Large Flatlist is not rendering all items

Is this a bug report?

This seems to be a bug of the FlatList while trying to render many items (more that 60-70).

Have you read the Contributing Guidelines?

(Write your answer here.)

Environment

We are using macOS and the issue happen on both iphone and android

1. react-native -v: 0.45.1
2. node -v: 6.9.1
3. npm -v: 3.10.8
4. yarn --version:

Then, specify:

• Target Platform: iOS, Android

• Development Operating System: macOS

• Build tools: Xcode, Android Studio

Steps to Reproduce

We are using FlatList to render Message Items and after the Flatlist has been rendered we are using scrollToBottom to go to the last item. The Flatlist is working without any issues when having about 20 items, but when we have many items it is NOT always rendering them and not display them at all. We are having an example with 80 items and sometimes is rendering all of them but most of the times is rendering about 40.

[kuriel-trivu]

For partial shown short list: added those values to FlatList and problem gone:

<FlatList style={{ flex: 0 }}
                    initialNumToRender={data.length}

honestly i don’t know which one fixes the problem or if works for large data.

[simonas88]

I solved the issue by removing flex style property from the container of renderItem. Perhaps this is worth reporting as a separate issue linked specifically with the problematic flex behavior 🤔