StyleProvider: Convert component to TypeScript (#42541)

* StyleProvider: Convert component to TypeScript

* Update CHANGELOG.md

packages/components/CHANGELOG.md

@@ -42,6 +42,7 @@
 -   `BoxControl`: Refactor away from `_.isEmpty()` ([#42468](https://github.com/WordPress/gutenberg/pull/42468)).
 -   `RadioControl`: Refactor away from `_.isEmpty()` ([#42468](https://github.com/WordPress/gutenberg/pull/42468)).
 -   `SelectControl`: Refactor away from `_.isEmpty()` ([#42468](https://github.com/WordPress/gutenberg/pull/42468)).
+-   `StyleProvider`: Convert to TypeScript ([#42541](https://github.com/WordPress/gutenberg/pull/42541)).
 -   `ComboboxControl`: Replace `keyboardEvent.keyCode` with `keyboardEvent.code`([#42569](https://github.com/WordPress/gutenberg/pull/42569)).
 -   `ComboboxControl`: Add support for uncontrolled mode ([#42752](https://github.com/WordPress/gutenberg/pull/42752)).
 

packages/components/src/style-provider/index.tsx

@@ -0,0 +1,41 @@
+/**
+ * External dependencies
+ */
+import { CacheProvider } from '@emotion/react';
+import createCache from '@emotion/cache';
+import memoize from 'memize';
+import * as uuid from 'uuid';
+
+/**
+ * Internal dependencies
+ */
+import type { StyleProviderProps } from './types';
+
+const uuidCache = new Set();
+
+const memoizedCreateCacheWithContainer = memoize(
+	( container: HTMLElement ) => {
+		// Emotion only accepts alphabetical and hyphenated keys so we just
+		// strip the numbers from the UUID. It _should_ be fine.
+		let key = uuid.v4().replace( /[0-9]/g, '' );
+		while ( uuidCache.has( key ) ) {
+			key = uuid.v4().replace( /[0-9]/g, '' );
+		}
+		uuidCache.add( key );
+		return createCache( { container, key } );
+	}
+);
+
+export function StyleProvider( props: StyleProviderProps ) {
+	const { children, document } = props;
+
+	if ( ! document ) {
+		return null;
+	}
+
+	const cache = memoizedCreateCacheWithContainer( document.head );
+
+	return <CacheProvider value={ cache }>{ children }</CacheProvider>;
+}
+
+export default StyleProvider;

packages/components/src/style-provider/types.ts

@@ -0,0 +1,15 @@
+/**
+ * External dependencies
+ */
+import type { ReactNode } from 'react';
+
+export type StyleProviderProps = {
+	/**
+	 * The children elements.
+	 */
+	children: ReactNode;
+	/**
+	 * Current document.
+	 */
+	document: Document;
+};