woocommerce/plugins/woocommerce-admin/client/utils/index.js

/**
 * Get the URL params.
 *
 * @param {string} locationSearch - Querystring part of a URL, including the question mark (?).
 * @return {Object} - URL params.
 */
export function getUrlParams( locationSearch ) {
	if ( locationSearch ) {
		return locationSearch
			.substr( 1 )
			.split( '&' )
			.reduce( ( params, query ) => {
				const chunks = query.split( '=' );
				const key = chunks[ 0 ];
				let value = decodeURIComponent( chunks[ 1 ] );
				value = isNaN( Number( value ) ) ? value : Number( value );
				return ( params[ key ] = value ), params;
			}, {} );
	}
	return {};
}

/**
 * Get the current screen name.
 *
 * @return {string} - Screen name.
 */
export function getScreenName() {
	let screenName = '';
	const { page, path, post_type: postType } = getUrlParams(
		window.location.search
	);
	if ( page ) {
		const currentPage = page === 'wc-admin' ? 'home_screen' : page;
		screenName = path
			? path.replace( /\//g, '_' ).substring( 1 )
			: currentPage;
	} else if ( postType ) {
		screenName = postType;
	}
	return screenName;
}

/**
 * Similar to filter, but return two arrays separated by a partitioner function
 *
 * @param {Array} arr - Original array of values.
 * @param {Function} partitioner - Function to return truthy/falsy values to separate items in array.
 *
 * @return {Array} - Array of two arrays, first including truthy values, and second including falsy.
 */
export const sift = ( arr, partitioner ) =>
	arr.reduce(
		( all, curr ) => {
			all[ !! partitioner( curr ) ? 0 : 1 ].push( curr );
			return all;
		},
		[ [], [] ]
	);