coverage

coverage

A command-line tool to collect and report code coverage of a JavaScript program

$ coverage test.js

✔ write a file
✔ create directories as needed
✔ validate arguments

3 of 3 passed.

----------|----------|----------|----------|----------|-------------------|
File      |  % Stmts | % Branch |  % Funcs |  % Lines | Uncovered Line #s |
----------|----------|----------|----------|----------|-------------------|
All files |    95.15 |    79.52 |      100 |    95.09 |                   |
 index.js |     90.6 |    75.38 |      100 |    90.52 |... 44,148,152,156 |
 lib.js   |      100 |    94.44 |      100 |      100 |               107 |
----------|----------|----------|----------|----------|-------------------|

This is an opinionated wrapper of c8, different in the following points:

• Runs both html and text reporter by default
• Automatically enables ECMAScript module support for .mjs files
• The first argument can be a JavaScript file path instead of a command
• Built-in Codecov support

Installation

Use npm.

npm install coverage

Once this package is installed to the project directory, users can execute coverage command inside npm scripts.

CLI

coverage [options] <file|command> [args]

Execute the command, print code coverage to the stdout and write HTML reports under the ./coverage directory.

<file|command> can be either a JavaScript file path or a command. If a path is provided, the file is run with the node command.

$ coverage /path/to/entry-point.js # is the same as ↓
$ coverage node /path/to/entry-point.js

If the provided JavaScript path ends with .mjs,

• ECMAScript module mode is automatically enabled.
• --es-module-specifier-resolution is automatically set to node.
• Experimental JSON modules support is automatically enabled.

Reporters

Users can override the default format of reports with --reporter option.

$ coverage example.js
------------|----------|----------|----------|----------|-------------------|
File        |  % Stmts | % Branch |  % Funcs |  % Lines | Uncovered Line #s |
------------|----------|----------|----------|----------|-------------------|
All files   |      100 |      100 |      100 |      100 |                   |
 example.js |      100 |      100 |      100 |      100 |                   |
------------|----------|----------|----------|----------|-------------------|

$ coverage --reporter=text-summary example.js

=============================== Coverage summary ===============================
Statements   : 100% ( 1/1 )
Branches     : 100% ( 1/1 )
Functions    : 100% ( 0/0 )
Lines        : 100% ( 1/1 )
================================================================================

$ coverage --reporter=none example.js # No reports

Codecov integration

When the execution exits with code 0 on a CI service or GitHub Actions, it automatically uploads the generated coverage to Codecov. Whether CODECOV_TOKEN environment variable is required or not varies between services.

$ coverage test.js

[... test results and coverage ...]

==> Travis CI detected.
==> Reading reports
    + /home/travis/build/shinnn/coverage/coverage/lcov.info bytes=1399
==> Gzipping contents
==> Uploading reports
    -> Uploading
    -> View reports at https://codecov.io/github/shinnn/coverage/commit/e4f5880b8ec5885e6a0b79030df5871e19d6de1d

c8 command-line options are supported. Run npx coverage --help to show the detailed reference for them.

coverage report

Output a report in the format specified in --reporter option.

This subcommand is only available after coverage has already been run.

License

ISC License © 2019 Shinnosuke Watanabe