meliorence / meliorence/react-native-snap-carousel
useRef with TypeScript
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Description
Is this a bug report, a feature request, or a question?
Bug report.
Have you followed the required steps before opening a bug report?
- I have read the guidelines regarding bug report.
- I have reviewed the documentation in its entirety, including the dedicated documentations 📚.
- I have searched for existing issues and made sure that the problem hasn't already been reported.
- I am using the latest plugin version.
- I am following the issue template closely in order to produce a useful bug report.
Have you made sure that it wasn't a React Native bug?
Yes
Is the bug specific to iOS or Android? Or can it be reproduced on both platforms?
TypeScript related.
Is the bug reproductible in a production environment (not a debug one)?
Yes
Environment
info Fetching system and libraries information...
System:
OS: macOS 10.15.5
CPU: (16) x64 AMD Ryzen 7 1700X Eight-Core Processor
Memory: 166.43 MB / 16.00 GB
Shell: 5.7.1 - /bin/zsh
Binaries:
Node: 12.18.0 - ~/.nvm/versions/node/v12.18.0/bin/node
Yarn: 1.22.4 - ~/.nvm/versions/node/v12.18.0/bin/yarn
npm: 6.14.4 - ~/.nvm/versions/node/v12.18.0/bin/npm
SDKs:
iOS SDK:
Platforms: iOS 13.5, DriverKit 19.0, macOS 10.15, tvOS 13.4, watchOS 6.2
IDEs:
Xcode: 11.5/11E608c - /usr/bin/xcodebuild
npmPackages:
react: 16.13.1 => 16.13.1
react-native: https://github.com/expo/react-native/archive/sdk-37.0.0.tar.gz => 0.61.4
Expected Behavior
That TypeScript does not error when using useRef.
Actual Behavior
TypeScript warns that refs are not compatible.
Steps to Reproduce
const carouselRef = useRef<Carousel<Item>>(null)
<Carousel ref={carouselRef} />
Will error:
No overload matches this call.
Overload 1 of 2, '(props: Readonly<CarouselProperties<Item>>): Carousel<Item>', gave the following error.
Type 'MutableRefObject<Carousel<Item>>' is not assignable to type 'string | (string & ((instance: ScrollViewProps) => void)) | (string & RefObject<ScrollViewProps>) | (string & ((instance: CarouselStatic<Item>) => void)) | ... 22 more ... | (RefObject<...> & ... 1 more ... & RefObject<...>)'.
Type 'MutableRefObject<Carousel<Item>>' is not assignable to type 'React.RefObject<...> & React.RefObject<...> & React.RefObject<...>'.
Type 'MutableRefObject<Carousel<Item>>' is not assignable to type 'RefObject<CarouselStatic<Item>>'.
Types of property 'current' are incompatible.
Type 'Carousel<Item>' is missing the following properties from type 'CarouselStatic<Item>': currentIndex, currentScrollPosition, startAutoplay, stopAutoplay, and 4 more.
Overload 2 of 2, '(props: CarouselProperties<Item>, context?: any): Carousel<Item>', gave the following error.
Type 'MutableRefObject<Carousel<Item>>' is not assignable to type 'string | (string & ((instance: ScrollViewProps) => void)) | (string & RefObject<ScrollViewProps>) | (string & ((instance: CarouselStatic<Item>) => void)) | ... 22 more ... | (RefObject<...> & ... 1 more ... & RefObject<...>)'.
Type 'MutableRefObject<Carousel<Item>>' is not assignable to type 'React.RefObject<...> & React.RefObject<...> & React.RefObject<...>'.
Type 'MutableRefObject<Carousel<Item>>' is not assignable to type 'RefObject<CarouselStatic<Item>>'.
I also tried typing the useRef with CarouselStatic but this didn't help.
I see that I can also do:
<Carousel ref={(ref) => (carouselRef.current = ref)} />
Although I am not sure the typings are correct?
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by reproducing the useRef snippet from the issue against the package's TypeScript declarations, then inspect the Carousel ref typing implicated by the compiler error. Done means a correctly typed useRef can be passed to Carousel without the reported overload or ref incompatibility errors.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- react-native, typescript
- Domain
- mobile-dev
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100