Merge pull request woocommerce/woocommerce-admin#1954 from woocommerce/fix/page-page-not-working

getItems: modify parse flag by isUnboundedRequest

plugins/woocommerce-admin/client/wc-api/items/operations.js

@@ -36,16 +36,36 @@ function read( resourceNames, fetch = apiFetch ) {
 		const endpoint = typeEndpointMap[ prefix ];
 		const query = getResourceIdentifier( resourceName );
 		const url = NAMESPACE + `/${ endpoint }${ stringifyQuery( query ) }`;
+		const isUnboundedRequest = -1 === query.per_page;
 
 		try {
 			const response = await fetch( {
-				parse: false,
+				/* eslint-disable max-len */
+				/**
+				 * A false parse flag allows a full response including headers which are useful
+				 * to determine totalCount. However, this invalidates an unbounded request, ie
+				 * `per_page: -1` by skipping middleware in apiFetch.
+				 *
+				 * See the Gutenberg code for more:
+				 * https://github.com/WordPress/gutenberg/blob/dee3dcf49028717b4af3164e3096bfe747c41ed2/packages/api-fetch/src/middlewares/fetch-all-middleware.js#L39-L45
+				 */
+				/* eslint-enable max-len */
+				parse: isUnboundedRequest,
 				path: url,
 			} );
 
-			const items = await response.json();
+			let items;
+			let totalCount;
+
+			if ( isUnboundedRequest ) {
+				items = response;
+				totalCount = items.length;
+			} else {
+				items = await response.json();
+				totalCount = parseInt( response.headers.get( 'x-wp-total' ) );
+			}
+
 			const ids = items.map( item => item.id );
-			const totalCount = parseInt( response.headers.get( 'x-wp-total' ) );
 			const itemResources = items.reduce( ( resources, item ) => {
 				resources[ getResourceName( `${ prefix }-item`, item.id ) ] = { data: item };
 				return resources;