$httpBackend cannot mock binary blob responses at IE11 (InvalidStateError)

[yneves]

I found this issue running tests with karma at IE11 / Win8.1.

When i try to mock a blob response with $httpBackend.expect, i got InvalidStateError.

I dig and found that this happens because of the angular.copy which clones fake response data.

If i hack angular.copy with something like this the error stops.

if (isBlob(source)) {
    destination = new Blob([source]);
} else if (isArray(source)) {

[jurko-gospodnetic]

This is not browser specific. And pretty much prevents your from mocking HTTP requests with Blob responses. :-(

And it's related to the issue in pull request #5415, but where that one is only concerned with using the ng-mocks in pass-through mode for e2e testing.

[gkalpak]

@jurko-gospodnetic, I couldn't reprocude it just by angular.copying and Blob. Could you create a live demo of the issue (e.g. using CodePen, Plnkr etc) ?

#5415, although about $httpBackend and Blobs, is about a totally different problem.

[jurko-gospodnetic]

The shortest way to reproduce the problem is to just use the following one-liner:

angular.copy(new Blob(['bright side of life'])).slice();

And here's a plnkr reproducing the error: http://plnkr.co/xenwdKodooTrYO7VG2P2

It shows that you can't treat the almost-blob API response object you get from ng-mock as a true blob, while you can do so with the original blob given to ng-mock in its expectation. It also shows how you can not do so with an almost-blob object you get by calling angular.copy() on an actual blob object.

And if calling .slice() on it does not faze you, try using the FileReader interface to get at the blob's content, e.g. by using fileReader.readAsText() and hooking its onload (for success) & error/onloadend (for error) events.

When calling slice() on an angular.copy() produced almost-blob using PhantomJS, you get an impossible to debug error stack:

    TypeError: Type error in /your/project/path/here.js (line 42)
        at slice ([native code])

Chrome is not much better:

TypeError: Illegal invocation
    at Object.<anonymous> (http://run.plnkr.co/plunks/xenwdKodooTrYO7VG2P2/:41:20)

while FireFox seems to play a bit nicer and says:

TypeError: 'slice' called on an object that does not implement interface Blob. in http://run.plnkr.co/plunks/xenwdKodooTrYO7VG2P2/ (line 41)
@http://run.plnkr.co/plunks/xenwdKodooTrYO7VG2P2/:41:11

and IE11 seems as uninformative as Chrome:

TypeError: Invalid calling object
   at Anonymous function (http://run.plnkr.co/plunks/xenwdKodooTrYO7VG2P2/:41:11)

[gkalpak]

@jurko-gospodnetic, thx for the reproduction. I have submitted a fix in #14064.