iOS: Fixed the bug where a Backspace event was emitted when entering characters after clearing a text in TextInput by an empty string

[hamaron]

The bug #18374 was caused by the loose condition to execute stringByReplacingCharactersInRange in the method textInputShouldChangeTextInRange . As a result, findMismatch wrongly returning true which ends up the Backspace event being fired in another textInputShouldChangeTextInRange call in textInputDidChange.

Test Plan

1. Pass all the tests by yarn run test
2. Run the following code and type any text. (This code is brought from [0.54] [iOS] Wrong 'Backspace' event fired onKeyPress after clearing TextInput #18374. Thank you @michalpetrov!!) And then verify that 'Backspace' events are not emitted after clearing text
   and entering any letters.

type Props = {};
type State = {
  text: string,
  keys: string
};
export default class App extends Component<Props, State> {
  state = {text: '', keys: ''}
  render() {
    return (
      <View style={styles.container}>
        <TextInput style={styles.textInput} value={this.state.text} onChangeText={this.onChangeText} onKeyPress={this.onKeyPress}/>
        <Button title="Clear" onPress={this.onClear}/>
        <Text>Text: {this.state.text}</Text>
        <Text>Keys: {this.state.keys}</Text>
      </View>
    );
  }

  onChangeText = (text: string) => {
    this.setState({text})
  }

  onKeyPress = ({ nativeEvent }: Object) => {
    this.setState({keys: this.state.keys + nativeEvent.key + ', '})
  }

  onClear = () => {
    this.setState({text: '', keys: ''})
  }
}

Related PRs

Release Notes

[IOS] [BUGFIX] [TextInput] - Fixed the bug where Backspace event was emitted when entering a character after clearing a text in TextInput by an empty string

[otusweb]

I tried this fix and it is working correctly in my project

[wack17s]

can this be merged? pls

[facebook-github-bot]

@hamaron I tried to find reviewers for this pull request and wanted to ping them to take another look. However, based on the blame information for the files in this pull request I couldn't find any reviewers. This sometimes happens when the files in the pull request are new or don't exist on master anymore. Is this pull request still relevant? If yes could you please rebase? In case you know who has context on this code feel free to mention them in a comment (one person is fine). Thanks for reading and hope you will continue contributing to the project.

[hamaron]

@facebook-github-bot Yes this is still relevant. Based on the blame info that I can see, the other reviewer should be @shergin. shergin, can you take a look at this PR?

[kayzenkayzen]

Please Merge!

[GStipick]

The fix proposed by @hamaron worked for me as well. The bug that this PR is addressing is vital toward some of our teams code and the ability to update react-native.

[code-jenn-or]

This really needs to be addressed, creates very undesirable behavior in our app

[hamaron]

@facebook-github-bot Rebased the branch on the latest master branch.

[kayzenkayzen]

@hamaron please, fix checks!

[hamaron]

@kayzenkayzen Unfortunately, the tests had been broken when I rebased the branch on master, and the change I made is actually irrelevant to the test failures...

[kayzenkayzen]

@hamaron what does that mean? Is this pull request abandoned? if not, when it usually takes a fix to reach production? Do you know any hack for this issue?

[hamaron]

@kayzenkayzen Thought you wanted me to fix the test failures in CI.
To be clear, I'm not the one who can merge this PR. I need to get this PR reviewed by
one of the core contributors in this repository to get this branch merged.

[hamaron]

@shergin Sorry for bugging you, but it would be great if you could take a look at this bug fix.

[facebook-github-bot]

@hamaron I tried to find reviewers for this pull request and wanted to ping them to take another look. However, based on the blame information for the files in this pull request I couldn't find any reviewers. This sometimes happens when the files in the pull request are new or don't exist on master anymore. Is this pull request still relevant? If yes could you please rebase? In case you know who has context on this code feel free to mention them in a comment (one person is fine). Thanks for reading and hope you will continue contributing to the project.

[Ashoat]

@hamaron: the CI is finally fixed and passing on master. Can you rebase this PR to see the latest CI results?

[hamaron]

@Ashoat OK. I'll rebase the branch shortly.

[atticoos]

@TheSavior we're having a tough time finding a core member to champion the review, would like to tag you in to assist. This should be ready to go

[hamaron]

The branch was rebased and the tests became all green! :)

[elicwhite]

Adding @shergin because it is a text related iOS change.

[Ashoat]

@facebook-github-bot shipit

[facebook-github-bot]

@Ashoat is landing this pull request. If you are a Facebook employee, you can view this diff on Phabricator.

[mtettmar]

Not sure if it's the same bug but I'm seeing the same behaviour in RN 0.72.0 - whatever key is pressed Backspace is also emitted. After upgrading to RN 0.72.0 we were seeing strange behaviour which led me to search and find the report this fix is based on. Have had to use the same workaround with the timestamp.