Hacktoberfest 2026：メンテナが10月に向けて印を付けた、オープンで初心者向けの issue。 Hacktoberfest の issue を見る

Babel plugin: an undefined `onLongPress` becomes a function, so `Pressable` drops `onPress` after a long press

オープン
  • 何か問題がありますか？
#1,509 コメント 1 件 リアクション 0 件 担当者 1 名 GitHub で見る

メンテナーはふだん 1 日以内に返信

@cdn34dd がすでに取り組んでいます。

2026年10月22日 から。

評価

難易度
2/5
見積もり時間
1〜3時間
初心者へのやさしさ
25/100
issue の種類
バグ
明瞭さ
明確に書かれている
活発さ
活発
技術スタック
javascript, react-native, typescript
領域
backend, mobile

調査の方向性

The issue identifies generated Babel output and the handler transformation in the React Native Babel plugin, but gives no source file or test path. Start by locating the transformation that wraps handlers passed by reference and the tests covering its generated output. Done means an undefined handler remains undefined and the regression is covered; the reporter says they already have a fix ready and plan to open a PR.

索引モデルが issue の本文から書いたものです。

説明

bug
Describe the bug

When a tracked handler is passed by reference and its value is undefined at runtime (for example an optional prop), the babel plugin still replaces it with a wrapper function. The component therefore always receives a defined handler.

For Pressable this changes behavior. React Native's Pressability skips onPress on release when onLongPress != null and the press was held longer than delayLongPress (500ms by default). Because the plugin wraps onLongPress even when it is undefined, every press held for more than 500ms no longer calls onPress, even though the app never set a long-press handler.

This is related to #1226. The fix for it (#1243, released in 3.3.0) added optional chaining (onLongPress?.(...args)), which stops the crash, but the prop itself is still always a function.

Generated output (3.5.0, unchanged in 3.11.0 and on develop):

onLongPress: (...args) => {
  if (DdBabelInteractionTracking.getInstance()) return DdBabelInteractionTracking.getInstance().wrapRumAction(onLongPress, "TAP", { /* ... */ })(...args);
  else return onLongPress?.(...args);
}
Reproduction steps
import { Pressable, Text } from 'react-native';

const Button = ({ onPress, onLongPress }: { onPress: () => void; onLongPress?: () => void }) => (
  <Pressable onPress={onPress} onLongPress={onLongPress}>
    <Text>Press me</Text>
  </Pressable>
);

// Usage: no onLongPress is passed
<Button onPress={() => console.log('pressed')} />
  1. Enable @datadog/mobile-react-native-babel-plugin in babel.config.js.
  2. Tap the button: pressed is logged.
  3. Press and hold the button for more than 500ms, then release: nothing is logged.
  4. Remove the babel plugin (or pass {...(onLongPress ? { onLongPress } : {})} instead of onLongPress={onLongPress}): the long press logs pressed again.
SDK logs

N/A (no error is thrown; onPress is silently not called).

Expected behavior

A handler that is undefined at runtime stays undefined, so the component behaves the same with and without the plugin. For example:

onLongPress: onLongPress != null ? (...args) => { /* RUM wrapper */ } : undefined
Affected SDK versions

@datadog/mobile-react-native-babel-plugin 3.5.0 (also present in 3.11.0 and develop), with @datadog/mobile-react-native 3.9.0

Latest working SDK version

N/A (since the babel plugin started wrapping handlers by reference)

Did you confirm if the latest SDK version fixes the bug?

Yes

Integration Methods

NPM

React Native Version

0.86.3 (New Architecture, Hermes)

Package.json Contents

No response

iOS Setup

No response

Android Setup

No response

Device Information

iOS Simulator, iPhone 17 Pro Max

Other relevant information

Any tracked component that changes behavior based on whether a handler is set is affected the same way (for Pressable, onLongPress is the visible case). I have a fix ready and will open a PR referencing this issue.

主要言語
TypeScript
スター
146
フォーク
67
平均マージ
1日 21時間
マージ済み PR（30日）
19

環境構築

はじめの一歩

  1. issue を最後まで読み、次にプロジェクトのコントリビューションガイドを読みます。
  2. 着手することを issue にコメントします — 二人が同じ作業をするのを防げます。
  3. リポジトリをフォークし、ブランチを切って変更します。
  4. issue 番号を参照したプルリクエストを送ります。

DataDog/dd-sdk-reactnative のほかの issue

DataDog/dd-sdk-reactnative の issue をすべて見る

似ている issue

TypeScript の issue をもっと見る

新しい issue をメールで受け取る

初心者向けの GitHub issue を短くまとめたダイジェスト。