Angular4 junit test with karma : does not load javascript

I've converted my project to angular 4 / angular-cli 1.0.0 And since then, I have a strange behavior when I want to run the tests

my config :

 @angular/cli: 1.0.1 
 node: 7.8.0
 os: win32 x64
 @angular/common: 4.0.3
 @angular/compiler: 4.0.3
 @angular/core: 4.0.3
 @angular/forms: 4.0.3
 @angular/http: 4.0.3
 @angular/platform-browser: 4.0.3
 @angular/platform-browser-dynamic: 4.0.3
 @angular/router: 4.0.3
 @angular/cli: 1.0.1
 @angular/compiler-cli: 4.0.3

my karma.config.js

 module.exports = function (config) {
   config.set({
   basePath: '',
   frameworks: ['jasmine', '@angular/cli'],
   plugins: [
    require('karma-jasmine'),
    require('karma-phantomjs-launcher'),
    require('karma-firefox-launcher'),
    require('karma-chrome-launcher'),
    require('@angular/cli/plugins/karma'),
    require('karma-jasmine-html-reporter'),
    require('karma-coverage-istanbul-reporter')
    ],
   client:{
       clearContext: false // leave Jasmine Spec Runner output visible in 
        browser
   },
   files: [
      { pattern: './src/test.ts', watched: false }
   ],
   preprocessors: {
      './src/test.ts': ['@angular/cli']
   },
   mime: {
     'text/x-typescript': ['ts','tsx']
   },   
   coverageIstanbulReporter: {
      reports: [ 'html', 'lcovonly' ]
   },
   reporters: config.angularCli && config.angularCli.codeCoverage
          ? ['progress', 'coverage-istanbul']
          : ['progress'],
   port: 9876,
   colors: true,
   logLevel: config.LOG_INFO,
   autoWatch: true,
   browsers: ['PhantomJS','Firefox','Chrome'],
   singleRun: false
  });
 };

when i launch test with ng test --browsers Chrome No test run (nut there is no errors),it seems that he does not find any test

indeed , in browser , i don't see my javascripts

BUT when i modify one of junit test (xxx.psec.ts with an editor) (by adding a space line), the javascripts are loaded in browser

and my tests are running

why are not my tests running at first time?