Change props on same component instance, reprise

[eschiebel]

• react-testing-library version:5.4.4
• react version:16.7.0
• node version: v8.10.0
• npm (or yarn) version: yarn 10.1.1

Relevant code or config:

in a previously closed ticket #65 (comment) you suggest calling

render(<C {...newProps}/>, container)

to rerender with new props, but when I do this, the existing instance is not updated, but I get a new instance of the component.

What you did:

1. set a breakpoint in my component's constructor, render, and componentDidUpdate functions
2. call {{const {container} = render()}}
3. The constructor and render breakpoints are hit. In render, I set window.xxx=this
4. call render(<C value="177"/>, container)
5. I see the constructor and render called. componentDidUpdate is not called and window.xxx!==this

What happened:

Reproduction:

https://codesandbox.io/s/jj56q52rqw

You can see that the test output renders 2 instances of the Hello component, and that componentDidUpdate is never called

Problem description:

I don't know how to test property change behavior on my components

Suggested solution:

[puemos]

render(<Hello name="Jack" />, container);

probably needs to be:

render(<Hello name="Jack" />, {container});

https://codesandbox.io/s/okyw07246

[alexkrolick]

Thanks for catching that @puemos!