client/my-sites/sidebar/utils.js
function pathStartsWith( fullPath, pathPrefix ) {
	return (
		fullPath === pathPrefix ||
		( fullPath.slice( 0, pathPrefix.length ) === pathPrefix &&
			includes( '/?', fullPath[ pathPrefix.length ] ) )
	);
}
function pathStartsWith( fullPath, pathPrefix ) {
	return (
		fullPath === pathPrefix ||
		( fullPath.slice( 0, pathPrefix.length ) === pathPrefix &&
			includes( '/?', fullPath[ pathPrefix.length ] ) )
	);
}
Check if `path` starts with `pathPrefix` and the very next character (if there is any) is `/` or `?`