Mock navigator language in specific tests

Question

I am using Jasmine for testing JavaScript code and I was wondering if there is a way to set navigator language (or the browser language) for specific tests?

score 11 · Answer 1 · edited May 23 '17 at 10:28

11

As described in Mocking a useragent in javascript?, you can:

  navigator.__defineGetter__('language', function(){
      return 'foo';
  });

Or, you can use the more modern:

  Object.defineProperty(navigator, 'language', {
      get: function() {return 'bar';}
  });

edited May 23 '17 at 10:28

Community

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1

answered Jul 14 '16 at 19:08

abendigo

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With the more modern, I got this issue: Attempting to change access mechanism for an unconfigurable property. defineProperty@[native code] – Pierre Trollé Nov 13 '17 at 20:47
Similar error here: TypeError: Cannot redefine property: language at Function.defineProperty () – ffxsam Aug 03 '18 at 19:10
Object.define will not work in this case because `navigator` read only and that property is non-configurable, ie it's `configurable` attribute is set to false. – toads Feb 18 '21 at 18:37

score 4 · Answer 2 · answered Oct 28 '20 at 09:41

The answer from @abendigo works but it would indeed show 'Cannot redefine property' when you're trying to overrule the property twice.

In the post that he linked to they suggested to add configurable: true, so:

Object.defineProperty(navigator, 'language', {
  get: function() { return 'bar'; }, // Or just get: () => 'bar',
  configurable: true
});

Btw, a getter is not a must, you can also use a value notation:

Object.defineProperty(navigator, 'language', {
  value: 'bar',
  configurable: true
});

Mock navigator language in specific tests

2 Answers2

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