[react-apollo] Update type for QueryRenderProps

[ganemone]

This improves the types for QueryRenderProps with respect to props.data. It correctly handles props.data being null, an empty object, or TData.

See #2172 (comment) for more context

[KevinGrandon]

👍 (Still need an approval from someone with authority obviously)

[ganemone]

cc @wzrdzl @thymikee @rasmusprentow

[gantoine]

Code-wise this LGTM, I'll wait to see if the people you pinged will weigh in before merging this.

[vovacodes]

LGTM! thanks for fixing it, it was annoying

[gantoine]

Thanks everyone for contributions and/or feedback!

[jedwards1211]

It correctly handles props.data being null

@ganemone just wanted to point out that void only accepts undefined, not null (not that it's causing me problems in this case)

1: const foo: void = null
                     ^ Cannot assign `null` to `foo` because null [1] is incompatible with undefined [2].

[jedwards1211]

If Apollo ever ends up getting rid of the empty object behavior, would you guys have any opposition to changing this to just TData | void?

I was using a utility function that normalizes the empty object to undefined, and although I can get rid of that utility function now, in some cases I have to perform more null checks now than I did before, which is slightly annoying.

[jedwards1211]

Wish I had weighed in on this before merge, but my fault that I didn't.
It can get pesky to refactor the following code to add the null checks that are now necessary:

        updateAfterDelete={(cache: DataProxy, {data: rawData}: FetchResult<DestroyDeviceGroupMutationData>) => {
          const data = normalizeData(rawData)
          if (!data) return
          const {destroyDeviceGroup: {deviceGroupId}} = data