johnlindquist/claude/diff-preview

# Git
git --version
 
# Gemini for AI explanations
pip install google-generativeai
export GEMINI_API_KEY=your_api_key

# Working directory changes
git diff
 
# Staged changes
git diff --staged
git diff --cached
 
# Specific file
git diff path/to/file.ts
 
# Between commits
git diff abc123 def456
 
# Between branches
git diff main feature-branch
git diff main...feature-branch  # Since branch diverged
 
# Show stat summary
git diff --stat
git diff --shortstat
 
# Name only
git diff --name-only
git diff --name-status  # With status (M/A/D)

# Word diff (better for prose)
git diff --word-diff
 
# Color words
git diff --color-words
 
# Ignore whitespace
git diff -w
git diff --ignore-all-space
 
# Context lines
git diff -U10  # 10 lines of context (default 3)
 
# Show function names
git diff --function-context

# Last commit
git diff HEAD~1
 
# Last N commits
git diff HEAD~5
 
# Specific commit range
git diff abc123..def456
 
# What changed in a specific commit
git show abc123

# Get diff and explain
DIFF=$(git diff --staged)
gemini -m pro -o text -e "" "Explain these code changes in plain English:
 
$DIFF
 
Summarize:
1. What was changed
2. Why it might have been changed
3. Any potential issues"

DIFF=$(git diff main...feature-branch)
gemini -m pro -o text -e "" "Analyze the impact of these changes:
 
$DIFF
 
Consider:
1. Breaking changes
2. Performance implications
3. Security considerations
4. Files/systems affected
5. Testing recommendations"

# Review staged changes before commit
git diff --staged | gemini -m pro -o text -e "" "Review this code diff for:
1. Bugs or issues
2. Code style problems
3. Missing error handling
4. Security concerns
 
Provide specific line references if issues found."

DIFF=$(git diff --staged)
gemini -m pro -o text -e "" "Based on this diff, suggest a commit message:
 
$DIFF
 
Use conventional commit format (feat/fix/chore/etc).
First line under 50 chars, then details."

# Summary
git diff main feature-branch --stat
 
# Full diff
git diff main feature-branch
 
# Since branch point
git diff main...feature-branch
 
# Commits unique to feature branch
git log main..feature-branch --oneline

# What files changed between commits
git diff --name-only abc123 def456
 
# What changed in a file
git log -p -- path/to/file.ts
 
# When was a line added
git blame path/to/file.ts

# Preview merge conflicts
git merge --no-commit --no-ff feature-branch
git diff --staged
git merge --abort  # Clean up

#!/bin/bash
# Check staged changes before commit
 
echo "=== Changes to commit ==="
git diff --staged --stat
 
echo ""
echo "=== Detailed diff ==="
git diff --staged
 
echo ""
read -p "Proceed with commit? (y/n) " -n 1 -r
if [[ $REPLY =~ ^[Yy]$ ]]; then
  git commit
fi

# Get full PR diff for review
BASE=${1:-main}
BRANCH=$(git branch --show-current)
 
echo "=== Files changed ==="
git diff $BASE...$BRANCH --name-status
 
echo ""
echo "=== Stats ==="
git diff $BASE...$BRANCH --shortstat
 
echo ""
echo "=== AI Summary ==="
git diff $BASE...$BRANCH | gemini -m pro -o text -e "" "Summarize this PR's changes for a code reviewer. Focus on the intent and key changes."

# Find all changes to a function
git log -p -S "functionName" -- "*.ts"
 
# Find changes mentioning something
git log -p --grep="JIRA-123"