From 1f8f7d7fc614b8e10fd7fc6c04d4cdbb881ef089 Mon Sep 17 00:00:00 2001
From: Andrew Duthie <andrew@andrewduthie.com>
Date: Thu, 4 Apr 2019 15:53:12 -0400
Subject: [PATCH] Data: Return result of middleware chain in resolvers cache
 middleware (#14711)

* Data: Return result of middleware chain in resolvers cache middleware

* Data: Avoid returning result of store.dispatch in public interface
---
 packages/data/src/namespace-store/index.js    |  5 ++-
 .../data/src/namespace-store/test/index.js    | 41 +++++++++++++++++++
 .../data/src/resolvers-cache-middleware.js    |  2 +-
 packages/data/src/test/registry.js            |  3 +-
 4 files changed, 48 insertions(+), 3 deletions(-)

diff --git a/packages/data/src/namespace-store/index.js b/packages/data/src/namespace-store/index.js
index 8a53d28b300c3..3cdbc7a65a348 100644
--- a/packages/data/src/namespace-store/index.js
+++ b/packages/data/src/namespace-store/index.js
@@ -187,7 +187,10 @@ function mapSelectors( selectors, store, registry ) {
  * @return {Object}           Actions mapped to the redux store provided.
  */
 function mapActions( actions, store ) {
-	const createBoundAction = ( action ) => ( ...args ) => store.dispatch( action( ...args ) );
+	const createBoundAction = ( action ) => ( ...args ) => {
+		store.dispatch( action( ...args ) );
+	};
+
 	return mapValues( actions, createBoundAction );
 }
 
diff --git a/packages/data/src/namespace-store/test/index.js b/packages/data/src/namespace-store/test/index.js
index eba9e7e6697fc..a3ee80577ece1 100644
--- a/packages/data/src/namespace-store/test/index.js
+++ b/packages/data/src/namespace-store/test/index.js
@@ -39,4 +39,45 @@ describe( 'controls', () => {
 			expect( action1 ).toBeCalled();
 		} );
 	} );
+
+	it( 'resolves in expected order', ( done ) => {
+		const actions = {
+			wait: () => ( { type: 'WAIT' } ),
+			receive: ( items ) => ( { type: 'RECEIVE', items } ),
+		};
+
+		registry.registerStore( 'store', {
+			reducer: ( state = null, action ) => {
+				if ( action.type === 'RECEIVE' ) {
+					return action.items;
+				}
+
+				return state;
+			},
+			selectors: {
+				getItems: ( state ) => state,
+			},
+			resolvers: {
+				* getItems() {
+					yield actions.wait();
+					yield actions.receive( [ 1, 2, 3 ] );
+				},
+			},
+			controls: {
+				WAIT() {
+					return new Promise( ( resolve ) => process.nextTick( resolve ) );
+				},
+			},
+		} );
+
+		registry.subscribe( () => {
+			const isFinished = registry.select( 'store' ).hasFinishedResolution( 'getItems' );
+			if ( isFinished ) {
+				expect( registry.select( 'store' ).getItems() ).toEqual( [ 1, 2, 3 ] );
+				done();
+			}
+		} );
+
+		registry.select( 'store' ).getItems();
+	} );
 } );
diff --git a/packages/data/src/resolvers-cache-middleware.js b/packages/data/src/resolvers-cache-middleware.js
index 7477b36d805b5..0e661442e180d 100644
--- a/packages/data/src/resolvers-cache-middleware.js
+++ b/packages/data/src/resolvers-cache-middleware.js
@@ -30,7 +30,7 @@ const createResolversCacheMiddleware = ( registry, reducerKey ) => () => ( next
 			registry.dispatch( 'core/data' ).invalidateResolution( reducerKey, selectorName, args );
 		} );
 	} );
-	next( action );
+	return next( action );
 };
 
 export default createResolversCacheMiddleware;
diff --git a/packages/data/src/test/registry.js b/packages/data/src/test/registry.js
index b828cd0199159..e44accd0eab6f 100644
--- a/packages/data/src/test/registry.js
+++ b/packages/data/src/test/registry.js
@@ -555,7 +555,8 @@ describe( 'createRegistry', () => {
 				},
 			} );
 
-			registry.dispatch( 'counter' ).increment(); // state = 1
+			const dispatchResult = registry.dispatch( 'counter' ).increment(); // state = 1
+			expect( dispatchResult ).toBe( undefined ); // Actions are implementation detail.
 			registry.dispatch( 'counter' ).increment( 4 ); // state = 5
 			expect( store.getState() ).toBe( 5 );
 		} );