Data Module: Add support for action creators as generators

packages/data/src/index.js

@@ -20,13 +20,15 @@ import isShallowEqual from '@wordpress/is-shallow-equal';
  * Internal dependencies
  */
 import registerDataStore from './store';
+import createStoreRuntime from './runtime';
 
 export { loadAndPersist, withRehydration, withRehydratation } from './persist';
 
 /**
  * Module constants
  */
 const stores = {};
+const runtimes = {};
 const selectors = {};
 const actions = {};
 let listeners = [];
@@ -97,6 +99,9 @@ export function registerReducer( reducerKey, reducer ) {
 		}
 	} );
 
+	// Create the actions runtime
+	runtimes[ reducerKey ] = createStoreRuntime( store );
+
 	return store;
 }
 
@@ -147,6 +152,7 @@ export function registerResolvers( reducerKey, newResolvers ) {
 		}
 
 		const store = stores[ reducerKey ];
+		const runtime = runtimes[ reducerKey ];
 
 		// Normalize resolver shape to object.
 		let resolver = newResolvers[ selectorName ];
@@ -165,20 +171,9 @@ export function registerResolvers( reducerKey, newResolvers ) {
 			// state, it would not be otherwise provided to fulfill.
 			const state = store.getState();
 
-			let fulfillment = resolver.fulfill( state, ...args );
+			const fulfillment = resolver.fulfill( state, ...args );
 
-			// Attempt to normalize fulfillment as async iterable.
-			fulfillment = toAsyncIterable( fulfillment );
-			if ( ! isAsyncIterable( fulfillment ) ) {
-				return;
-			}
-
-			for await ( const maybeAction of fulfillment ) {
-				// Dispatch if it quacks like an action.
-				if ( isActionLike( maybeAction ) ) {
-					store.dispatch( maybeAction );
-				}
-			}
+			await runtime( fulfillment );
 
 			finishResolution( reducerKey, selectorName, args );
 		}
@@ -212,8 +207,8 @@ export function registerResolvers( reducerKey, newResolvers ) {
  * @param {Object} newActions   Actions to register.
  */
 export function registerActions( reducerKey, newActions ) {
-	const store = stores[ reducerKey ];
-	const createBoundAction = ( action ) => ( ...args ) => store.dispatch( action( ...args ) );
+	const runtime = runtimes[ reducerKey ];
+	const createBoundAction = ( action ) => ( ...args ) => runtime( action( ...args ) );
 	actions[ reducerKey ] = mapValues( newActions, createBoundAction );
 }
 
@@ -402,76 +397,4 @@ export const withDispatch = ( mapDispatchToProps ) => createHigherOrderComponent
 	'withDispatch'
 );
 
-/**
- * Returns true if the given argument appears to be a dispatchable action.
- *
- * @param {*} action Object to test.
- *
- * @return {boolean} Whether object is action-like.
- */
-export function isActionLike( action ) {
-	return (
-		!! action &&
-		typeof action.type === 'string'
-	);
-}
-
-/**
- * Returns true if the given object is an async iterable, or false otherwise.
- *
- * @param {*} object Object to test.
- *
- * @return {boolean} Whether object is an async iterable.
- */
-export function isAsyncIterable( object ) {
-	return (
-		!! object &&
-		typeof object[ Symbol.asyncIterator ] === 'function'
-	);
-}
-
-/**
- * Returns true if the given object is iterable, or false otherwise.
- *
- * @param {*} object Object to test.
- *
- * @return {boolean} Whether object is iterable.
- */
-export function isIterable( object ) {
-	return (
-		!! object &&
-		typeof object[ Symbol.iterator ] === 'function'
-	);
-}
-
-/**
- * Normalizes the given object argument to an async iterable, asynchronously
- * yielding on a singular or array of generator yields or promise resolution.
- *
- * @param {*} object Object to normalize.
- *
- * @return {AsyncGenerator} Async iterable actions.
- */
-export function toAsyncIterable( object ) {
-	if ( isAsyncIterable( object ) ) {
-		return object;
-	}
-
-	return ( async function* () {
-		// Normalize as iterable...
-		if ( ! isIterable( object ) ) {
-			object = [ object ];
-		}
-
-		for ( let maybeAction of object ) {
-			// ...of Promises.
-			if ( ! ( maybeAction instanceof Promise ) ) {
-				maybeAction = Promise.resolve( maybeAction );
-			}
-
-			yield await maybeAction;
-		}
-	}() );
-}
-
 registerDataStore();

