What is babel-plugin-istanbul?
The babel-plugin-istanbul npm package is used to instrument your JavaScript code with Istanbul coverage. It works seamlessly with Babel and test runners like Mocha, Jest, and others to generate coverage reports. This plugin is typically used during testing to collect information about which parts of your codebase are covered by tests.
What are babel-plugin-istanbul's main functionalities?
Code Instrumentation
This feature automatically instruments your code with Istanbul coverage when it is being transpiled by Babel. The code sample shows how to apply the plugin when transforming code with Babel.
require('babel-core').transform('code', { plugins: ['istanbul'] });
Coverage Reporting
After running tests with the instrumented code, you can generate coverage reports in various formats using Istanbul's command line tool, nyc. The code sample shows how to generate a text report.
nyc report --reporter=text
Configuration Options
The plugin allows you to specify options such as excluding files or directories from being instrumented. The code sample demonstrates how to exclude all files in the 'test' directory.
{ 'plugins': [['istanbul', { 'exclude': ['test/**/*.js'] }]] }
Other packages similar to babel-plugin-istanbul
nyc
nyc is Istanbul's command line interface and can be used for instrumenting code, running tests, and generating coverage reports. It works well with subprocesses and can be used as a standalone tool without Babel.
istanbul
istanbul is the original code coverage tool that provides a JavaScript API for instrumenting code, as well as a command line tool for generating reports. It is the underlying tool that babel-plugin-istanbul and nyc are built upon.
jest
Jest is a testing framework that includes its own coverage reporting capabilities. It uses Istanbul under the hood for coverage instrumentation and can generate coverage reports without the need for additional plugins.
karma-coverage
karma-coverage is a plugin for the Karma test runner that generates code coverage reports using Istanbul. It is similar to babel-plugin-istanbul but is specifically designed to work within the Karma ecosystem.