mo3ta-coverage

mo3ta-coverage checks coverage for changed lines in a pull request. It finds changed source files, maps them to likely test files, runs Jest in a selected execution mode, and validates changed-line coverage against a threshold.

Features

• Detects changed JS/TS files from git history and working tree
• Maps changed source files to nearby test files automatically
• Supports three execution modes: fast, smart, and full
• Parses lcov.info and reports uncovered changed lines
• Enforces a minimum coverage threshold for changed lines

Installation

npm install -g mo3ta-coverage

Usage

mo3ta-coverage --mode smart --base origin/main --limit 80

CLI Options

| Option | Description | Default | |--------|-------------|---------| | --base <branch> | Base branch to compare against | origin/main | | --lcov <path> | Path to lcov.info | coverage/lcov.info | | --limit <percent> | Minimum changed-line coverage percentage | 80 | | --showCovered <bool> | Show covered changed lines in output | false | | --mode <mode> | Execution mode: fast, smart, or full | smart |

Modes

• fast: Direct execution of mapped test files only. No Jest dependency traversal.
• smart: Direct execution of changed source files plus mapped test files. No Jest dependency traversal.
• full: Runs mapped test files through jest --findRelatedTests.

Recommended Mode

For most projects, especially large ones with shared helpers or deep import graphs, use:

mo3ta-coverage --mode smart --base origin/main --limit 80

Use full only when you intentionally want Jest to expand to related tests.

Configuration

You can persist defaults with the config subcommand:

mo3ta-coverage config --base origin/main --mode smart

This writes .mo3ta-coverage.json in the project root.

How It Works

1. Reads CLI options and saved config from index.js.
2. Finds changed source files from git in src/cli.js.
3. Maps source files to nearby test files in src/fileUtils.js.
4. Runs Jest in the selected mode from src/cli.js.
5. Parses lcov.info and reports uncovered changed lines.

Development

npm install
npm test

License

MIT