git-analyzer

A lean, dependency-free command-line tool written in Zig that analyzes Git repository history and provides weekly productivity metrics.

Features

• Daily View (Default): Last 30 days with daily breakdown - perfect for recent productivity tracking
• Monthly History: Use --history for long-term trends and monthly aggregation
• Insightful Metrics:
  • Total commits per day/month
  • Lines added and deleted (color-coded)
  • Average commit size
  • Refactoring ratio (lines deleted / lines added)
• Summary Totals: Overall statistics across the entire period
• Color Output: Green for additions, red for deletions (disable with --no-color)
• Large Repository Support: Streaming processing handles millions of commits
• Zero Dependencies: Uses only Zig standard library and shells out to git
• Container-based Build: Supports both Docker and Podman

Requirements

• Git (must be in PATH)
• Docker or Podman (for building)

Building

# Build the tool (creates zig-out/bin/git-insight)
make build

# Or build and run in one command
make run

Usage

# Analyze last 30 days (default daily view)
./zig-out/bin/git-insight

# Monthly history for last year
./zig-out/bin/git-insight --history

# Last 60 days, daily view
./zig-out/bin/git-insight --since="60 days ago"

# Last 2 years, monthly view
./zig-out/bin/git-insight --history --since="2 years ago"

# Disable colors for scripts
./zig-out/bin/git-insight --no-color

# Using make
make run args='--history'
make run args='--since="90 days ago"'

Example Output

Daily View (Default):

Git Insight Daily Report for the last 30 days ago

| Date         | Commits | Lines Added | Lines Deleted | Avg. Commit Size | Refactoring Ratio |
|--------------|---------|-------------|---------------|------------------|-------------------|
| Jul 25, 2025 |       3 | +245        | -12           |               86 |              0.05 |
| Jul 26, 2025 |       8 | +1200       | -350          |              194 |              0.29 |
| Jul 27, 2025 |       5 | +456        | -23           |               96 |              0.05 |
|--------------|---------|-------------|---------------|------------------|-------------------|
| TOTAL        |      16 | +1901       | -385          |              143 |              0.20 |

Monthly History (--history):

Git Insight Monthly History for the last 1 year ago

| Month        | Commits | Lines Added | Lines Deleted | Avg. Commit Size | Refactoring Ratio |
|--------------|---------|-------------|---------------|------------------|-------------------|
| Jan 2025     |      45 | +2150       | -800          |               66 |              0.37 |
| Feb 2025     |      52 | +3200       | -1200         |               85 |              0.38 |
| Mar 2025     |      38 | +1800       | -450          |               59 |              0.25 |
|--------------|---------|-------------|---------------|------------------|-------------------|
| TOTAL        |     135 | +7150       | -2450         |               71 |              0.34 |

Note: In terminals with color support, additions appear in green and deletions in red.

Development

# Launch interactive shell in build container
make shell

# Clean build artifacts
make clean

# Clean everything including Docker image
make clean-all

Architecture

The tool executes git log with specific formatting options and parses the output to calculate metrics. It groups commits by week and computes:

1. Refactoring Ratio: Higher values suggest more code cleanup/refactoring
2. Average Commit Size: Helps identify commit granularity patterns
3. Weekly Trends: Visual representation of development activity

Implementation Details

• Written in Zig 0.13.0
• Uses git log --numstat for accurate line counts
• Handles binary files gracefully (excludes from line counts)
• Week starts on Sunday (configurable in code)
• Single static executable output

Changelog

• v2.0:
  • 🔥 New default: Daily view for last 30 days (much more actionable!)
  • 📊 History mode: --history flag for monthly aggregation
  • 🚀 Large repo support: Fixed StdoutStreamTooLong error with streaming
  • 🎯 Better UX: Daily for recent work, monthly for trends
• v1.1: Added color output, week date ranges, and summary totals
• v1.0: Initial release with basic weekly statistics