eslint-mocha-no-only

This package contains an ESLint rule which throws an error (or warning) when the only() method is called on describe, context, it, specify, suite and test Mocha test keywords.

Why do I need this?

only() is a useful Mocha feature that lets the test runner run one specific part of a test suite. Often, developers may end up forgetting to remove the only() method before commiting and pushing their code. This results in the CI tool running only one specific test in the suite which may end up in a false-positive build.

By having ESLint throw an error in such cases, you can rest assured your CI tool runs all your test suites.

Installation

You'll first need to install ESLint:

$ npm i eslint --save-dev

Next, install eslint-plugin-mocha-no-only:

$ npm install eslint-plugin-mocha-no-only --save-dev

Note: If you installed ESLint globally (using the -g flag) then you must also install eslint-plugin-mocha-no-only globally.

Usage

Add eslint-plugin-mocha-no-only to the plugins section of your .eslintrc configuration file. You can omit the eslint-plugin- prefix:

 {
    "plugins": [
        "mocha-no-only"
    ]
}

Then configure the rules you want to use under the rules section.

 {
    "rules": {
        "mocha-no-only/mocha-no-only": ["error"]
    }
}

Note: You may want to have a different .eslintrc file in your tests directory and place this plugin and rule in it. This would make sure ESLint doesn't throw errors on other JavaScript object named describe.only(), for example. There's also no need to have ESLint watch for this rule in files where there are no mocha tests.

Examples

Failing

  describe("foobar", function() {
    var foo;
    beforeEach(function() {
      foo = new Foo();
    });

    it.only("should do things", function() {
      expect(foo).to.do.things;
    });
  });

Passing

  describe("foobar", function() {
    var foo;
    beforeEach(function() {
      foo = new Foo();
    });

    it("should do things", function() {
      expect(foo).to.do.things;
    });
  });