What is istanbul-reports?
The istanbul-reports npm package is used for generating coverage reports in various formats from Istanbul coverage JSON objects. Istanbul is a JavaScript code coverage tool that computes statement, line, function, and branch coverage with module loader hooks to work seamlessly with the code. The reports generated by istanbul-reports can be in HTML, text, text-summary, lcov, and more, which are useful for visualizing and understanding the code coverage of a project.
What are istanbul-reports's main functionalities?
HTML Report Generation
Generates a detailed HTML report that visualizes code coverage with syntax highlighting, directory views, and file views.
const reports = require('istanbul-reports');
const libReport = require('istanbul-lib-report');
// Assuming you have a coverageMap object
const context = libReport.createContext({
dir: 'coverage', // output directory
coverageMap: coverageMap
});
const report = reports.create('html', {
// any options here
});
report.execute(context);
Text Report Generation
Produces a simple text report that summarizes the coverage metrics, which can be output to the console or a file.
const reports = require('istanbul-reports');
const libReport = require('istanbul-lib-report');
// Assuming you have a coverageMap object
const context = libReport.createContext({
dir: 'coverage', // output directory
coverageMap: coverageMap
});
const report = reports.create('text');
report.execute(context);
LCOV Report Generation
Creates an lcov report that is compatible with tools that accept the lcov format, such as coveralls.io.
const reports = require('istanbul-reports');
const libReport = require('istanbul-lib-report');
// Assuming you have a coverageMap object
const context = libReport.createContext({
dir: 'coverage', // output directory
coverageMap: coverageMap
});
const report = reports.create('lcovonly');
report.execute(context);
Other packages similar to istanbul-reports
nyc
nyc is the official command-line interface for Istanbul and provides additional features like subprocess coverage and support for ES2015+. It wraps istanbul-lib-instrument, istanbul-lib-report, and istanbul-reports among others, to provide an all-in-one coverage solution.
c8
c8 is a high-performance code coverage tool for Node.js that uses V8's built-in code coverage rather than instrumenting the code like Istanbul. It is faster and has less overhead but may not support all the features and customizations that Istanbul provides.
coveralls
Coveralls is a web service that helps you track your code coverage over time, and ensure that all your new code is fully covered. It integrates with your CI environment and can work with Istanbul's lcov reports to provide detailed coverage statistics.
codecov
Codecov is another code coverage service similar to Coveralls. It can process reports generated by Istanbul and other coverage tools to provide insights into code coverage with features like pull request comments, coverage graphs, and more.