packages/data/src/runtime.js

@@ -0,0 +1,90 @@
+
+/**
+ * Returns true if the given argument appears to be a dispatchable action.
+ *
+ * @param {*} action Object to test.
+ *
+ * @return {boolean} Whether object is action-like.
+ */
+export function isActionLike( action ) {
+	return (
+		!! action &&
+		typeof action.type === 'string'
+	);
+}
+
+/**
+ * Returns true if the given object is an async iterable, or false otherwise.
+ *
+ * @param {*} object Object to test.
+ *
+ * @return {boolean} Whether object is an async iterable.
+ */
+export function isAsyncIterable( object ) {
+	return (
+		!! object &&
+		typeof object[ Symbol.asyncIterator ] === 'function'
+	);
+}
+
+/**
+ * Returns true if the given object is iterable, or false otherwise.
+ *
+ * @param {*} object Object to test.
+ *
+ * @return {boolean} Whether object is iterable.
+ */
+export function isIterable( object ) {
+	return (
+		!! object &&
+		typeof object[ Symbol.iterator ] === 'function'
+	);
+}
+
+/**
+ * Normalizes the given object argument to an async iterable, asynchronously
+ * yielding on a singular or array of generator yields or promise resolution.
+ *
+ * @param {*} object Object to normalize.
+ *
+ * @return {AsyncGenerator} Async iterable actions.
+ */
+export function toAsyncIterable( object ) {
+	if ( isAsyncIterable( object ) ) {
+		return object;
+	}
+
+	return ( async function* () {
+		// Normalize as iterable...
+		if ( ! isIterable( object ) ) {
+			object = [ object ];
+		}
+
+		for ( let maybeAction of object ) {
+			// ...of Promises.
+			if ( ! ( maybeAction instanceof Promise ) ) {
+				maybeAction = Promise.resolve( maybeAction );
+			}
+
+			yield await maybeAction;
+		}
+	}() );
+}
+
+export default function createStoreRuntime( store ) {
+	return async ( actionCreator ) => {
+		if ( isActionLike( actionCreator ) ) {
+			store.dispatch( actionCreator );
+			return;
+		}
+
+		// Attempt to normalize the action creator as async iterable.
+		actionCreator = toAsyncIterable( actionCreator );
+		for await ( const maybeAction of actionCreator ) {
+			// Dispatch if it quacks like an action.
+			if ( isActionLike( maybeAction ) ) {
+				store.dispatch( maybeAction );
+			}
+		}
+	};
+}

packages/data/src/test/index.js

@@ -23,10 +23,6 @@ import {
 	withSelect,
 	withDispatch,
 	subscribe,
-	isActionLike,
-	isAsyncIterable,
-	isIterable,
-	toAsyncIterable,
 } from '../';
 
 // Mock data store to prevent self-initialization, as it needs to be reset
@@ -751,114 +747,3 @@ describe( 'dispatch', () => {
 		expect( store.getState() ).toBe( 5 );
 	} );
 } );
-
-describe( 'isActionLike', () => {
-	it( 'returns false if non-action-like', () => {
-		expect( isActionLike( undefined ) ).toBe( false );
-		expect( isActionLike( null ) ).toBe( false );
-		expect( isActionLike( [] ) ).toBe( false );
-		expect( isActionLike( {} ) ).toBe( false );
-		expect( isActionLike( 1 ) ).toBe( false );
-		expect( isActionLike( 0 ) ).toBe( false );
-		expect( isActionLike( Infinity ) ).toBe( false );
-		expect( isActionLike( { type: null } ) ).toBe( false );
-	} );
-
-	it( 'returns true if action-like', () => {
-		expect( isActionLike( { type: 'POW' } ) ).toBe( true );
-	} );
-} );
-
-describe( 'isAsyncIterable', () => {
-	it( 'returns false if not async iterable', () => {
-		expect( isAsyncIterable( undefined ) ).toBe( false );
-		expect( isAsyncIterable( null ) ).toBe( false );
-		expect( isAsyncIterable( [] ) ).toBe( false );
-		expect( isAsyncIterable( {} ) ).toBe( false );
-	} );
-
-	it( 'returns true if async iterable', async () => {
-		async function* getAsyncIterable() {
-			yield new Promise( ( resolve ) => process.nextTick( resolve ) );
-		}
-
-		const result = getAsyncIterable();
-
-		expect( isAsyncIterable( result ) ).toBe( true );
-
-		await result;
-	} );
-} );
-
-describe( 'isIterable', () => {
-	it( 'returns false if not iterable', () => {
-		expect( isIterable( undefined ) ).toBe( false );
-		expect( isIterable( null ) ).toBe( false );
-		expect( isIterable( {} ) ).toBe( false );
-		expect( isIterable( Promise.resolve( {} ) ) ).toBe( false );
-	} );
-
-	it( 'returns true if iterable', () => {
-		function* getIterable() {
-			yield 'foo';
-		}
-
-		const result = getIterable();
-
-		expect( isIterable( result ) ).toBe( true );
-		expect( isIterable( [] ) ).toBe( true );
-	} );
-} );
-
-describe( 'toAsyncIterable', () => {
-	it( 'normalizes async iterable', async () => {
-		async function* getAsyncIterable() {
-			yield await Promise.resolve( { ok: true } );
-		}
-
-		const object = getAsyncIterable();
-		const normalized = toAsyncIterable( object );
-
-		expect( ( await normalized.next() ).value ).toEqual( { ok: true } );
-	} );
-
-	it( 'normalizes promise', async () => {
-		const object = Promise.resolve( { ok: true } );
-		const normalized = toAsyncIterable( object );
-
-		expect( ( await normalized.next() ).value ).toEqual( { ok: true } );
-	} );
-
-	it( 'normalizes object', async () => {
-		const object = { ok: true };
-		const normalized = toAsyncIterable( object );
-
-		expect( ( await normalized.next() ).value ).toEqual( { ok: true } );
-	} );
-
-	it( 'normalizes array of promise', async () => {
-		const object = [ Promise.resolve( { ok: true } ) ];
-		const normalized = toAsyncIterable( object );
-
-		expect( ( await normalized.next() ).value ).toEqual( { ok: true } );
-	} );
-
-	it( 'normalizes mixed array', async () => {
-		const object = [ { foo: 'bar' }, Promise.resolve( { ok: true } ) ];
-		const normalized = toAsyncIterable( object );
-
-		expect( ( await normalized.next() ).value ).toEqual( { foo: 'bar' } );
-		expect( ( await normalized.next() ).value ).toEqual( { ok: true } );
-	} );
-
-	it( 'normalizes generator', async () => {
-		function* getIterable() {
-			yield Promise.resolve( { ok: true } );
-		}
-
-		const object = getIterable();
-		const normalized = toAsyncIterable( object );
-
-		expect( ( await normalized.next() ).value ).toEqual( { ok: true } );
-	} );
-} );