coveralls

What is coveralls?

The coveralls npm package is used to integrate your project with Coveralls, a web service that provides test coverage history and statistics. It helps developers ensure that their code is well-tested by tracking the percentage of code covered by tests over time.

What are coveralls's main functionalities?

Sending Coverage Reports

This feature allows you to send your test coverage reports to Coveralls. The code sample reads the coverage report from a file and sends it to Coveralls using the `handleInput` method.

const coveralls = require('coveralls');
const fs = require('fs');

fs.readFile('coverage/lcov.info', 'utf8', (err, data) => {
  if (err) {
    console.error('Error reading coverage file:', err);
    return;
  }
  coveralls.handleInput(data, (err) => {
    if (err) {
      console.error('Error sending to Coveralls:', err);
    } else {
      console.log('Coverage report sent to Coveralls');
    }
  });
});

Custom Git Information

This feature allows you to send custom Git information along with your coverage report. The code sample demonstrates how to include custom Git metadata when sending the coverage report to Coveralls.

const coveralls = require('coveralls');
const fs = require('fs');

const gitInfo = {
  head: {
    id: 'commit-sha',
    author_name: 'Author Name',
    author_email: '[e-mail]',
    committer_name: 'Committer Name',
    committer_email: '[e-mail]',
    message: 'Commit message'
  },
  branch: 'main'
};

fs.readFile('coverage/lcov.info', 'utf8', (err, data) => {
  if (err) {
    console.error('Error reading coverage file:', err);
    return;
  }
  coveralls.handleInput(data, { git: gitInfo }, (err) => {
    if (err) {
      console.error('Error sending to Coveralls:', err);
    } else {
      console.log('Coverage report with custom git info sent to Coveralls');
    }
  });
});

Other packages similar to coveralls

codecov

Codecov is another popular service for tracking code coverage. It provides similar functionalities to Coveralls, such as integrating with CI/CD pipelines and supporting multiple languages and coverage formats. Codecov also offers additional features like detailed coverage graphs and pull request comments.

nyc

NYC is a command-line tool for generating code coverage reports. It is often used in conjunction with other tools like Mocha or Jest. While NYC itself does not provide a web service for tracking coverage history, it can be used to generate coverage reports that can then be sent to services like Coveralls or Codecov.

jest

Jest is a JavaScript testing framework that includes built-in support for generating code coverage reports. While Jest focuses more on testing, it can be configured to output coverage reports in formats compatible with services like Coveralls and Codecov.

README

node-coveralls

Coveralls.io support for node.js. Get the great coverage reporting of coveralls.io and add a cool coverage button ( like the one above ) to your README.

Supported CI services: travis-ci, codeship, circleci, jenkins, Gitlab CI

Installation:

Add the latest version of coveralls to your package.json:

npm install coveralls --save-dev

If you're using mocha, add mocha-lcov-reporter to your package.json:

npm install mocha-lcov-reporter --save-dev

Usage:

This script ( bin/coveralls.js ) can take standard input from any tool that emits the lcov data format (including mocha's LCov reporter) and send it to coveralls.io to report your code coverage there.

Once your app is instrumented for coverage, and building, you need to pipe the lcov output to ./node_modules/coveralls/bin/coveralls.js.

This library currently supports travis-ci with no extra effort beyond piping the lcov output to coveralls. However, if you're using a different build system, there are a few environment variables that are necessary:

• COVERALLS_SERVICE_NAME (the name of your build system)
• COVERALLS_REPO_TOKEN (the secret repo token from coveralls.io)

There are optional environment variables for other build systems as well:

• COVERALLS_SERVICE_JOB_ID (an id that uniquely identifies the build job)
• COVERALLS_RUN_AT (a date string for the time that the job ran. RFC 3339 dates work. This defaults to your build system's date/time if you don't set it.)
• COVERALLS_PARALLEL (more info here: https://coveralls.zendesk.com/hc/en-us/articles/203484329)

Mocha + Blanket.js

• Install blanket.js
• Configure blanket according to docs.
• Run your tests with a command like this:

NODE_ENV=test YOURPACKAGE_COVERAGE=1 ./node_modules/.bin/mocha \
  --require blanket \
  --reporter mocha-lcov-reporter | ./node_modules/coveralls/bin/coveralls.js

Mocha + JSCoverage

Instrumenting your app for coverage is probably harder than it needs to be (read here), but that's also a necessary step.

In mocha, if you've got your code instrumented for coverage, the command for a travis build would look something like this:

YOURPACKAGE_COVERAGE=1 ./node_modules/.bin/mocha test -R mocha-lcov-reporter | ./node_modules/coveralls/bin/coveralls.js

Check out an example Makefile from one of my projects for an example, especially the test-coveralls build target. Note: Travis runs npm test, so whatever target you create in your Makefile must be the target that npm test runs (This is set in package.json's 'scripts' property).

Istanbul

With Mocha:

istanbul cover ./node_modules/mocha/bin/_mocha --report lcovonly -- -R spec && cat ./coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js && rm -rf ./coverage

With Jasmine:

istanbul cover jasmine-node --captureExceptions spec/ && cat ./coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js && rm -rf ./coverage

Nodeunit + JSCoverage

Depend on nodeunit, jscoverage and coveralls:

npm install nodeunit jscoverage coveralls --save-dev

Add a coveralls script to "scripts" in your package.json:

"scripts": {
  "test": "nodeunit test",
  "coveralls": "jscoverage lib && YOURPACKAGE_COVERAGE=1 nodeunit --reporter=lcov test | coveralls"
}

Ensure your app requires instrumented code when process.env.YOURPACKAGE_COVERAGE variable is defined.

Run your tests with a command like this:

npm run coveralls

For detailed instructions on requiring instrumented code, running on Travis and submitting to coveralls see this guide.

Poncho

Client-side JS code coverage using PhantomJS, Mocha and Blanket:

• Configure Mocha for browser
• Mark target script(s) with data-cover html-attribute
• Run your tests with a command like this:

./node_modules/.bin/poncho -R lcov test/test.html | ./node_modules/coveralls/bin/coveralls.js

Lab

lab -r lcov | ./node_modules/.bin/coveralls

nyc

works with almost any testing framework. Simply execute npm test with the nyc bin followed by running its reporter:

nyc npm test && nyc report --reporter=text-lcov | coveralls

TAP

Simply run your tap tests with the COVERALLS_REPO_TOKEN environment variable set and tap will automatically use nyc to report coverage to coveralls.

Command Line Parameters

Usage: coveralls.js [-v] filepath

Optional arguments:

-v, --verbose

filepath - optionally defines the base filepath of your source files.

Running locally

If you're running locally, you must have a .coveralls.yml file, as documented in their documentation, with your repo_token in it; or, you must provide a COVERALLS_REPO_TOKEN environment-variable on the command-line.

If you want to send commit data to coveralls, you can set the COVERALLS_GIT_COMMIT environment-variable to the commit hash you wish to reference. If you don't want to use a hash, you can set it to HEAD to supply coveralls with the latest commit data. This requires git to be installed and executable on the current PATH.

Contributing

I generally don't accept pull requests that are untested, or break the build, because I'd like to keep the quality high (this is a coverage tool afterall!).

I also don't care for "soft-versioning" or "optimistic versioning" (dependencies that have ^, x, > in them, or anything other than numbers and dots). There have been too many problems with bad semantic versioning in dependencies, and I'd rather have a solid library than a bleeding edge one.