Karma run test cases double times - unit-testing

Question

I am using karma for angular 2 unit testing.Its works fine to me but I have one thing which I don't know why its happening.With karma when I run test cases, every function which I test run two times.I knew this problem when I print console.log on that function which I used in test case.I don't know why this happened to me.Please help me.
I am using it with webpack.
webpack: bundle is now VALID.
17 10 2016 10:02:20.102:INFO [karma]: Karma v1.2.0 server started at http://localhost:9876/
17 10 2016 10:02:20.106:INFO [launcher]: Launching browser Chrome with unlimited concurrency
17 10 2016 10:02:20.188:INFO [launcher]: Starting browser Chrome
17 10 2016 10:02:40.019:INFO [Chrome 52.0.2743 (Linux 0.0.0)]: Connected on socket /#bNq05S_5S6il-eenAAAA with id 72225563
LOG: 'headers = {"content-type":["application/json"]}'
LOG: 'headers = {"content-type":["application/json"]}'
Global Service : Login Authentication
✔ Should have operator login Authentication
LOG: 'headers = {"content-type":["application/json"],"authorization":["Token ad42hjk234bad8808"]}'
LOG: 'headers = {"content-type":["application/json"],"authorization":["Token ad42hjk234bad8808"]}'
LOG: 'catch 400 = {"_body":"{\"username\":\"xyz#gmail.com\",\"password\":\"761e768a501c30ea8e38\"}","status":400,"ok":false,"statusText":null,"headers":null,"type":null,"url":null}'
LOG: 'catch 400 = {"_body":"{\"username\":\"xyz#gmail.com\",\"password\":\"761e768a501c30ea8e38\"}","status":400,"ok":false,"statusText":null,"headers":null,"type":null,"url":null}'
✔ Should be call error page if login credential wrong
Global Utils : Meta urls API
✔ Should have get Meta urls
LOG: 'page error'
LOG: 'page error'
✔ If get Empty Response of MetaUrls with status code 200
LOG: 'page error'
LOG: 'page error'
✔ If get Empty Response of MetaUrls with status code 400
LOG: 'page error'
LOG: 'page error'
✔ Should not have get Meta urls data with status code 404
Finished in 0.473 secs / 0.431 secs
SUMMARY:
✔ 6 tests completed
karma.conf.js
/**
* #author: #AngularClass
*/
module.exports = function (config) {
var testWebpackConfig = require('./config/webpack.test.js')({env: 'test'});
var configuration = {
// base path that will be used to resolve all patterns (e.g. files, exclude)
basePath: '',
/*
* Frameworks to use
*
* available frameworks: https://npmjs.org/browse/keyword/karma-adapter
*/
frameworks: ['jasmine'],
// list of files to exclude
exclude: [],
/*
* list of files / patterns to load in the browser
*
* we are building the test environment in ./spec-bundle.js
*/
files: [
{ pattern: './config/spec-bundle.js', watched: false }
],
/*
* preprocess matching files before serving them to the browser
* available preprocessors: https://npmjs.org/browse/keyword/karma-preprocessor
*/
preprocessors: {
'./config/spec-bundle.js': ['coverage', 'webpack', 'sourcemap'],
},
// Webpack Config at ./webpack.test.js
webpack: testWebpackConfig,
coverageReporter: {
type: 'in-memory'
},
remapCoverageReporter: {
'text-summary': null,
json: './coverage/coverage.json',
html: './coverage/html'
},
// Webpack please don't spam the console when running in karma!
webpackMiddleware: {stats: 'errors-only'},
/*
* test results reporter to use
*
* possible values: 'dots', 'progress'
* available reporters: https://npmjs.org/browse/keyword/karma-reporter
*/
reporters: ['mocha', 'coverage', 'remap-coverage'],
// 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
* available browser launchers: https://npmjs.org/browse/keyword/karma-launcher
*/
browsers: [
'Chrome'
],
customLaunchers: {
ChromeTravisCi: {
base: 'Chrome',
flags: ['--no-sandbox']
}
},
plugin: [
'karma-coverage',
'karma-mocha-reporter',
'karma-remap-coverage',
'karma-sourcemap-loader',
'istanbul-instrumenter-loader'
],
/*
* Continuous Integration mode
* if true, Karma captures browsers, runs the tests and exits
*/
singleRun: true
};
if (process.env.TRAVIS) {
configuration.browsers = [
'ChromeTravisCi',
'Chrome'
];
}
config.set(configuration);
};
spec-bundle.js
/**
* #author: #AngularClass
*/
/*
* When testing with webpack and ES6, we have to do some extra
* things to get testing to work right. Because we are gonna write tests
* in ES6 too, we have to compile those as well. That's handled in
* karma.conf.js with the karma-webpack plugin. This is the entry
* file for webpack test. Just like webpack will create a bundle.js
* file for our client, when we run test, it will compile and bundle them
* all here! Crazy huh. So we need to do some setup
*/
Error.stackTraceLimit = Infinity;
require('core-js/es6');
require('core-js/es7/reflect');
// Typescript emit helpers polyfill
require('ts-helpers');
require('zone.js/dist/zone');
require('zone.js/dist/long-stack-trace-zone');
require('zone.js/dist/proxy'); // since zone.js 0.6.15
require('zone.js/dist/sync-test');
require('zone.js/dist/jasmine-patch'); // put here since zone.js 0.6.14
require('zone.js/dist/async-test');
require('zone.js/dist/fake-async-test');
// RxJS
require('rxjs/Rx');
var testing = require('#angular/core/testing');
var browser = require('#angular/platform-browser-dynamic/testing');
testing.TestBed.initTestEnvironment(
browser.BrowserDynamicTestingModule,
browser.platformBrowserDynamicTesting()
);
/*
* Ok, this is kinda crazy. We can use the context method on
* require that webpack created in order to tell webpack
* what files we actually want to require or import.
* Below, context will be a function/object with file names as keys.
* Using that regex we are saying look in ../src then find
* any file that ends with spec.ts and get its path. By passing in true
* we say do this recursively
*/
var testContext = require.context('../src', true, /\.spec\.ts/);
/*
* get all the files, for each file, call the context function
* that will require the file and load it up here. Context will
* loop and require those spec files here
*/
function requireAll(requireContext) {
return requireContext.keys().map(requireContext);
}
// requires and returns all modules that match
var modules = requireAll(testContext);

Answer 1

I've had the same problem and it's because the '*.spec.js' files need to be accessible but not included, so you have to do something like this:
files: [
{ pattern: './config/spec-bundle.js', watched: false },
{ pattern: '**/*.spec.js', included: false, served: true, watched: false }
]
This is the source I've found: https://medium.com/#SchizoDuckie/so-your-karma-tests-run-twice-this-is-what-you-need-to-do-be74ce9f257e#.lqrkf24ty