onTextLayout incorrectly returns multiple lines for text that renders in a single line
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Descripción
Description
onTextLayout is returning incorrect lines data for simple single-line text.
In previous React Native versions (tested on Expo 52 with react-native 0.79), the lines array matched the actual number of rendered lines. After the latest update (RN 0.81), some texts that clearly render in one line are reported as two lines.
This breaks logic that depends on overflow detection (e.g., switching between normal text and marquee scrolling). Because onTextLayout now gives false positives, it’s impossible to reliably detect when text exceeds one line.
Steps to reproduce
The bug is present in Expo template when created with npx create-expo-app@latest.
- Install the dependencies
npm install - Open the app in Expo Go application
- See the log in terminal. You should see the text is rendered in one line, but
onTextLayoutgives an array with 2 items.
React Native Version
0.81.5
Affected Platforms
Runtime - Android
Output of npx @react-native-community/cli info
System:
OS: macOS 26.1
CPU: (11) arm64 Apple M3 Pro
Memory: 286.83 MB / 18.00 GB
Shell:
version: 3.2.57
path: /bin/sh
Binaries:
Node:
version: 22.12.0
path: /Users/smhd/.nvm/versions/node/v22.12.0/bin/node
Yarn: Not Found
npm:
version: 10.9.0
path: /Users/smhd/.nvm/versions/node/v22.12.0/bin/npm
Watchman:
version: 2024.12.02.00
path: /opt/homebrew/bin/watchman
Managers:
CocoaPods: Not Found
SDKs:
iOS SDK:
Platforms:
- DriverKit 24.2
- iOS 18.2
- macOS 15.2
- tvOS 18.2
- visionOS 2.2
- watchOS 11.2
Android SDK: Not Found
IDEs:
Android Studio: 2025.1 AI-251.26094.121.2513.14007798
Xcode:
version: 16.2/16C5032a
path: /usr/bin/xcodebuild
Languages:
Java:
version: 17.0.14
path: /usr/bin/javac
Ruby:
version: 2.6.10
path: /usr/bin/ruby
npmPackages:
"@react-native-community/cli": Not Found
react:
installed: 19.1.0
wanted: 19.1.0
react-native:
installed: 0.81.5
wanted: 0.81.5
react-native-macos: Not Found
npmGlobalPackages:
"*react-native*": Not Found
Android:
hermesEnabled: Not found
newArchEnabled: Not found
iOS:
hermesEnabled: Not found
newArchEnabled: Not found
info React Native v0.82.1 is now available (your project is running on v0.81.5).
info Changelog: https://github.com/facebook/react-native/releases/tag/v0.82.1
info Diff: https://react-native-community.github.io/upgrade-helper/?from=0.81.5&to=0.82.1
info For more info, check out "https://reactnative.dev/docs/upgrading?os=macos".
Stacktrace or Logs
No stacktrace available. Not related in this case.
MANDATORY Reproducer
https://github.com/SMhdAsadi/onTextLayout-issue-rn81
Screenshots and Videos
This is the first page of a new Expo project in default template:
The title "Welcome!" is rendered in one line, but is reported to be in two lines in onTextLayout prop.
Guía de contribución
Primeros pasos
- Lee el issue completo y luego la guía de contribución del proyecto.
- Comenta en el issue que vas a ocuparte — evita que dos personas hagan lo mismo.
- Haz un fork del repositorio y trabaja en una rama.
- Abre un pull request que haga referencia al número del issue.
Línea de trabajo
Ejecuta el reproducer obligatorio en https://github.com/SMhdAsadi/onTextLayout-issue-rn81 con la plantilla de Expo en Android e inspecciona la salida de onTextLayout para el texto de una sola línea “Welcome!”. Traza la ruta de diseño de texto de React Native Android que produce el lines array. Se considera terminado cuando un texto que se renderiza en una línea informa de una línea sin interrumpir la detección de desbordamiento.
Escrito por el modelo de indexación a partir del texto del issue.
Evaluación
- Stack tecnológico
- android, react-native
- Área
- mobile-dev
- Tipo de issue
- Error
- Dificultad
- 3/5
- Tiempo estimado
- 1-2 días
- Estado de actividad
- Tranquilo
- Claridad
- Bastante claro
- Aptitud para principiantes
- 55/100