Testing FileSaver in Angular 5

Question

I have imported file-saver in angular 5 application, when I am executing test cases it is giving following error:

TypeError: FileSaver.saveAs is not a function

Spec.ts:
import FileSaver from 'file-saver';

.ts
import FileSaver from 'file-saver';
FileSaver.saveAs(blob, filename);

How to mock filesaver in test cases.

print out FileSaver with console.log and check if saveAs function exist into its prototype — Radonirina Maminiaina, Mar 25 '18 at 18:42
This could be useful: https://stackoverflow.com/questions/44686077/how-to-use-jest-to-test-file-download/44692287#44692287 — R. Richards, Mar 25 '18 at 18:46
@RadonirinaMaminiaina It is "undefined" when I console FileSaver. I am new to Angular 2 Testing, could you please let me know how I can get FileSaver in Spec.ts — Sreekanth Reddy, Mar 25 '18 at 19:54
Try this it's working for me. "import { saveAs } from 'file-saver/FileSaver';" — Gavishiddappa Gadagi, Mar 26 '18 at 06:25

score 15 · Accepted Answer · answered Dec 10 '18 at 01:27

15

This works in Angular 7, so I'm guessing it will work in NG5. The first thing is to import FileSaver using the 'as' syntax in both the component and the spec:

import * as FileSaver from 'file-saver';

Then in the spec beforeEach:

spyOn(FileSaver, 'saveAs').and.stub();

answered Dec 10 '18 at 01:27

Craig

932
1
11
21

2

This seems to have (suddenly) stopped working for me as a mechanism to stub saveAs method. Anyone else observing something similar? – James Robinson May 24 '21 at 10:43

Testing FileSaver in Angular 5

1 Answers1

Linked