Jest-styled-components: v7.0.0 No styles found when shallow rendering nested styled-components

[functionalDev]

When upgrading to styled-components v5 and jest-styled-components v7, we had multiple components missing styling rules in tests when shallow rendering and checking with toHaveStyleRule.

I came to the conclusion that it happens, when a styled-component has another styled-component as the root element in the mark up.
Example Test:

import { shallow } from "enzyme";

it("nested with styling", () => {
  const WrapperComponent = styled.section`
    background: papayawhip;
  `;

  const MyComponent = ({className}) => <WrapperComponent className={className} />;
  const MyStyledComponent = styled(MyComponent)`
    color: red;
  `;

  const wrapper = shallow(
    <MyStyledComponent >{sampleText}</MyStyledComponent >,
  );
  expect(wrapper).toHaveStyleRule('color', 'red');
});

In my opinion this is a very common thing when using styled-components and should be supported by this library.

Something that is probably obvious, but just to be sure I point it out: There is no test for that case in toHaveStyleRule.spec.js and it fails when I add it.

[dumbNickname]

We have exactly the same problem - any news here? We are aware of the cheap solution -> switch tests to use mount instead of shallow to make them green, but we would definitely like to avoid taking this path as it increases time needed by tests significantly.

[kennethnym]

The native version of toHaveStyleRule only tries to find style prop in the top-most level of a given styled-components like this:

component.props.styles

However, Enzyme will only render the first level and not any further, so style prop will be undefined.

If we dive three times into the given styled-components, the underlying components will be exposed, thus exposing the style prop:

component.dive().dive().dive().debug()
// <View style={{...}}
component.dive().dive().dive().prop('style')
// works

[functionalDev]

@MrCreeper1008
thx for the explaination, but I don't quite get it. If I understand properly, then I am testing the top-most level of the given styled component and not some deeper level.

I created a pull request which fixes the issue for me. The cause seems to be that the className is not retrieved properly for the case describes above. I also added a test for the use case to toHaveStyleRule.spec.js.

[kennethnym]

It works differently for react native. I forgot to put that

[probablyup]

v7.0.1 might help

[Tokimon]

I have posted a possible reason here:
https://github.com/styled-components/jest-styled-components/issues/297#issuecomment-639362675

And I currently use v7.0.2