karma-coverage files not created while singleRun = true - angularjs

Question

I am using Karma to run my unit tests and am now trying to incorporate karma-coverage into my process.
I am using PhantomJS to run the tests with singleRun: true. Whenever I do this, my code coverage reporter does not seem to be running. If I set singleRun: false, the folder and files are created.
Why is the karma coverage tool not running?
Here is my config file:
module.exports = function (config) {
config.set({
basePath: '',
frameworks: ['mocha', 'requirejs', 'sinon-chai'],
files: [
{ pattern: 'bower_components/angular/angular.js', included: false },
{ pattern: 'bower_components/jquery/dist/jquery.js', included: false },
{ pattern: 'bower_components/angular-mocks/angular-mocks.js', included: false },
{ pattern: '**/*.js', included: false },
{ pattern: 'KarmaTests/test-main.js', included: true },
{ pattern: 'KarmaTests/**/*Test*.js', included: false }
],
preprocessors: {
'KarmaTests/*/*.js': ['coverage']
},
reporters: ['progress', 'coverage'],
coverageReporter: {
type: 'html',
dir: '_testCoverage/',
file: 'cover.html'
},
port: 9876,
colors: true,
logLevel: config.LOG_INFO,
autoWatch: true,
browsers: ['PhantomJS'],
//files are created when false, are not when true
singleRun: false
});
};

Answer 1

Preprocessor is intended to map the source files, not the test files. Do the following:
Change the preprocessor pattern to:
preprocessors: {
'/**/*.js': ['coverage']
},
And add the JS files to the test mapping:
{ pattern: '**/*.js', included: true }
Rerun karma and view the results