Data: Restore dispatch actions returning actions that are a Promise

packages/data/CHANGELOG.md

@@ -2,7 +2,8 @@
 
 ### Bug Fix
 
-- Restore functionality of action-generators returning a Promise.  Clarify intent and behaviour for `wp.data.dispatch` behaviour ([#14830](https://github.com/WordPress/gutenberg/pull/14830)
+- Restore functionality of action-generators returning a Promise.  Clarify intent and behaviour for `wp.data.dispatch` behaviour. Dispatch actions now always
+ return a promise ([#14830](https://github.com/WordPress/gutenberg/pull/14830)
 
 ## 4.3.0 (2019-03-06)
 

packages/data/src/components/with-dispatch/test/index.js

@@ -34,8 +34,13 @@ describe( 'withDispatch', () => {
 
 			return {
 				increment: () => {
-					const actionReturnedFromDispatch = _dispatch( 'counter' ).increment( count );
-					expect( actionReturnedFromDispatch ).toBe( undefined );
+					const actionReturnedFromDispatch = Promise.resolve( _dispatch( 'counter' ).increment( count ) );
+					expect( actionReturnedFromDispatch ).resolves.toEqual(
+						{
+							type: 'increment',
+							count,
+						}
+					);
 				},
 			};
 		} )( ( props ) => <button onClick={ props.increment } /> );
@@ -120,7 +125,8 @@ describe( 'withDispatch', () => {
 		expect( secondRegistryAction ).toHaveBeenCalledTimes( 2 );
 	} );
 
-	it( 'always calls select with the latest state in the handler passed to the component', () => {
+	it( 'always calls select with the latest state in the handler passed to ' +
+		'the component', () => {
 		const store = registry.registerStore( 'counter', {
 			reducer: ( state = 0, action ) => {
 				if ( action.type === 'update' ) {
@@ -142,8 +148,13 @@ describe( 'withDispatch', () => {
 				update: () => {
 					const innerCount = _select( 'counter' ).getCount();
 					expect( innerCount ).toBe( outerCount );
-					const actionReturnedFromDispatch = _dispatch( 'counter' ).update( innerCount + 1 );
-					expect( actionReturnedFromDispatch ).toBe( undefined );
+					const actionReturnedFromDispatch = Promise.resolve(
+						_dispatch( 'counter' ).update( innerCount + 1 )
+					);
+					expect( actionReturnedFromDispatch ).resolves.toEqual( {
+						type: 'update',
+						count: innerCount + 1,
+					} );
 				},
 			};
 		} )( ( props ) => <button onClick={ props.update } /> );

packages/data/src/namespace-store/index.js

@@ -8,7 +8,6 @@ import {
 	mapValues,
 } from 'lodash';
 import combineReducers from 'turbo-combine-reducers';
-import isPromise from 'is-promise';
 
 /**
  * WordPress dependencies
@@ -189,10 +188,7 @@ function mapSelectors( selectors, store, registry ) {
  */
 function mapActions( actions, store ) {
 	const createBoundAction = ( action ) => ( ...args ) => {
-		const result = store.dispatch( action( ...args ) );
-		if ( isPromise( result ) ) {
-			return result;
-		}
+		return Promise.resolve( store.dispatch( action( ...args ) ) );
 	};
 
 	return mapValues( actions, createBoundAction );

packages/data/src/namespace-store/test/index.js

@@ -110,19 +110,19 @@ describe( 'controls', () => {
 			} );
 		} );
 		it( 'action generator returning a yielded promise control descriptor ' +
-			'resolves as expected', () => {
+			'resolves as expected', async () => {
 			const withPromise = registry.dispatch( 'store' ).withPromise();
-			expect( withPromise ).resolves.toEqual( 10 );
+			await expect( withPromise ).resolves.toEqual( 10 );
 		} );
 		it( 'action generator yielding normal action objects resolves as ' +
-			'expected', () => {
+			'expected', async () => {
 			const withNormal = registry.dispatch( 'store' ).withNormal();
-			expect( withNormal ).resolves.toBeUndefined();
+			await expect( withNormal ).resolves.toBeUndefined();
 		} );
-		it( 'action generator returning a non action like value', () => {
+		it( 'action generator returning a non action like value', async () => {
 			const withNonActionLikeValue = registry.dispatch( 'store' )
 				.withNonActionLikeValue();
-			expect( withNonActionLikeValue ).resolves.toEqual( 10 );
+			await expect( withNonActionLikeValue ).resolves.toEqual( 10 );
 		} );
 		it( 'normal dispatch action throwing error because no action ' +
 			'returned', () => {
@@ -131,8 +131,10 @@ describe( 'controls', () => {
 				'Actions must be plain objects. Use custom middleware for async actions.'
 			);
 		} );
-		it( 'returns undefined for normal dispatch action', () => {
-			expect( registry.dispatch( 'store' ).normal() ).toBeUndefined();
+		it( 'returns action object for normal dispatch action', async () => {
+			await expect( registry.dispatch( 'store' ).normal() )
+				.resolves
+				.toEqual( { type: 'NORMAL' } );
 		} );
 	} );
 	describe( 'action type resolves as expected with just promise ' +
@@ -152,18 +154,23 @@ describe( 'controls', () => {
 				actions,
 			} );
 		} );
-		it( 'normal action returns undefined', () => {
-			expect( registry.dispatch( 'store' ).normal() ).toBeUndefined();
+		it( 'normal action returns action object', async () => {
+			await expect( registry.dispatch( 'store' ).normal() )
+				.resolves
+				.toEqual( { type: 'NORMAL' } );
 		} );
-		it( 'action with promise resolving to action returning undefined', () => {
-			expect( registry.dispatch( 'store' ).withPromiseAndAction() )
+		it( 'action with promise resolving to action returning ' +
+			'action object', async () => {
+			await expect( registry.dispatch( 'store' ).withPromiseAndAction() )
 				.resolves
-				.toBeUndefined();
+				.toEqual( { type: 'WITH_PROMISE' } );
 		} );
-		it( 'action with promise returning non action throws error', () => {
+		it( 'action with promise returning non action throws error', async () => {
 			const dispatchedAction = registry.dispatch( 'store' )
 				.withPromiseAndNonAction();
-			expect( dispatchedAction ).resolves.toBe( 10 );
+			await expect( dispatchedAction ).rejects.toThrow(
+				'Actions must be plain objects. Use custom middleware for async actions.'
+			);
 		} );
 	} );
 } );

packages/data/src/test/registry.js

@@ -541,7 +541,7 @@ describe( 'createRegistry', () => {
 	} );
 
 	describe( 'dispatch', () => {
-		it( 'registers actions to the public API', () => {
+		it( 'registers actions to the public API', async () => {
 			const increment = ( count = 1 ) => ( { type: 'increment', count } );
 			const store = registry.registerStore( 'counter', {
 				reducer: ( state = 0, action ) => {
@@ -554,9 +554,14 @@ describe( 'createRegistry', () => {
 					increment,
 				},
 			} );
-
-			const dispatchResult = registry.dispatch( 'counter' ).increment(); // state = 1
-			expect( dispatchResult ).toBe( undefined ); // Actions are implementation detail.
+			// state = 1
+			const dispatchResult = await registry.dispatch( 'counter' ).increment();
+			await expect( dispatchResult ).toEqual(
+				{
+					type: 'increment',
+					count: 1,
+				}
+			);
 			registry.dispatch( 'counter' ).increment( 4 ); // state = 5
 			expect( store.getState() ).toBe( 5 );
 		} );