title: The "path" argument must be of type string. Received type object - Angular 7
body: <p>I try to run test on my angular project typing </p>
  
  <pre><code>ng test --browsers=PhantomJS
  </code></pre>
  
  <p>Before, I must install phantomjs manually using command</p>
  
  <pre><code>npm install phantomjs-prebuilt@2.1.16 -ignore-scripts
  </code></pre>
  
  <p>But after <code>ng test --br ...</code> I receive this error</p>
  
  <blockquote>
    <p>23 05 2019 08:08:28.194:ERROR [config]: Error in config file!
     TypeError [ERR_INVALID_ARG_TYPE]: The "path" argument must be of type string. Received type object
        at validateString (internal/validators.js:125:11)
        at Object.extname (path.js:1365:5)
        at phantomJSExePath (/gui-build/node_modules/karma-phantomjs-launcher/index.js:18:12)
        at Object. (/gui-build/node_modules/karma-phantomjs-launcher/index.js:107:12)
        at Module._compile (internal/modules/cjs/loader.js:701:30)
        at Object.Module._extensions..js (internal/modules/cjs/loader.js:712:10)
        at Module.load (internal/modules/cjs/loader.js:600:32)
        at tryModuleLoad (internal/modules/cjs/loader.js:539:12)
        at Function.Module._load (internal/modules/cjs/loader.js:531:3)
        at Module.require (internal/modules/cjs/loader.js:637:17)
        at require (internal/modules/cjs/helpers.js:22:18)....</p>
  </blockquote>
  
  <p>How can I fix this?</p>
  
  <blockquote>
    <p>ENVIRONMENT: Angular CLI: 7.3.9
     Node: 10.15.3
    OS: linux x64
    Angular: 7.2.15</p>
  </blockquote>
  
  <p><strong>karma.conf.js</strong></p>
  
  <pre><code> // Karma configuration
   // Generated on Wed Oct 24 2018 11:15:29 GMT+0200 (Central European Daylight Time)
   const path = require('path');
  
   module.exports = function(config) {
   config.set({
   files: [
    'src/**/*.js',
    'src/test/**/*.js'
   ],
   basePath: '',
   frameworks: ['jasmine'],
  
   preprocessors: {
    '!(test)/**/*.js': 'coverage'
   },
  
   plugins: [
    require('karma-jasmine'),
    require('karma-chrome-launcher'),
    require('karma-jasmine-html-reporter'),
    require('karma-coverage-istanbul-reporter'),
    require('@angular/cli/plugins/karma')
   ],
  
   client: {
    clearContext: false
   },
  
   coverageIstanbulReporter: {
    reports: [ 'html', 'lcovonly', 'text-summary' ],
    dir: path.join(__dirname, 'coverage'),
    skipFilesWithNoCoverage: true,
    fixWebpackSourcePaths: true
   },
  
   angularCli: {
    environment: 'dev',
    config: '@angular/cli'
   },
  
   // list of files to exclude
   exclude: [
   ],
  
   reporters: ['progress', 'kjhtml'], 
   port: 9876,
   colors: true,
   logLevel: config.LOG_INFO,
   autoWatch: false,
   browsers: ['Chrome'],
   singleRun: true,
   concurrency: Infinity
   })
  } ;
  </code></pre>
  
  <p><strong>package.json</strong> </p>
  
  <pre><code>{
   "name": "gui",
   "version": "0.0.0",
   "scripts": {
   "ng": "ng",
   "start": "ng serve",
   "build": "ng build",
   "release": "ng build --prod",
   "test": "ng test",
   "lint": "ng lint",
   "e2e": "ng e2e",
   "version": "git add -A package.json &amp;&amp; git commit",
   "postversion": "rm -rf build/temp"
   },
   "private": true,
   "dependencies": {
   "@angular/animations": "^7.2.15",
   "@angular/common": "^7.2.15",
   "@angular/compiler": "^7.2.15",
   "@angular/core": "^7.2.15",
   "@angular/forms": "^7.2.15",
   "@angular/http": "^7.2.15",
   "@angular/platform-browser": "^7.2.15",
   "@angular/platform-browser-dynamic": "^7.2.15",
   "@angular/router": "^7.2.15",
   "@ng-bootstrap/ng-bootstrap": "^3.3.0",
   "core-js": "^2.5.4",
   "font-awesome": "^4.7.0",
   "intl": "^1.2.5",
   "lodash": "^4.17.11",
   "rxjs": "^6.5.2",
   "tslib": "^1.9.0",
   "zone.js": "~0.8.29"
   },
   "devDependencies": {
   "@angular-devkit/build-angular": "~0.13.0",
   "@angular/cli": "~7.3.9",
   "@angular/compiler-cli": "^7.2.15",
   "@angular/language-service": "^7.2.15",
   "@types/jasmine": "~2.8.6",
   "@types/jasminewd2": "~2.0.3",
   "@types/node": "~8.9.4",
   "codelyzer": "~4.2.1",
   "jasmine-core": "^2.99.1",
   "jasmine-spec-reporter": "^4.2.1",
   "karma": "^1.7.1",
   "karma-chrome-launcher": "^2.2.0",
   "karma-coverage-istanbul-reporter": "^2.0.4",
   "karma-jasmine": "^1.1.2",
   "karma-jasmine-html-reporter": "^0.2.2",
   "karma-phantomjs-launcher": "^1.0.4",
   "phantomjs-prebuilt": "^2.1.16",
   "protractor": "~5.3.0",
   "ts-node": "~5.0.1",
   "tslint": "~5.9.1",
   "typescript": "~3.2.4"
   }
  }
  </code></pre>
  
  <p>How can I fix it? Thanks in advance</p>