Angular 4 Unit test error - Failed to execute 'send' on 'XMLHttpRequest': Failed to load 'ng:///DynamicTestModule/LoginComponent.ngfactory.js'

Question

I am writing some unit tests for my component and i am getting this cryptic error message. I found a similar question at Angular 2 unit testing - getting error Failed to load &#

Answer 1

This is a problem with the Angular Cli version 1.2.2 or newer. Run your test with --sourcemaps=false and you will get the right error messages.

In Angular 4-5

• ng test --sourcemaps=false
  

  or

• ng test -sm=false
  

In Angular 6+

• ng test --source-map=false
  

See details here: https://github.com/angular/angular-cli/issues/7296