toBeInstanceOf( Function ) not working as expected.

[trusktr]

Jest 22.4.3

I've got this test, that works:

    expect( typeof bar.method ).toBe( 'function' ) // it works

but then this fails:

    expect( bar.method ).toBeInstanceOf( Function )

with output:

    expect(value).toBeInstanceOf(constructor)

    Expected value to be an instance of:
      "Function"
    Received:
      [Function method]
    Constructor:
      "Function"

      270 |     console.log('1')
      271 |     expect( typeof bar.method ).toBe( 'function' )
    > 272 |     expect( bar.method ).toBeInstanceOf( Function )
      273 |
      274 |     Bar = Class({
      275 |         method() {}

Seems like it should not fail.

[trusktr]

I can make a repro if needed, but first let me know if I'm expecting something I shouldn't be expecting (no pun intended! 😊 ).

[SimenB]

How is method created?

[trusktr]

comment deleted (I made a mistake in this comment, but not in the original post)

[trusktr]

@SimenB method is created something like this:

let o = {
  method() { ... }
}

then eventually

expect( o.method ).toBeInstanceOf( Function )

[trusktr]

Okay, nevermind, I didn't make a mistake in my second comment.

I've got code like this that I can make my test pass with:

    // strange!
    expect( typeof result ).toBe( 'object' )
    expect( result ).not.toBeInstanceOf( Object )
    expect( result.constructor.name ).toBe( 'Object' )
    expect( result.constructor ).not.toBe( Object )

result is a simple object literal that is returned from a function that I've imported from another file.

[SimenB]

Might be #2549?

[trusktr]

Yep, seems like it might be the same thing.

[SimenB]

Closing as dupe, then. Follow that for updates (hope to have it solved for jest 23)

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