which to compare e. If no other worktrees exist: Offer to compare with a branch using git diff

Determine what to compare (files/directories within worktrees): a. If user specified file(s) or directory(ies) paths: Compare ALL of them b. If no specific paths given: Ask user:

• "Compare entire worktree?" or

• "Compare specific files/directories? (enter paths)"

Execute comparison:

For specific files between worktrees:

diff <worktree1>/<path> <worktree2>/<path>

Or for unified diff format:

diff -u <worktree1>/<path> <worktree2>/<path>

For directories between worktrees:

diff -r <worktree1>/<directory> <worktree2>/<directory>

Or for summary only:

diff -rq <worktree1>/<directory> <worktree2>/<directory>

For branch-level comparison (using git diff):

git diff <branch1>..<branch2> -- <path>

Or for stat summary:

git diff --stat <branch1>..<branch2>

For comparing with current working directory:

diff <current-file> <other-worktree>/<file>

Format and present results:

• Show clear header indicating what's being compared

• For large diffs, offer to show summary first

• Highlight significant changes (new files, deleted files, renamed files)

• Provide context about the branches each worktree contains

Comparison Modes

Mode Description Command Pattern

File diff Compare single file between worktrees diff -u <wt1>/file <wt2>/file

Directory diff Compare directories recursively diff -r <wt1>/dir <wt2>/dir

Summary only Show which files differ (no content) diff -rq <wt1>/ <wt2>/

Git diff Use git's diff (branch-based) git diff branch1..branch2 -- path

Stat view Show change statistics git diff --stat branch1..branch2

Worktree Detection

The command finds worktrees using git worktree list :

/home/user/project abc1234 [main] /home/user/project-feature def5678 [feature-x] /home/user/project-hotfix ghi9012 [hotfix-123]

From this output, the command extracts:

• Path: The absolute path to the worktree directory

• Branch: The branch name in brackets (used when user specifies branch name)

Examples

Compare specific file between worktrees:

/git:compare-worktrees src/app.js

Prompts to select which worktree to compare with

Shows diff of src/app.js between current and selected worktree

Compare between two specific worktrees:

/git:compare-worktrees ../project-main ../project-feature src/module.js

Compares src/module.js between the two specified worktrees

Compare multiple files/directories:

/git:compare-worktrees src/app.js src/utils/ package.json

Shows diffs for all three paths between worktrees

Compare entire directories:

/git:compare-worktrees src/

Shows all differences in src/ directory between worktrees

Get summary statistics:

/git:compare-worktrees --stat

Shows which files differ and line counts

Interactive mode:

/git:compare-worktrees

Lists available worktrees

Asks which to compare

Asks for specific paths or entire worktree

Compare with branch worktree by branch name:

/git:compare-worktrees feature-x

Finds worktree for feature-x branch and compares

Compare specific paths between branch worktrees:

/git:compare-worktrees main feature-x src/ tests/

Compares src/ and tests/ directories between main and feature-x worktrees

Output Format

File Comparison Header:

Comparing: src/app.js From: /home/user/project (main) To: /home/user/project-feature (feature-x)

[diff output]

Summary Output:

Worktree Comparison Summary

From: /home/user/project (main) To: /home/user/project-feature (feature-x)

Files only in main:

• src/deprecated.js

Files only in feature-x:

• src/new-feature.js
• src/new-feature.test.js

Files that differ: ~ src/app.js ~ src/utils/helpers.js ~ package.json

Statistics: 3 files changed 2 files added 1 file removed

Common Workflows

Review Feature Changes

See what changed in a feature branch

/git:compare-worktrees --stat /git:compare-worktrees src/components/

Compare Implementations

Compare how two features implemented similar functionality

/git:compare-worktrees ../project-feature-1 ../project-feature-2 src/auth/

Quick File Check

Check if a specific file differs

/git:compare-worktrees package.json

Pre-Merge Review

Review all changes before merging (compare src and tests together)

/git:compare-worktrees --stat /git:compare-worktrees src/ tests/

Both src/ and tests/ directories will be compared

Important Notes

Argument detection: The command auto-detects argument types by comparing them against git worktree list output:

• Paths matching worktree roots → treated as worktrees to compare

• Names matching branches in worktrees → treated as worktrees to compare

• Other paths → treated as files/directories to compare within worktrees

Multiple paths: When multiple file/directory paths are provided, ALL of them are compared between the selected worktrees (not just the first one).

Worktree paths: When specifying worktrees, use the full path or relative path from current directory (e.g., ../project-feature )

Branch vs Worktree: If you specify a branch name, the command looks for a worktree with that branch checked out. If no worktree exists for that branch, it suggests using git diff instead.

Large diffs: For large directories, the command will offer to show a summary first before displaying full diff output.

Binary files: Binary files are detected and reported as "Binary files differ" without showing actual diff.

File permissions: The diff will also show changes in file permissions if they differ.

No worktrees: If no other worktrees exist, the command will explain how to create one and offer to use git diff for branch comparison instead.

Integration with Create Worktree

Use /git:create-worktree first to set up worktrees for comparison:

Create worktrees for comparison

/git:create-worktree feature-x, main

Created: ../project-feature-x and ../project-main

Now compare

/git:compare-worktrees src/

Troubleshooting

"No other worktrees found"

• Create a worktree first with /git:create-worktree <branch>

• Or use git diff for branch-only comparison without worktrees

"Worktree for branch not found"

• The branch may not have a worktree created

• Run git worktree list to see available worktrees

• Create the worktree with /git:create-worktree <branch>

"Path does not exist in worktree"

• The specified file/directory may not exist in one of the worktrees

• This could indicate the file was added/deleted in one branch

• The command will report this in the comparison output