danger-plugin-coverage-plus

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		✅
src/module-two.js	95.24	33.33	66.67	80	1, 42, 1337...	❌
src/module-three.js	82.33	10.25	44.55	45.55	12, 15, 32...	❌
src/module-four.js	100	0	10	32.5	54, 65, 94...	❌
src/module-five.js	100	100	100	100		✅

and 2 more...

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

Usage

Install:

yarn add danger-plugin-coverage-plus --dev

At a glance:

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

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
title	Custom title for the coverage report (defaults to "Coverage Report").
note	Optional note to display below the title.
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.
onFailure	Custom handler for failures.
altFileUrl	Base URL path to use for file links instead of GitHub blob links.
altFileUrlSuffix	Suffix to append to file paths when generating links.
replaceFilePrefix	Prefix to remove from file paths when generating links.

Example (defaults shown):

import coverage from 'danger-plugin-coverage-plus';

schedule(coverage({
  title: "Custom Coverage Report",
  note: "View content by clicking on file names"
  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,
  },
  onFailure: function log() { markdown("Failure") },
  altFileUrl: 'https://coverage.example.com', // Coverage report is hosted here
  altFileUrlSuffix: ".html",
  replaceFilePrefix: 'src/js', // Remove this prefix from file paths when generating coverage report links
}));