A Rust CLI tool that automatically generates conventional git commit message prefixes by analyzing git diffs. It suggests commit types (feat, fix, docs, style, refactor, test, chore) and auto-detects scopes based on changed file paths, helping developers maintain consistent commit conventions without external dependencies.

Features

Automatic commit type detection - Maps changed files to conventional commit types
Scope auto-detection - Extracts scope names from file paths (e.g., 'auth' from src/auth/login.rs)
Multiple output formats - Short, verbose, compact, and JSON for scripting
Interactive mode - Prompts for confirming/selecting types and scopes
Configuration support - Load custom conventions from .commitlintrc or custom config files
Staged changes support - Analyze both working directory and staged changes

Installation

cargo install git-commit-prefix-gen

Or build from source:

git clone https://github.com/user/git-commit-prefix-gen
cd git-commit-prefix-gen
cargo build --release

Usage

Basic usage

git-commit-prefix-gen

Specify output format

git-commit-prefix-gen --format short      # Default: feat(auth): add login
git-commit-prefix-gen --format verbose    # Detailed output with file list
git-commit-prefix-gen --format compact    # No spaces: feat(auth):add login
git-commit-prefix-gen --format json       # JSON for scripting

Override detected type/scope

git-commit-prefix-gen --type feat --scope api

Analyze staged changes

git-commit-prefix-gen --staged

Interactive mode

git-commit-prefix-gen --interactive

Use custom config file

git-commit-prefix-gen --config .commitlintrc.json

Dry run (no changes)

git-commit-prefix-gen --dry-run

Supported Commit Types

Type	Description
`feat`	A new feature
`fix`	A bug fix
`docs`	Documentation only changes
`style`	Changes that do not affect the meaning of the code (white-space, formatting, etc)
`refactor`	A code change that neither fixes a bug nor adds a feature
`test`	Adding missing tests or correcting existing tests
`chore`	Changes to the build process or auxiliary tools
`build`	Changes to the build system
`ci`	Changes to CI configuration
`perf`	A code change that improves performance
`revert`	Reverts a previous commit

Configuration

The tool supports custom configuration files. By default, it searches for:

.commitlintrc.js
.commitlintrc.json
.commitlintrc.yaml
.commitlintrc.yml
commitlint.config.js
.git-commit-prefix-gen.yaml
.git-commit-prefix-gen.json

Example Configuration

type_mapping:
  - pattern: "src/**/*.rs"
    type: "feat"
  - pattern: "tests/**/*.rs"
    type: "test"
  - pattern: "docs/**/*.md"
    type: "docs"

scope_patterns:
  - pattern: "^src/([^/]+)/"
    base: "src"
  - pattern: "^lib/([^/]+)/"
    base: "lib"

ignored_patterns:
  - "^target/"
  - "^node_modules/"
  - "^\\.git/"

Exit Codes

Code	Description
0	Success
1	No changes detected or error
128	Not in a git repository

Library Usage

use git_commit_prefix_gen::{Analyzer, CommitConvention};

fn main() {
    let convention = CommitConvention::default();
    let analyzer = Analyzer::with_convention(convention);

    let changes = analyzer.analyze(&std::env::current_dir().unwrap()).unwrap();
    let suggestions = analyzer.generate_suggestions(&changes);

    for suggestion in &suggestions {
        println!("{}", suggestion);
    }
}

Development

# Run tests
cargo test

# Run tests with verbose output
cargo test -- --nocapture

# Build
cargo build

# Build release
cargo build --release

# Run examples
cargo run --example basic_usage
cargo run --example custom_config

Dependencies

git2 - Git bindings
clap - CLI argument parsing
serde - Serialization
regex - Pattern matching
anyhow - Error handling
dialoguer - Interactive prompts