7.4.0-rc.0 flow imported type intersection error - Cannot read property 'length' of undefined in prop-types.js #1413
Comments
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It appears to happen when there is an intersection of an imported type: import type { HiddenProps } from './types';
type DefaultProps = {
classes: Object,
};
export type Props = HiddenProps & {
classes?: Object,
};
function HiddenCss(props: DefaultProps & Props) {
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rosskevin
changed the title
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Thanks for looking into this. I guess it is related to: #1404 where we added support for the IntersectionTypeAnnotation. I can fix the crash easily, but can we even properly validate the props in this case? Since they are imported from another file, we do not what's inside them... 😞 |
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I did a quick check and there were 2 issues:
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@rosskevin @bsr203 can you check out https://github.com/jseminck/eslint-plugin-react/tree/intersection-imported-type and see if it fixes the issue for you? I've added test cases that cover the examples here. @rosskevin did the issue appear in the material-ui code base? Yesterday I was looking around for open-source code bases that we could use to test releases. Perhaps it's a good candidate? My other ideas so far were https://codesandbox.io/ & https://babeljs.io/repl/ 😄 |
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I tested on material-ui with this branch and found another problem with the I think it's the following case: export type Props = HiddenProps & {
/**
* Useful to extend the style applied to components.
*/
classes?: Object,
}; |
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hi @yannickcr I get a different stack this time. |
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@bsr203 see my last comment. I just pushed a fix to my branch and tested it on the material-ui project and now everything passes 🎉 I still have to clean up the code though... it's a bit messy. To try it out (or |
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@jseminck everything looks good for me. no crash and also props are being detected. thanks again for the quick fix and help. |
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Thanks everyone for the assistance. Regarding importing from other files, it is possible. I did some research into the matter and commented my findings here: brigand/babel-plugin-flow-react-proptypes#106 (comment) Essentially, this is a common problem and |
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Cool. Thanks for testing @bsr203. I'll clean up the code and push the changes. It'll take a bit of time as I have some things to attend to. Regarding imports from other files: For now I'll stick to the same logic as we applied previously: if there's an import of a type, then we cannot find it, and we just skip props validation for that file. I'll try to read through that thread later and see how complicated it is 😄 |
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@jseminck - if there is a way to extract that code and grab imported types, it might be a generally useful utility project. I know the And yes, the callemall/material-ui#v1-beta is a perfect project for smoke testing! |
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Closely related to this issue I'm also seeing the following code: type SomeType = {};
type SomeOtherType = {
a: number
} & SomeType;Result in the following |
We are heavy flow users and are on flow 0.54.0, so I assume this may be related to @jseminck's changes in #1400. This may be an entirely new case or separate bug.
It appears to be failing when visiting
IntersectionTypeAnnotation:How can I help narrow this down further?
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