robbyt/diff-review

Diff Review via Gemini

Have Gemini review git changes for a second perspective on code quality.

Quick Start

Save diff to project root, have Gemini review, then clean up:

git diff --cached > gemini-review.diff
gemini "Review the code changes at gemini-review.diff for issues. Do not make any changes. Respond with feedback only." --allowed-tools read_file,codebase_investigator,glob,search_file_content,list_directory,write_todos -o text 2>&1
rm gemini-review.diff

Patterns

Staged changes:

git diff --cached > gemini-review.diff
gemini "Review gemini-review.diff for:
1. Bugs or logic errors
2. Security vulnerabilities
3. Style inconsistencies
4. Missing error handling
Do not make any changes. Respond with feedback only." --allowed-tools read_file,codebase_investigator,glob,search_file_content,list_directory,write_todos -o text 2>&1
rm gemini-review.diff

All uncommitted changes:

git diff HEAD > gemini-review.diff
gemini "Review gemini-review.diff. Do not make any changes. Respond with feedback only." --allowed-tools read_file,codebase_investigator,glob,search_file_content,list_directory,write_todos -o text 2>&1
rm gemini-review.diff

Specific commit:

git show abc123 > gemini-review.diff
gemini "Review the commit at gemini-review.diff. Do not make any changes. Respond with feedback only." --allowed-tools read_file,codebase_investigator,glob,search_file_content,list_directory,write_todos -o text 2>&1
rm gemini-review.diff

Focused Reviews

Security focus:

git diff --cached > gemini-review.diff
gemini "Security review of gemini-review.diff. Check for:
- XSS vulnerabilities
- SQL/command injection
- Sensitive data exposure
- Authentication/authorization issues
Do not make any changes. Respond with feedback only." --allowed-tools read_file,codebase_investigator,glob,search_file_content,list_directory,write_todos -o text 2>&1
rm gemini-review.diff

Performance focus:

git diff --cached > gemini-review.diff
gemini "Performance review of gemini-review.diff. Check for:
- Inefficient algorithms
- N+1 queries
- Memory leaks
- Blocking operations
Do not make any changes. Respond with feedback only." --allowed-tools read_file,codebase_investigator,glob,search_file_content,list_directory,write_todos -o text 2>&1
rm gemini-review.diff

With File Context

Ask Gemini to read full files for better context:

git diff --cached > gemini-review.diff
gemini "Review gemini-review.diff. Also read the full files:
- src/auth/login.ts
- src/utils/validate.ts
to understand the broader context. Do not make any changes. Respond with feedback only." --allowed-tools read_file,codebase_investigator,glob,search_file_content,list_directory,write_todos -o text 2>&1
rm gemini-review.diff

Notes

• Gemini must not make any changes, provide feedback ONLY.
• Gemini respects .gitignore - it cannot read files matching gitignore patterns
• Gemini can only read files in the workspace directory (project root)
• Requires dangerouslyDisableSandbox: true for Bash calls
• May take 1-2 minutes for thorough review
• See references/setup.md for troubleshooting