!StrykerJS

StrykerJS

Professor X: For someone who hates mutants... you certainly keep some strange company.
William Stryker: Oh, they serve their purpose... as long as they can be controlled.

Introduction

For an introduction to mutation testing and StrykerJS features, see stryker-mutator.io.

Getting started

Please follow the quickstart on the website.

For small js projects, you can try the following command:

``
npm install --save-dev @stryker-mutator/core


Only for small projects:


npx stryker run
`

It will run stryker with default values:

* Uses npm test as your test command
* Searches for files to mutate in the lib and src directories

Usage

`sh
$ npx stryker [options] [configFile]
`

See usage on stryker-mutator.io

Supported mutators

See our website for the list of currently supported mutators.

Configuration

See configuration on stryker-mutator.io.

Programmatic use

Stryker can also be used programmatically from nodejs. It exports 2 classes for you to use: Stryker and StrykerCli.

`ts
import { Stryker, StrykerCli } from '@stryker-mutator/core';
`

Both classes can be used to run Stryker. The main difference is that Stryker is a slightly more low-level approach, while StrykerCli is the straight up CLI api.

In this example you can see how to use both.

`ts
async function main() {
// Runs Stryker as if it was called directly from the cli. Not even returns a promise, it assumes to be allowed to call process.exit.
new StrykerCli(process.argv / RAW argv array / ).run();

// Runs Stryker, will not assume to be allowed to exit the process.
const stryker = new Stryker({ concurrency: 4 } / Partial Stryker options object / );
const mutantResults = await stryker.runMutationTest();
// mutantResults or rejected with an error.
}
``

Stryker is written in TypeScript, so it is recommended to use Typescript as well to get the best developer experience.