istanbul-api

What is istanbul-api?

The 'istanbul-api' npm package provides a set of APIs for working with code coverage in JavaScript projects. It is part of the Istanbul toolset, which is widely used for measuring code coverage in JavaScript applications. The package allows you to create coverage reports, manage coverage data, and instrument code for coverage analysis.

What are istanbul-api's main functionalities?

Creating Coverage Reports

This feature allows you to create coverage reports in various formats such as HTML. The code sample demonstrates how to create an HTML coverage report using the 'istanbul-api' package.

const istanbul = require('istanbul-api');
const reports = istanbul.reports;
const collector = new istanbul.Collector();
const reporter = reports.create('html', { dir: './coverage' });

collector.add(global.__coverage__);
reporter.writeReport(collector, true);

Managing Coverage Data

This feature allows you to manage and manipulate coverage data. The code sample shows how to create a coverage map and add file coverage data to it.

const istanbul = require('istanbul-api');
const coverageMap = istanbul.libCoverage.createCoverageMap();

coverageMap.addFileCoverage(global.__coverage__);
console.log(coverageMap.toJSON());

Instrumenting Code for Coverage

This feature allows you to instrument code for coverage analysis. The code sample demonstrates how to read a JavaScript file, instrument it for coverage, and write the instrumented code to a new file.

const istanbul = require('istanbul-api');
const instrumenter = istanbul.libInstrument.createInstrumenter();
const fs = require('fs');

const code = fs.readFileSync('path/to/your/file.js', 'utf8');
const instrumentedCode = instrumenter.instrumentSync(code, 'path/to/your/file.js');

fs.writeFileSync('path/to/your/instrumented-file.js', instrumentedCode);

Other packages similar to istanbul-api

nyc

NYC is a command-line interface for Istanbul. It provides a simple way to instrument and report code coverage for your JavaScript applications. NYC is often used in conjunction with testing frameworks like Mocha or Jest. Compared to 'istanbul-api', NYC is more user-friendly and easier to integrate into existing projects.

c8

C8 is a code coverage tool built on top of V8's built-in code coverage capabilities. It provides a fast and accurate way to measure code coverage for Node.js applications. C8 is particularly useful for projects that require high performance and accuracy. Unlike 'istanbul-api', C8 leverages V8's native coverage features, making it faster and more efficient.

jest

Jest is a JavaScript testing framework that comes with built-in code coverage support. It uses Istanbul under the hood to generate coverage reports. Jest provides an all-in-one solution for testing and coverage, making it a popular choice for many JavaScript projects. While 'istanbul-api' focuses solely on coverage, Jest offers a comprehensive testing and coverage solution.

README

istanbul-api

Deprecated high-level API for istanbul.

Remaining users of this module should migrate:

• istanbul-lib-instrument or babel-plugin-istanbul - modify sources to include coverage counters
• istanbul-lib-coverage - merge coverage results from multiple tests into a single dataset for reporting
• istanbul-lib-source-maps - process source-maps before generating reports
• istanbul-lib-report - the reporting system
• istanbul-reports - the actual reports (text-summary report, html report, etc)