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?

Answer 1

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().