Unable to run Coverage with Karma

问题:

I'm trying to run coverage with karma, and I get the warning: WARN [preprocess]: Can not load "coverage", it is not registered!

I thought I installed coverage when I ran 'npm install -g karma-coverage --save-dev'

Here's my config file:

module.exports = function(config) {
      config.set({
        // base path, that will be used to resolve files and exclude
        basePath: '',

        frameworks: ['jasmine'],

        // list of files / patterns to load in the browser
        files: [
                bunch of files..
        ],

        // list of files to exclude
        exclude: [],

        // use dots reporter, as travis terminal does not support escaping sequences
        // possible values: 'dots', 'progress'
        // CLI --reporters progress
        reporters: ['progress', 'coverage'],

        junitReporter: {
          // will be resolved to basePath (in the same way as files/exclude patterns)
          outputFile: 'test-results.xml'
        },

        // web server port
        // CLI --port 9876
        port: 9876,

        // enable / disable colors in the output (reporters and logs)
        // CLI --colors --no-colors
        colors: true,

        // level of logging
        // possible values: config.LOG_DISABLE || config.LOG_ERROR || config.LOG_WARN || config.LOG_INFO || config.LOG_DEBUG
        // CLI --log-level debug
        logLevel: config.LOG_INFO,

        // enable / disable watching file and executing tests whenever any file changes
        // CLI --auto-watch --no-auto-watch
        autoWatch: true,

        // Start these browsers, currently available:
        // - Chrome
        // - ChromeCanary
        // - Firefox
        // - Opera
        // - Safari (only Mac)
        // - PhantomJS
        // - IE (only Windows)
        // CLI --browsers Chrome,Firefox,Safari
        browsers: ['ChromeCanary'],

        // If browser does not capture in given timeout [ms], kill it
        // CLI --capture-timeout 5000
        captureTimeout: 20000,

        // Auto run tests on start (when browsers are captured) and exit
        // CLI --single-run --no-single-run
        singleRun: true,

        // report which specs are slower than 500ms
        // CLI --report-slower-than 500
        reportSlowerThan: 500,

        // compile coffee scripts
        preprocessors: {
            'someFileName': ['coverage'],
        },

        plugins: [
          'karma-jasmine',
          'karma-chrome-launcher',
          'karma-firefox-launcher',
        ],

    coverageReporter: {
        'type' : 'cobertura',
        'dir': 'coverage/'
    }

  });
};

回答1:

I got the same [WARN] because the plugin 'karma-coverage' was not defined inside the plugins of the config, try to see if adding it fixes your warning, not sure if it will fix your full problem.

plugins: [
  'karma-jasmine',
  'karma-coverage',
  'karma-chrome-launcher',
  'karma-firefox-launcher',
],

UPDATE:
I also had a different problem when running the coverage, caused by istanbul, my error was

[coverage]: [TypeError: Cannot set property 'covered' of undefined]

After having a look what istanbul was doing it turned out that the paths to some of my js unit files were outdated in the preprocessors.

It was doing some of the coverage reports but it was not generating deep coverage reports for all files hence the error. Once I fixed the paths it was all good.

    preprocessors : {
        '**/app/js/*/*.js' : 'coverage',
        '**/app/js/modules/*/*.js' : 'coverage',
        '**/app/js/services/*/*.js' : 'coverage'
    }, 

回答2:

For what it's worth, this works fine for me. Installed with:

npm install -g karma
npm install -g karma-coverage

Config in karma.config.js:

module.exports = function(config) {
  config.set({
    basePath: '',
    frameworks: ['jasmine'],
    files: ['app.js','tests.js'],
    preprocessors: { 'app.js': 'coverage' },
    reporters: ['dots', 'coverage'],
    port: 9876,
    colors: true,
    logLevel: config.LOG_INFO,
    autoWatch: true,
    browsers: ['Chrome'],
    captureTimeout: 60000,
    singleRun: false
  });
};

Run with karma start karma.config.js.

回答3:

For those who are using grunt test to run the karma test, and have the problem of coverage plugin not loaded issue. Please add the plugins setting into your Gruntfiles.js karama task, i.e.

// Test settings
karma: {
  unit: {
    configFile: 'test/karma.conf.js',
    singleRun: true,
    plugins:[
      'karma-jasmine',
      'karma-coverage',
      'karma-phantomjs-launcher'
    ],
  }
}

回答4:

I had the same issue, until I moved karma.conf.js into the same directory as package.json, then it worked.

回答5:

This problem is described in this answer.

When using a globally installed karma it doesn't load the locally installed plugins. Using node_modules/.bin/karma to start the tests should solve this problem.

The installation of the coverage module in the global "namespace" also works but is probably not what you want.

回答6:

I installed karma-coverage globally it worked for me :-)

npm install -g karma-coverage

回答7:

I think the correct solution is

DON'T install karma globally

INSTALL karma-cli globally and install karma locally

npm i -g karma-cli

That's the problem then, you should use karma-cli globally, http://karma-runner.github.io/0.12/intro/installation.html If you install karma globally it doesn't use the local installation.

reference: github