react / react/react-native

onTextLayout incorrectly returns multiple lines for text that renders in a single line

Abierto
#54,552 7 comentarios 2 reacciones 0 asignados Ver en GitHub

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Issue: Author Provided Repro Needs: React Native Team Attention
Lenguaje dominante
C++
Estrellas
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Forks
25.3k
Merge medio
1 d 23 h
PR fusionados (30 d)
4

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.

  1. Install the dependencies npm install
  2. Open the app in Expo Go application
  3. See the log in terminal. You should see the text is rendered in one line, but onTextLayout gives 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:

Image

The title "Welcome!" is rendered in one line, but is reported to be in two lines in onTextLayout prop.

Guía de contribución

Abrir la guía de contribución

Primeros pasos

  1. Lee el issue completo y luego la guía de contribución del proyecto.
  2. Comenta en el issue que vas a ocuparte — evita que dos personas hagan lo mismo.
  3. Haz un fork del repositorio y trabaja en una rama.
  4. 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

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