connect should hoist wrapped component's propTypes if they exist

When using this HOC in development, propTypes warnings will normally appear in the console. This is great! However, if you are using shallow rendering in tests, and rely on propTypes warnings to be surfaced by your test suite, they will not be surfaced because they are not hoisted from the wrapped component.

This is further problematic if you are combining multiple HOCs on the same component, and one of them uses something like forbidExtraProps.

What do you think about adding some logic to connect that copies propTypes (and necessarily defaultProps) if they exist on the wrapped component?

cc @ljharb @barberdt

[jimbolla]

This seems solvable in userland without needing to modify connect. One could wrap connect and add the desired behavior.

[ljharb]

+1 on propTypes - copying defaultProps isn’t helpful for warnings, but it is helpful so that MyComponent.defaultProps = { ...InnerComponent.defaultProps }; isn’t a breaking change when InnerComponent changes from unwrapped → wrapped.

In other words, starting to use an HOC, or ceasing to use one, should be utterly transparent to consumers of the wrapped/unwrapped component - and one way to help ensure that is to make sure that statics, including defaultProps and propTypes, are meaningfully similar on the wrapper as on the wrapped.