Javascript 因果报应不存在'；不尊重浏览器的属性

我试图只在一个浏览器中运行单元测试，但karma在Chrome中继续运行它们。我的配置如下所示：

module.exports = function(config) {
config.set({

// base path, that will be used to resolve files and exclude
basePath: '../../',


// frameworks to use
frameworks: ['jasmine', 'requirejs'],


// list of files / patterns to load in the browser
files: [
  'test/test-main.js',
  {pattern: 'js/**/*.js', included: false},
  {pattern: '../Common/js/**/*.js', included: false},
  {pattern: '../Common/js/spec/*.spec.js', included: false},
  {pattern: 'js/spec/*.spec.js', included: false},
  {pattern: 'js/*.js', included: false}
],


// list of files to exclude
exclude: [
  'js/main*.js',
  'js/build.js'
],


// test results reporter to use
// possible values: 'dots', 'progress', 'junit', 'growl', 'coverage'
reporters: ['progress'],


// web server port
port: 9876,


// enable / disable colors in the output (reporters and logs)
colors: true,


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


// enable / disable watching file and executing tests whenever any file changes
autoWatch: false,


// Start these browsers, currently available:
// - Chrome
// - ChromeCanary
// - Firefox
// - Opera (has to be installed with `npm install karma-opera-launcher`)
// - Safari (only Mac; has to be installed with `npm install karma-safari-launcher`)
// - PhantomJS
// - IE (only Windows; has to be installed with `npm install karma-ie-launcher`)
browsers: ['PhantomJS'],


// If browser does not capture in given timeout [ms], kill it
captureTimeout: 60000,


// Continuous Integration mode
// if true, it capture browsers, run tests and exit
singleRun: true
});
};

为什么会这样？有没有办法只在IE中运行测试

谢谢