ember-cli-nacho-coverage

Code coverage using Istanbul for Ember apps that works with any transpiler.

Requirements

• If using Mocha, Testem >= 1.6.0 for which you need ember-cli > 2.4.3
• If using Mirage you need ember-cli-mirage >= 0.1.13
• If using Pretender (even as a dependency of Mirage) you need pretender >= 0.11.0
• If using Mirage or Pretender, you need to set up a passthrough for coverage to be written.

Installation

• ember install ember-cli-nacho-coverage

Usage

Coverage will only be generated when an environment variable is true (by default COVERAGE) and running your test command like normal.

For example:

COVERAGE=true ember test

If you want your coverage to work on both Unix and Windows, you can do this:

npm install cross-env --save-dev

and then:

cross-env COVERAGE=true ember test

When running with parallel set to true, the final reports can be merged by using ember coverage-merge. The final merged output will be stored in the coverageFolder.

Configuration

Configuration is optional. Use ember-cli-build.js, as ember-cli-nacho-coverage.

Options

• coverageEnvVar: Defaults to COVERAGE. This is the environment variable that when set will cause coverage metrics to be generated.

• reporters: Defaults to ['lcov', 'html']. The json-summary reporter will be added to anything set here, it is required. This can be any reporters supported by Istanbul.

• excludes: Defaults to ['*/mirage/**/*']. An array of globs to exclude from instrumentation. Useful to exclude files from coverage statistics.

• coverageFolder: Defaults to coverage. A folder relative to the root of your project to store coverage results.

• parallel: Defaults to false. Should be set to true if parallel testing is being used, for example when using ember-exam with the --parallel flag. This will generate the coverage reports in directories suffixed with _<random_string> to avoid overwriting other threads reports. These reports can be joined by using the ember coverage-merge command (potentially as part of the posttest hook in your package.json).

• includeTranspiledSources: Defaults to []. Should include a list of transpiled JavaScript source extensions to be included in the coverage instrumentation. However, the compiled output is what will be instrumented so this will only be a close approximation of the source coverage.

Example

  module.exports = {
    coverageEnvVar: 'COV'
  }

Create a passthrough when intercepting all ajax requests in tests

To work, this addon has to post coverage results back to a middleware at /write-coverage.

If you are using ember-cli-mirage you should add the following:

// in mirage/config.js

  this.passthrough('/write-coverage');
  this.namespace = 'api';  // It's important that the passthrough for coverage is before the namespace, otherwise it will be prefixed.

If you are using ember-cli-pretender you should add the following:

// where ever you set up the Pretender Server

  var server = new Pretender(function () {
    this.post('/write-coverage', this.passthrough);
  });

Inspiration

This addon was inspired by ember-cli-blanket. The primary differences are that this addon uses Istanbul rather than Blanket for coverage and it instruments your application code as part of the build, when enabled.