Mutode NPM | npm.io

Mutode

Mutation testing for Node.js and JavaScript.

Mutode generates mutants (small changes of code) and runs your tests. If the tests fail, it means the mutant was detected and killed; if your tests pass, it means the mutant survived and your tests can be improved.

Read the thesis proposal here

Watch the demo video

"It's like a test for your tests!" - @mappum
"Higher order testing: automated testing for your unit tests" - @albertomiranda

Requires Node 8+

Install

Globally:

npm i -g mutode

Locally as a dev dependency:

npm i -D mutode

Use

Globally:

mutode [options] [paths]

Locally with npx:

npx mutode [options] [paths]

Locally with a package.json script:

{
  ...
  "scripts": {
    "test: "my test command",
    "mutode": "mutode [options] [paths]"
  }
  ...
}

Options:

Usage: mutode [options] [paths]

Options:
  --concurrency, -c  Concurrency of mutant runners         [number] [default: 4]
  --mutators, -m     Specific mutators to load (space separated)
      [array] [choices: "booleanLiterals", "conditionalsBoundary", "increments",
             "invertNegatives", "math", "negateConditionals", "numericLiterals",
              "removeArrayElements", "removeConditionals", "removeFuncCallArgs",
         "removeFuncParams", "removeFunctions", "removeLines", "removeObjProps",
                                          "removeSwitchCases", "stringLiterals"]
  -h, --help         Show help                                         [boolean]
  -v, --version      Show version number                               [boolean]