Caret size is wrong when setting larger font on TextInput

[ospfranco]

Environment

react-native -v: 0.68.3
npm ls react-native-macos: 0.68.34
node -v: 16
npm -v:
yarn --version: 1
xcodebuild -version:

Steps to reproduce the bug

When setting the font size on a text input the text and placeholder get a larger size but the caret remains small:

<TextInput
  autoFocus
  // @ts-expect-error
  enableFocusRing={false}
  value={store.ui.query}
  onChangeText={store.ui.setQuery}
  ref={inputRef}
  style={tw.style(`flex-1 text-lg`)}
  caretHidden
  placeholderTextColor={tw.color('text-gray-400')}
  placeholder={'Search for something...'}
  selectionColor={tw.color('text-accent')}
/>

[ospfranco]

I think this might be the issue:

https://stackoverflow.com/questions/34030024/nstextview-changing-insertion-point-caret-cursor-size-when-there-is-no-string

[ospfranco]

I managed to come up with a kinda working solution. On RCTUITextField.m on the _textDidChange method I overwrite the font again:

- (void)_textDidChange
{
  _textWasPasted = NO;
#if TARGET_OS_OSX // [TODO(macOS GH#774)
  [self setAttributedText:[[NSAttributedString alloc] initWithString:[self text]
                                                          attributes:[self defaultTextAttributes]]];
// TODO this tricks the caret to remain at a constant size, however it still wrong
// When the component mounts the size still wrong
    if([[self text] length] == 0) {
        self.font = [[self defaultTextAttributes] objectForKey:NSFontAttributeName];
    }
#endif // ]TODO(macOS GH#774)
}

[ospfranco]

If I add it to setDefaultTextAttributes it works better:

- (void)setDefaultTextAttributes:(NSDictionary<NSAttributedStringKey, id> *)defaultTextAttributes
{
  if ([_defaultTextAttributes isEqualToDictionary:defaultTextAttributes]) {
    return;
  }
    
  _defaultTextAttributes = defaultTextAttributes;
#if !TARGET_OS_OSX // TODO(macOS GH#774)
  [super setDefaultTextAttributes:defaultTextAttributes];
#endif // TODO(macOS GH#774)
  [self _updatePlaceholder];

#if TARGET_OS_OSX // [TODO(macOS GH#774)
  [self setAttributedText:[[NSAttributedString alloc] initWithString:[self text]
                                                          attributes:[self defaultTextAttributes]]];

    self.font = [[self defaultTextAttributes] objectForKey:NSFontAttributeName]; // Added this!

#endif // ]TODO(macOS GH#774)
}

[Saadnajmi]

Amazing! Would you want to submit a fix?
Textinput is one of the most complex controls across platforms so thank you for working through the layers! From the stack overflow you linked, the fix seems reasonable =)

[ospfranco]

Just with the code I added? I can do that :)

[ospfranco]

@Saadnajmi PR is open