src/vs/platform/files/browser/htmlFileSystemProvider.ts/HTMLFileSystemProvider/getDirectoryHandle
class HTMLFileSystemProvider:	private async getDirectoryHandle(resource: URI): Promise<FileSystemDirectoryHandle | undefined> {
		const handle = await this.doGetHandle(resource);
		if (handle instanceof FileSystemDirectoryHandle) {
			return handle;
		}

		const parentUri = this.extUri.dirname(resource);
		if (this.extUri.isEqual(parentUri, resource)) {
			return undefined; // return when root is reached to prevent infinite recursion
		}

		const parent = await this.getDirectoryHandle(parentUri);

		try {
			return await parent?.getDirectoryHandle(extUri.basename(resource));
		} catch (error) {
			return undefined; // guard against possible DOMException
		}
	}