gulp-spawn-mocha

This is a plugin for gulp which runs Mocha tests in a separate process from the gulp process. Each time tests are run a new child process is created meaning the test environment always starts cleanly (i.e., globals are reset as are non- enumerable properties defined on native prototypes via Object.defineProperty. This also means that if your tests crash the node process (e.g., process.exit(-1).) then an error event is emitted rather than your whole gulp process crashing (good for watching). It is simple enough to make gulp crash when necessary (e.g., for continuous integration) by throwing the error as outlined below.

Usage

Usage is according to this API:

stream.pipe(mocha({
  // options
}))

This plugin defines mocha ~1 as a peerDependency meaning that you can define a dependency on any version of mocha in your package.json and that version will be used to run tests. If you don't specify a mocha in your package.json, then the latest 1.x version will automatically be installed.

There are two special options: bin and env. You can set bin to be a path to a mocha executable to use instead of the one this plugin looks for by default. This is useful if you want to use a fork of mocha which goes by a different name. You can pass an object as the env option to set the environment variables that the child process will have access to (key-value pairs, see child_process::spawn).

All other options are properly prefixed with either - or -- and passed to the mocha executable. Any arguments which do not take a value (e.g., c, colors, or debug) should just have a value of true. See the following example usage:

var gulp = require('gulp'),
    mocha = require('gulp-spawn-mocha');

gulp.task('test', function () {
  return test().on('error', function (e) {
    throw e;
  });
});

gulp.task('default', function () {
  gulp.watch('{lib,test}/*', test);
  test();
});

function test() {
  return gulp.src(['test/*.test.js'], {read: false}).pipe(mocha({
    r: 'test/setup.js',
    R: 'spec',
    c: true,
    debug: true
  })).on('error', console.warn.bind(console));
}

The test function will run the mocha executable telling it to require test/setup.js and use the spec reporter -- if there is an error it will output a warning to the console. See mocha -h for additional options.

The test task will throw an error, crashing gulp (good for continuous integration environments).

The default task will watch for changes and execute tests whenever a change is detected. It will also execute tasks immediately without waiting for a change.

Custom Environment Variables

As mentioned above an object provided underneath the env options key will allow you to specify a custom environment. This is useful, for example, to run your tests in a different NODE_ENV than the default. Such a gulp task would look like:

var gulp = require('gulp'),
    mocha = require('gulp-spawn-mocha');

gulp.task('test', function() {
  return gulp
    .src(['test/*.test.js'])
    .pipe(mocha({
      env: {'NODE_ENV': 'test'}
    }));
});

This or gulp-mocha?

The original gulp-mocha is fine in most circumstances. If you need your tests to run as a separate process (or a separate process is simply your preference for the reasons specified above) or you need to use a custom version of Mocha (e.g., a fork with bug fixes or custom functionality) then you should use this plugin.

License

The MIT License

Copyright (c) 2014 Kenneth Powers

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.