Enzyme contains example from Enzyme docs does not pass

[wnayes]

I've noticed a discrepancy between Enzyme's documentation and the behavior with this adapter. The difference doesn't seem to be explained by the current list of differences.

I'm looking specifically at this API:
https://airbnb.io/enzyme/docs/api/ShallowWrapper/contains.html

And these examples:

const wrapper = shallow((
  <div>
    <div data-foo="foo" data-bar="bar">Hello</div>
  </div>
));

expect(wrapper.contains(<div data-foo="foo" data-bar="bar">Hello</div>)).to.equal(true);

expect(wrapper.contains(<div data-foo="foo">Hello</div>)).to.equal(false);
expect(wrapper.contains(<div data-foo="foo" data-bar="bar" data-baz="baz">Hello</div>)).to.equal(false);
expect(wrapper.contains(<div data-foo="foo" data-bar="Hello">Hello</div>)).to.equal(false);
expect(wrapper.contains(<div data-foo="foo" data-bar="bar" />)).to.equal(false);

The last expectation fails when ran with this adapter.

// This one fails:
expect(wrapper.contains(<div data-foo="foo" data-bar="bar" />)).to.equal(false);

I have a code sandbox here that demonstrates the assertion failure:
https://codesandbox.io/s/snowy-cache-q6hzg

My suspicion is that it has something to do with handling of the children prop.

[robertknight]

Thanks for the report, this does indeed look like incorrect behavior compared to the docs. It would be useful to confirm that the issue doesn't happen with the React adapter.

[ljharb]

A PR to verify that by adding those specific examples to https://github.com/airbnb/enzyme/blob/master/packages/enzyme-test-suite/test/shared/methods/contains.jsx would be happily accepted :-)

[mq2thez]

Hey, looks like this hasn't gotten any responses in a bit, but I can confirm that in my testing, the React adapter would fail on differences in the children and the Preact adapter does not appear to properly check against the children.