stryker

Stryker

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.

Work in progress

This repository is a work in progress. We only support Jasmine tests in the browser for now. Please create and vote on issues to help us determine the priority on features.

Getting started

Stryker is a mutation testing framework for JavaScript. It allows you to test your test by temporarily inserting bugs.

To install stryker, execute the command:

npm install stryker --save-dev

Note*: During the installation you may run into errors caused by node-gyp. It is safe to ignore these errors.*

To test if stryker is working, execute the command:

node node_modules/stryker/dist/src/Stryker.js --help

Configuration

Required options

Files to mutate

Short notation: -m
Full notation: --mutate
Optional: No
Description:
A comma seperated list of globbing expressions used for selecting the files that should be mutated.
Example: -m src/**/*.js,a.js`

All files

Short notation: -f
Full notation: --files
Optional: No
Description:
A comma seperated list of globbing expressions used for selecting all files needed to run the tests. These include: test files, library files, source files (the files selected with --mutate) and any other file you need to run your tests. The order of the files specified here will be the order used to load the file in the test runner, for example: karma.
Example: -f node_modules/a-lib/**/*.js,src/**/*.js,a.js,test/**/*.js

Default config

By default, stryker requires two arguments: the source and test files.
When calling stryker with multiple source and/or test files, they have to be separated using comma's.

A basic usage of stryker is:

node node_modules/stryker/src/Stryker.js –m src/myFirstFile.js,src/mySecondFile.js –f libs/externalLibrary.js,src/myFirstFile.js,src/mySecondFile.js,test/*.js,

Supported mutations

Math

Original	Mutated
a + b	a - b
a - b	a + b
a * b	a / b
a / b	a * b
a & b	a * b

Unary

Original	Mutated
a++	a--
a--	a++
++a	--a
--a	++a
+a	-a
-a	+a

Conditional boundary

Original	Mutated
a < b	a <= b
a <= b	a < b
a > b	a >= b
a >= b	a < b

Reverse conditional

Original	Mutated
a == b	a != b
a != b	a == b
a === b	a !== b
a !== b	a === b
a <= b	a > b
a >= b	a < b
a < b	a >= b
a > b	a <= b
a && b	a || b
a || b	a && b

Remove conditionals

Original	Mutated
for (var i = 0; i < 10; i++) { }	for (var i = 0; false; i++) { }
while (a > b) { }	while (false) { }
do { } while (a > b);	do { } while (false);
if (a > b) { }	if (true) { }
if (a > b) { }	if (false) { }