Insert new recommendations at the correct position

client/state/reader/start/reducer.js

@@ -54,19 +54,26 @@ export function items( state = [], action ) {
 			const totalRecommendationsCount = state.length + newRecommendations.length;
 
 			forEach( newRecommendations, ( recommendation ) => {
-				// We want to insert the new recommendation immediately after its parent, if there is one
+				// Find the parent recommendation, if there is one.
 				let parentPosition = findIndex( state, ( item ) => {
 					if ( ! has( item, 'recommended_site_ID' ) ) {
 						return false;
 					}
 					return item.recommended_site_ID === recommendation.origin_site_ID && item.recommended_post_ID === recommendation.origin_post_ID;
 				} );
 
-				if ( parentPosition < 0 ) {
-					parentPosition = totalRecommendationsCount - 1;
+				let childPosition;
+				if ( parentPosition >= 0 ) {
+					// Insert the new recommendation immediately after the parent, if we found one.
+					childPosition = parentPosition + 1;
+				} else {
+					// No parent recommendation? Insert it at the end.
+					childPosition = totalRecommendationsCount - 1;
 				}
 
-				updatedRecommendations = insertItemAtArrayPosition( updatedRecommendations, recommendation, parentPosition );
+				debug( 'Inserting recommendation ID ' + recommendation.ID + ' at position ' + childPosition );
+
+				updatedRecommendations = insertItemAtArrayPosition( updatedRecommendations, recommendation, childPosition );
 			} );
 			return updatedRecommendations;
 

client/state/reader/start/test/reducer.js

@@ -53,7 +53,7 @@ describe( 'reducer', () => {
 				type: READER_START_RECOMMENDATIONS_RECEIVE,
 				recommendations: [ newRecommendation ]
 			} );
-			expect( state[1] ).to.eql( newRecommendation );
+			expect( state[2] ).to.eql( newRecommendation );
 		} );
 	} );
 } );