Expect assertions type error -> expect(...).toExist is not a function

Question

I'm testing a NodeJS app. I encountered this error when I ran the tests. The test script is below:

.expect((res) => {
    expect(res.headers['x-auth']).toExist();
    expect(res.body._id).toExist();
    expect(res.body.email).toBe(email);
})

The error showed:

TypeError: expect(...).toExist is not a function

How can I resolve this issue?

expect.js doesn't have any method called `toExist()`. You can read its documentation here: https://github.com/Automattic/expect.js — Sven, Sep 26 '17 at 23:38
@Svenskunganka following this documentation for testing .. other assertions are working fine -> https://github.com/mjackson/expect — Md Ashiqur Rahman, Sep 27 '17 at 17:16

score 34 · Accepted Answer · edited May 12 '21 at 23:44

34

The expect assertion library has changed ownership. It was handed over to the Jest team, who in their infinite wisdom, created a new API.

You must now use toBeTruthy()instead of toExist().

You can still install expect as before, npm install expect --save-dev, which is currently at version 21.2.1. Most methods names will remain unchanged except for a few, including toExist().

edited May 12 '21 at 23:44

ggorlen

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answered Sep 28 '17 at 02:23

AKenny

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not worked :/ expect(...). toBeTruthy() is not a function – Md Ashiqur Rahman Sep 29 '17 at 12:08
its worked :) thanks a lot. I used .toContain() instead of .toInclude() but it does not match as expected @AKenny – Md Ashiqur Rahman Sep 30 '17 at 13:12
2

If you are testing that an object contains certain properties and values, you could try using .toMatchObject)(obj). – AKenny Sep 30 '17 at 15:40
I was just looking for this answer. Thanks a lot! :) – Himanshu Aggarwal Nov 16 '17 at 06:54

score 2 · Answer 2 · answered May 13 '19 at 16:08

2

If you are using Jest you can also use 'toBeDefined()'

answered May 13 '19 at 16:08

Ankit

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Expect assertions type error -> expect(...).toExist is not a function

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