flow not checking propTypes for newly created "react-native init" project

[tomduncalf]

Setup: OS X El Capitan, Flow: 0.26, react-native-cli: 1.0.0, react-native: 0.23.1, Atom: 1.8.0, Nuclide: 0.146.0

It seems that flow is not properly checking propTypes of react-native components for a new project created with react-native init.

If I modify index.ios.js to have an invalid property on one of the components, for example:

<View style={styles.container} accessible='123'>

(where accessible should be PropTypes.bool), I get no error either in Nuclide or when running flow. I also get no autocompletion of props in Nuclide.

flow is doing something, however, as if I write a plain function e.g. function test(a: string) and try and call it with the wrong type e.g. test(3), I do get an error in both flow and Nuclide.

I have the same problem with this starter kit repo: https://github.com/jhabdas/react-native-webpack-starter-kit but interestingly, not with the F8App from https://github.com/fbsamples/f8app – with the later, autocomplete and propType checking acts like I would expect it to.

[dleen]

I get the same issue when importing View from the usual location:
import { View } from 'react-native';

No error is shown when making the same type error as described in the issue above. However when importing directly from the file node_modules/react-native/Libraries/Components/View/View.js i.e.

import View from 'react-native/Libraries/Components/View/View'

I get the correct error:

src/components/Home.js:22
 22:   <View style={styles.container} accessible='123'>
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ React element `View`
 22:   <View style={styles.container} accessible='123'>
                                                 ^^^^^ string. This type is incompatible with
109:     accessible: PropTypes.bool,
                     ^^^^^^^^^^^^^^ boolean. See: node_modules/react-native/Libraries/Components/View/View.js:109

So something is getting list along the way. I'll try take a deeper look.

[tomduncalf]

Ah, nice find. I wonder if the culprit could be https://github.com/facebook/react-native/blob/master/Libraries/react-native/react-native.js#L9 – the way the modules are exported is using getters, which that line says Flow doesn't support, so I wonder if that is disabling Flow for anything that is required from the main entry point rather than directly?

[mkonicek]

Hi there! This issue is being closed because it has been inactive for a while.

But don't worry, it will live on with ProductPains! Check out its new home: https://productpains.com/post/react-native/flow-not-checking-proptypes-for-newly-created-react-native-init-project

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