gulp-istanbul

Istanbul unit test coverage plugin for gulp.

Works on top of any Node.js unit test framework.

Installation

npm install --save-dev gulp-istanbul

Example

In your gulpfile.js:

Node.js testing

var istanbul = require('gulp-istanbul');
// We'll use mocha in this example, but any test framework will work
var mocha = require('gulp-mocha');

gulp.task('pre-test', function () {
  return gulp.src(['lib/**/*.js'])
    // Covering files
    .pipe(istanbul())
    // Force `require` to return covered files
    .pipe(istanbul.hookRequire());
});

gulp.task('test', ['pre-test'], function () {
  return gulp.src(['test/*.js'])
    .pipe(mocha())
    // Creating the reports after tests ran
    .pipe(istanbul.writeReports())
    // Enforce a coverage of at least 90%
    .pipe(istanbul.enforceThresholds({ thresholds: { global: 90 } }));
});

Note: Version 4.x.x of gulp-mocha is not supported (see issue #115 for details). In this example, you should use gulp-mocha version 3.0.1 for the time being.

Browser testing

For browser testing, you'll need to write the files covered by istanbul in a directory from where you'll serve these files to the browser running the test. You'll also need a way to extract the value of the coverage variable after the test have runned in the browser.

Browser testing is hard. If you're not sure what to do, then I suggest you take a look at Karma test runner - it has built-in coverage using Istanbul.

var istanbul = require('gulp-istanbul');


gulp.task('pre-test', function () {
  return gulp.src(['lib/**/*.js'])
    // Covering files
    .pipe(istanbul())
    // Write the covered files to a temporary directory
    .pipe(gulp.dest('test-tmp/'));
});

gulp.task('test', ['pre-test'], function () {
  // Make sure your tests files are requiring files from the
  // test-tmp/ directory
  return gulp.src(['test/*.js'])
    .pipe(testFramework())
    // Creating the reports after tests ran
    .pipe(istanbul.writeReports());
});

Source Maps

gulp-istanbul supports gulp-sourcemaps when instrumenting:

gulp.task('pre-test', function () {
  return gulp.src(['lib/**/*.js'])
    // optionally load existing source maps
    .pipe(sourcemaps.init())
    // Covering files
    .pipe(istanbul())
    .pipe(sourcemaps.write('.'))
    // Write the covered files to a temporary directory
    .pipe(gulp.dest('test-tmp/'));
});

API

istanbul(opt)

Instrument files passed in the stream.

opt

Type: Object (optional)

{
  coverageVariable: 'someVariable',
  ...other Instrumeter options...
}

coverageVariable

Type: String (optional) Default: '$$cov_' + new Date().getTime() + '$$'

The global variable istanbul uses to store coverage

See also:

• istanbul coverageVariable
• SanboxedModule

includeUntested

Type: Boolean (optional) Default: false

Flag to include test coverage of files that aren't required by any tests

See also:

• istanbul "0% coverage" issue

instrumenter

Type: Instrumenter (optional) Default: istanbul.Instrumenter

Custom Instrumenter to be used instead of the default istanbul one.

var isparta = require('isparta');
var istanbul = require('gulp-istanbul');

gulp.src('lib/**.js')
  .pipe(istanbul({
    // supports es6
    instrumenter: isparta.Instrumenter
  }));

See also:

• isparta

Other Istanbul Instrumenter options

See:

• istanbul Instrumenter documentation

istanbul.hookRequire()

Overwrite require so it returns the covered files. The method take an optional option object.

Always use this option if you're running tests in Node.js

istanbul.summarizeCoverage(opt)

get coverage summary details

opt

Type: Object (optional)

{
  coverageVariable: 'someVariable'
}

coverageVariable

Type: String (optional) Default: '$$cov_' + new Date().getTime() + '$$'

The global variable istanbul uses to store coverage

See also:

• istanbul coverageVariable
• SanboxedModule

returns

Type: Object

{
  lines: { total: 4, covered: 2, skipped: 0, pct: 50 },
  statements: { total: 4, covered: 2, skipped: 0, pct: 50 },
  functions: { total: 2, covered: 0, skipped: 0, pct: 0 },
  branches: { total: 0, covered: 0, skipped: 0, pct: 100 }
}

See also:

• istanbul utils.summarizeCoverage()

istanbul.writeReports(opt)

Create the reports on stream end.

opt

Type: Object (optional)

{
  dir: './coverage',
  reporters: [ 'lcov', 'json', 'text', 'text-summary', CustomReport ],
  reportOpts: { dir: './coverage' },
  coverageVariable: 'someVariable'
}

You can pass individual configuration to a reporter.

{
  dir: './coverage',
  reporters: [ 'lcovonly', 'json', 'text', 'text-summary', CustomReport ],
  reportOpts: {
    lcov: {dir: 'lcovonly', file: 'lcov.info'}
    json: {dir: 'json', file: 'converage.json'}
  },
  coverageVariable: 'someVariable'
}

dir

Type: String (optional) Default: ./coverage

The folder in which the reports are to be outputted.

reporters

Type: Array (optional) Default: [ 'lcov', 'json', 'text', 'text-summary' ]

The list of available reporters:

• clover
• cobertura
• html
• json
• lcov
• lcovonly
• none
• teamcity
• text
• text-summary

You can also specify one or more custom reporter objects as items in the array. These will be automatically registered with istanbul.

See also require('istanbul').Report.getReportList()

reportOpts

Type: Object (optional)

{
  dir: './coverage'
}

You can also configure separate directory for each report.

{
  html: {
        dir: './coverage/html',
        watermarks: {
            statements: [ 50, 80 ],
            lines: [ 50, 80 ],
            functions: [ 50, 80],
            branches: [ 50, 80 ]
        }
    },
    lcov: {dir: './coverage/lcov'},
    lcovonly: {dir: './coverage/lcovonly'},
    json: {dir: './coverage/json'},
}

watermarks can be used to confgure the color of the HTML report. Default colors are.. RED: below 50% coverage, YELLOW: 50-80% coverage, GREEN: above 80%

coverageVariable

Type: String (optional) Default: '$$cov_' + new Date().getTime() + '$$'

The global variable istanbul uses to store coverage

See also:

• istanbul coverageVariable
• SanboxedModule

istanbul.enforceThresholds(opt)

Checks coverage against minimum acceptable thresholds. Fails the build if any of the thresholds are not met.

opt

Type: Object (optional)

{
  coverageVariable: 'someVariable',
  thresholds: {
    global: 60,
    each: -10
  }
}

coverageVariable

Type: String (optional) Default: '$$cov_' + new Date().getTime() + '$$'

The global variable istanbul uses to store coverage

thresholds

Type: Object (required)

Minimum acceptable coverage thresholds. Any coverage values lower than the specified threshold will fail the build.

Each threshold value can be:

• A positive number - used as a percentage
• A negative number - used as the maximum amount of coverage gaps
• A falsey value will skip the coverage

Thresholds can be specified across all files (global) or per file (each):

{
  global: 80,
  each: 60
}

You can also specify a value for each metric:

{
  global: {
    statements: 80,
    branches: 90,
    lines: 70,
    functions: -10
  }
  each: {
    statements: 100,
    branches: 70,
    lines: -20
  }
}

emits

A plugin error in the stream if the coverage fails

License

MIT License (c) Simon Boudrias - 2013