Jest support for Jenkins JS Builder

Run your tests with Jenkins JS Builder using the "Jest" test runner.

Setup

1. Add a gulpfile with the following line:

   const jsb = require('@jenkins-cd/js-builder');

2. Install the @jenkins-cd/js-builder-jest dependency.

3. Setup npm scripts

   It is convenient to invoke js-builder-jest via npm scripts. Add the following to the "scripts" block in package.json:

   "test": "gulp test",
   "test:fast": "gulp test:fast",
   "test:debug": "node --debug-brk ./node_modules/.bin/gulp test:debug",

Defaults

The default location for tests is the test folder. This can be overridden by calling builder.tests(<new-path> in the gulpfile.

The file names need to match the pattern *-spec.js or *-test.js; the jsx extension is also supported.

'test' Task

Run the tests and produces test and coverage reports.

You can limit the tests that are run via the test parameter. This is a pattern that is passed to Jest's testPathPattern CLI parameter.

JUnit test reports are stored in target/jest-reports/ and coverage reports in target/jest-coverage/. Note that coverage is only measured for .js and .jsx files in the source directories (default: src).

'test:fast" Task

npm run test:fast

Runs the tests but skips generation of reports and coverage. This is good for local development.

'test:debug' Task

npm run test:debug

Runs the tests in debug mode on default port 5858. Test execution will be paused until the debugger is attached and execution is resumed.

Running specific tests

Run a single test.

npm run test -- --test test/src/js/foo/bar/foobar-spec

Runs any test with 'calculator' in the path or name.

npm run test -- --test calculator

Run any test inside of a 'math' folder.

npm run test -- --test /math/

Using custom configuration

Jest configuration

Jest's command line runner supports custom configuration placed in a "jest" property in package.json. js-builder-jest will automatically add these configuration options if they are defined.

Jest CLI Options

Jest also supports useful CLI options. These can be used in two ways:

In npm scripts

"test:fast": "gulp test:fast --updateSnapshot",

From command line

npm run test:fast -- --updateSnapshot

Note the double dash above.