danger-plugin-coverage

npm version semantic-release .github/workflows/deploy.yml

A Danger plugin to report code coverage.

This plugin detects and parses coverage reports, posting the results as a Markdown table back to the pull request.

It uses the clover.xml format, which is output by Istanbul, a coverage reporter integrated with JavaScript testing tools such as Jest and Karma.

This format can also be output by testing libraries for other languages, such as PHPUnit. So, while this is primarily intended as a tool to run against JavaScript packages it would technically work as a coverage reporter for other languages too.

View an example report

Coverage Report

Test coverage is looking a little low for the files created or modified in this PR, perhaps we need to improve this.

Coverage threshold for branches (80%) not met: 49.08%
Coverage threshold for functions (80%) not met: 74.46%
Impacted Files % Stmts % Branch % Funcs % Line Uncovered Lines
src/module-one.js 100 100 100 100 :white_check_mark:
src/module-two.js 95.24 33.33 66.67 80 1, 42, 1337... :x:
src/module-three.js 82.33 10.25 44.55 45.55 12, 15, 32... :x:
src/module-four.js 100 0 10 32.5 54, 65, 94... :x:
src/module-five.js 100 100 100 100 :white_check_mark:

and 2 more...

Impacted Files % Stmts % Branch % Funcs % Line Uncovered Lines
src/module-six.js 100 100 100 100 :white_check_mark:
src/module-seven.js 100 100 100 100 :white_check_mark:

Usage

Install:

yarn add danger-plugin-coverage --dev

At a glance:

// dangerfile.js
import coverage from 'danger-plugin-coverage';

schedule(coverage());

Note that the coverage report output by your test runner must exist before Danger is run. By default we will look for the report at coverage/clover.xml, which is the default output location for Jest.

Settings

The function accepts a settings object with the following properties:

name description
successMessage A custom message to show when coverage is above the threshold.
failureMessage A custom message to show when coverage is below the threshold.
cloverReportPath Override automatic coverage report detection to provide the relative path to a report.
maxRows The number of rows to show (additional rows will be collapsed within a <details> element).
maxChars The maximum number of characters to allow in a file name cell.
maxUncovered The maximum number of uncovered lines to show.
wrapFilenames Wrap long file names to help the table fit in a PR comment.
threshold The thresholds at which to show the failure messaging.
warnOnNoReport Show a warning if no coverage report was detected.

Example (defaults shown):

import coverage from 'danger-plugin-coverage';

schedule(coverage({
  successMessage: ':+1: Test coverage is looking good.',
  failureMessage: 'Test coverage is looking a little low for the files created '
    + 'or modified in this PR, perhaps we need to improve this.',
  cloverReportPath: './coverage/clover.xml',
  maxRows: 3,
  maxChars: 100,
  maxUncovered: 10,
  wrapFilenames: true,
  warnOnNoReport: true,
  showAllFiles: false,
  threshold: {
    statements: 80,
    branches: 80,
    functions: 80,
    lines: 80,
  },
}));