feat: export container from render

[klekowskim]

Summary

Exports root test instance from render method. It is a change mentioned in this feature request: #566

After this change it is possible to get test instance from render method:

const { container } = render(<View />);

[klekowskim]

I can also change it to export container, instead of the root. To do that probably I would need to add internal wrapper, as it was in the second library here.

In that case the API would be more like in the react-testing-library.

[mikeduminy]

+1 to this change, and +1 on adding container and baseElement

[mdjastrzebski]

I guess I am in favor of exposing container instead of root. Getting root element from contains is very easy and we have maintain api between RTL and RNTL with all benefits of such (code and knowledge sharing, etc).

Regarding wrapping of root element, I think that wrapping it in plain View should do the cases TL/RN v6 did wrap it in AppContainer from ''react-native/Libraries/ReactNative/AppContainer' but reading the code of AppContainer this seems not useful as it deals with low-level RN stuff like profiling, logbox, inspector, etc.

[klekowskim]

@thymikee What do you think? I can adjust it but I'd like to know if it is going to be merged 😄

[thymikee]

Let's do it. Like @mdjastrzebski said

[thymikee]

Removed the default wrapper, because it's orthogonal to returning the root instance and would require us to release this feature in a major release.
I left the peer dep on react-native, because it should be there anyway.

Thanks for the contribution!

[mdjastrzebski]

Overall looks good, consider adding testID/nativeID checks in tests

[pvinis]

I just tried to use this and saw a couple of issues:

• typings/index.d.ts is not updated to contain the container.
• ReactTestInstance is not exported in typings/index.d.ts so I can't add this as a type to my helper test function
• I need access to ErrorWithStack and getNodeByText. Is there a way to use these on container?

[pvinis]

@thymikee are these 👆 done or being worked on, or would it be better if I make an issue for these?

[thymikee]

I don't think these are addressed. Please create an issue :)