istanbul-lib-coverage
Advanced tools
Package description
The istanbul-lib-coverage package is a library for JavaScript test coverage measurement and reporting. It provides a set of APIs to instrument code, collect and aggregate coverage data, and generate reports in various formats. It's part of the Istanbul project, which is widely used for tracking code coverage in JavaScript applications.
Creating a Coverage Map
This feature allows you to create a new coverage map. A coverage map is a data structure that holds coverage data for a set of files. This is the first step in collecting and storing coverage information.
const libCoverage = require('istanbul-lib-coverage');
const map = libCoverage.createCoverageMap();Adding File Coverage
After creating a coverage map, you can add coverage data for individual files. This involves creating a file coverage object for each file and adding it to the coverage map. This is how you populate the coverage map with data.
const fileCoverage = libCoverage.createFileCoverage('path/to/file.js');
map.addFileCoverage(fileCoverage);Generating Summary Reports
Once you have a populated coverage map, you can generate summary reports. These summaries provide an overview of the coverage data, including statistics like lines covered, statements covered, and so forth. This is useful for getting a quick insight into the coverage of your project.
const summary = map.getCoverageSummary();
console.log(summary.toJSON());nyc is a command-line-interface tool that wraps istanbul-lib-coverage and other Istanbul libraries to provide a simplified user experience for instrumenting code, running tests, and generating coverage reports. It's more of a complete toolset compared to the lower-level API functionality provided by istanbul-lib-coverage.
c8 leverages the built-in V8 coverage tool to collect test coverage. Unlike istanbul-lib-coverage, which instruments the source code to track coverage, c8 works at the V8 engine level, providing potentially more accurate coverage metrics without the need to modify the source code. This difference in approach makes c8 a compelling alternative for projects that can benefit from native coverage collection.
Jest is a popular testing framework that includes built-in coverage reporting capabilities. While istanbul-lib-coverage is focused solely on coverage collection and reporting, Jest provides a comprehensive testing solution that includes assertions, mocks, and coverage. Jest uses Istanbul under the hood for coverage reporting, making it a higher-level alternative that integrates testing and coverage.
Readme
An API that provides a read-only view of coverage information with the ability to merge and summarize coverage info.
Supersedes object-utils and collector from the v0 istanbul API.
See the docs for the full API.
var libCoverage = require('istanbul-lib-coverage');
var map = libCoverage.createCoverageMap(globalCoverageVar);
var summary = libCoverage.createCoverageSummary();
// merge another coverage map into the one we created
map.merge(otherCoverageMap);
// inspect and summarize all file coverage objects in the map
map.files().forEach(function(f) {
var fc = map.fileCoverageFor(f),
s = fc.toSummary();
summary.merge(s);
});
console.log('Global summary', summary);
FAQs
Data library for istanbul coverage objects
The npm package istanbul-lib-coverage receives a total of 24,860,710 weekly downloads. As such, istanbul-lib-coverage popularity was classified as popular.
We found that istanbul-lib-coverage demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 4 open source maintainers collaborating on the project.
Did you know?
Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.
Security News
UnitedHealth Group disclosed that the ransomware attack on Change Healthcare compromised protected health information for millions in the U.S., with estimated costs to the company expected to reach $1 billion.
Security News
GitHub is susceptible to a CDN flaw that allows attackers to host malware on any public repository.
Security News
At Node Congress, Socket CEO Feross Aboukhadijeh uncovers the darker aspects of open source, where applications that rely heavily on third-party dependencies can be exploited in supply chain attacks.