karma coverage does not show any data

I have included the source files in the files & preprocessors section of my karma conf file. The tests run fine and the junit xml report shows the data. The html coverage just show 100% without any data. I have the similar structure for another project which is working fine but not this one. Not sure if i am missing something. Might be a very minor or silly thing i have missed.

karma.conf.js:

    module.exports = function (config) {
    config.set({
    basePath: '../../',

    frameworks: [
        'jasmine'
    ],

    // list of files / patterns to load in the browser
    files: [
        'app/js/**/*.js',
        'test/spec/**/*.js'
    ],

    preprocessors: {
        'app/js/**/*.js': ['coverage']
    },

    exclude: [],

    reporters: [ 'progress', 'junit', 'coverage' ],

    coverageReporter: {
        type: 'html',
        dir: 'test/reports/unit/coverage'
    },

    junitReporter: {
        outputFile: 'test/reports/unit/junit/junit.xml',
        suite: 'unit'
    },

    port: 9876,

    runnerPort: 9100,

    colors: true,

    logLevel: config.LOG_DEBUG,

    autoWatch: false,

    browsers: [ 'Chrome' ],

    captureTimeout: 60000,

    singleRun: true
});
};

my karma conf file is in test -> spec -> conf and source files are in app -> js -> controllers/directives/services

the debug log shows its loading all the files in preprocessors but the report does not show any data “No data to display”.

[stsvilik]

I’ve had similar issue with browserify + babel + karma. Take a look here.

Key to my setup was to add [“istanbul”] into babel plugins.

[andy-dorman]

I’m not totally sure how related this is but after running into the same issues as others on this thread I looked back into a project I worked on that had this working.

The vital config for me was to require browserify-istanbul in my karma.config.js:

var istanbul = require("browserify-istanbul");

and set this config:

browserify: {
  transform: [
    [
      istanbul({
      ignore: ["node_modules/**", "**/*.spec.js"],
      includeUntested: false,
      defaultIgnore: true
      }),
      { global: true }
    ]
  ]
}

Not totally sure what this points to other than a possible issue with karma-browserify perhaps, but maybe it can help someone…