How to setup Karma runner code coverage?

Question

I am attempting to get Karma runner to generate cobertura formatted code coverage reports during a Jenkins build. I can get it to generate a coverage.xml file, but it does not actually have any coverage data. It appears (using LOG_DEBUG) that the coverage preprocessor is not running.

The relevant pieces from my karma.conf.js file are:

files = [   JASMINE,   JASMINE_ADAPTER,   'app/components/angular/angular.js',   'app/components/angular-mocks/angular-mocks.js',   'tmp/scripts/**/*.js',   'tmp/spec/**/*.js' ];  preprocessors = {   'tmp/scripts/**/*.js': 'coverage' };  // test results reporter to use // possible values: 'dots', 'progress', 'junit' reporters = ['dots', 'junit', 'coverage'];  junitReporter = {   outputFile: 'test-results.xml' };  coverageReporter = {   type: 'cobertura',   dir: 'coverage/',   file: 'coverage.xml' }; 

(The junit report is generating fine.)

Answer 1

Apparently the karma code coverage documentation was more literal than I thought. Changing my preprocessors configuration to

preprocessors = {   '**/tmp/scripts/**/*.js': 'coverage' }; 

(notice the preceding **/) did the trick. I am not sure why the syntax is different for the files array and the preprocessors object ('tmp/scripts/**/*.js' vs. '**/tmp/scripts/**/*.js').