Rendering in Snapshot tests

[PauliusLiekis]

Hi,

I'm having problems with GroupedVirtuoso in UnitTests. The first issue that I ran into was this:

Error: Uncaught [Invariant Violation: Invalid hook call. Hooks can only be called inside of the body of a function component. This could happen for one of the following reasons:
1. You might have mismatching versions of React and the renderer (such as React DOM)
2. You might be breaking the Rules of Hooks
3. You might have more than one copy of React in the same app
See https://fb.me/react-invalid-hook-call for tips about how to debug and fix this problem.]

This happens when rendering an empty list.
I made sure that the rendering of functional-components and hooks works fine. The issue seems to be specific to GroupedVirtuoso.

I tried to narrow down the issue but run into another problem:

TypeError: Cannot read property 'removeEventListener' of null

  46 |         elRef.current = theRef
  47 |       } else {
> 48 |         elRef.current!.removeEventListener('scroll', onScroll)
     |                        ^
  49 |       }
  50 |     },
  51 |     [onScroll]

  at src/VirtuosoScroller.tsx:48:24

The latter issue was reproduced in master of react-virtuoso using the attached test:
Snapshot.test.tsx.zip

You will need to add these two dependencies:

"@types/react-test-renderer": "^16.9.2",
"react-test-renderer": "^16.13.1",

One of the reasons why we started on this path is that sometimes we get calls to item and group with out-of-bounds indices. I don't have more details on that yet...

[petyosi]

Thanks for the report, I will give this a try.

[petyosi]

@PauliusLiekis - can you please test 0.16.1? Let me know if you discover more issues down the road with the hook usage.

[PauliusLiekis]

Sorry for taking forever to respond. I can confirm that I no longer reproduce removeEventListener issue with latest code.

However, I still have the other one:

Error: Uncaught [Invariant Violation: Invalid hook call. Hooks can only be called inside of the body of a function component. This could happen for one of the following reasons:

It has something to do with passing empty array of groups to it. I haven't managed to make a small repro case for it yet :/ I'll let you know once/if I do.