microsoft / microsoft/react-native-windows

JS integer literals are parsed into folly::dynamic ints on debug, doubles on release

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Area: Native Modules bug Workstream: Component Parity
Dominant language
C++
Stars
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Forks
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Avg merge
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Merged PRs (30d)
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Description

This bug was found while writing the Camera Native Module.
For example: Method TakePicture() below:
REACT_METHOD(takePicture)
void takePicture(
std::map<std::wstring, winrt::Microsoft::ReactNative::JSValue>&& options,
int viewTag,
winrt::Microsoft::ReactNative::ReactPromise&& result) noexcept);

Options can contain a value pair such as {"target", 2}, when parsing the JSValue, 2 is Int64 in debug build but Double in Release build. I have to write a utility function to parse both types as a workaround.

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First steps

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  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by tracing the JSValue conversion used by REACT_METHOD(takePicture) for {"target", 2}, comparing debug and release behavior around folly::dynamic. Done means integer literals produce the same value type in both builds; add or run coverage for this example if the existing test path is found.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp, react-native
Domain
mobile-dev
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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