Summary:
`getSize` should resolve with an array of `[width, height]` but this mock resolves with `{ width, height }`.
It should be `ReadOnlyArray<number>` instead of `{width: number, height: number}`
The native image loader call is [here](https://github.com/facebook/react-native/blob/main/Libraries/Image/NativeImageLoaderIOS.js#L18):
```js
+getSize: (uri: string) => Promise<$ReadOnlyArray<number>>;
```
but in the [jest setup file](https://github.com/facebook/react-native/blob/main/jest/setup.js):
```js
getSize: jest.fn(url => Promise.resolve({width: 320, height: 240})),
```
My tests were failing on `Image.getSize()` - `TypeError: Invalid attempt to destructure non-iterable instance.`
I managed to trace this down to this object being returned by the Jest mock - looks like it's returning a size object instead of a dimensions array.
## Workaround
If you are hitting this issue, you can work around this mock by using:
```js
ReactNative.NativeModules.ImageLoader.getSize = jest.fn((_) => Promise.resolve([320, 240]));
```
## Changelog
[JavaScript] [Changed]: Changed the mocked return value of `ImageLoader.getSize` to be `[320, 240]` instead of `{ width: 320, height: 240 }`
Pull Request resolved: https://github.com/facebook/react-native/pull/34653
Test Plan: TBD? I think a test with `Image.getSize(path)` will cover it. That's where I hit the error with the ios-specific imageLoader's getSize method.
Reviewed By: robhogan
Differential Revision: D39413522
Pulled By: NickGerleman
fbshipit-source-id: 7f18d7acde0cf94da0b4aec8fe2d0cad3fb0cc55
7be829f2c9