サンプル

Verify React 18.2.0 createElement symbol typing, element ref separation, Children traversal and key prefixing, cloneElement, memo, and forwardRef wrappers

sha256:f4fe7fad4e5332e7ba61ae6f9a2f6369fe58bfe63e6f18cd6e988685ff3b4103

MIT-0

実行証拠

宣言された環境と署名済みの実行を分けてあります。このサンプルが何をどこで実行したかをそのまま確認できます。

宣言された環境 linux 24 · ubuntu · glibc 2.39 x64 npm

環境	コントラクト	ステージ	実行日
node 22 · linux alpine/x64 · docker ed25519:c1973797be207ac4	PASS	compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · node-typescript@1node:22-alpine@sha256:c610fcdfb1d5…	2026-08-26

HOW

ゴール: Verify React 18.2.0 createElement symbol typing, element ref separation, Children traversal and key prefixing, cloneElement, memo, and forwardRef wrappers
パッケージ: react 18.2.0
シンボル: React.Children
React.cloneElement
React.createElement
React.forwardRef
React.isValidElement
React.memo
作成日: 2026-08-26T07:45:00Z

React.createElement constructs elements with Symbol.for('react.element') typeof, attaches ref directly to element.ref (leaving props.ref undefined), and places key on element.key.
React.isValidElement validates Symbol.for('react.element') instances and returns false for component functions, memo/forwardRef definitions, plain objects, primitives, and null/undefined.
React.cloneElement shallowly copies and overrides props, replaces or preserves ref/key, coerces key: null to string 'null', and replaces children when trailing arguments are supplied.
React.Children.toArray flattens nested arrays, strips null/undefined/booleans, preserves 0 and empty strings, assigns hierarchical key prefixes, and treats React.Fragment as opaque.
React.Children.count recursively tallies every child slot including null/undefined/booleans, while React.Children.only enforces a single valid React element child and throws on arrays or primitives.
React.Children.map returns null or undefined on null or undefined input, flattens returned arrays, and omits null or undefined mapper return values.
React.memo and React.forwardRef construct wrapper objects with distinctive $$typeof symbols (react.memo, react.forward_ref), custom comparison or render references, and valid element instantiation.

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