expose hasResolver property on returned selectors

WordPress · May 5, 2019 · 64e2118 · 64e2118
1 parent 4adbe72
commit 64e2118
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diff --git a/packages/data/CHANGELOG.md b/packages/data/CHANGELOG.md
@@ -4,6 +4,10 @@
 
 - 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)
+
+### Enhancements
+
+- Expose `hasResolver` property on returned selectors indicating whether the selector has a corresponding resolver.
 
 ## 4.3.0 (2019-03-06)
 

diff --git a/packages/data/src/namespace-store/index.js b/packages/data/src/namespace-store/index.js
@@ -213,10 +213,11 @@ function mapResolvers( resolvers, selectors, store ) {
 	const mapSelector = ( selector, selectorName ) => {
 		const resolver = resolvers[ selectorName ];
 		if ( ! resolver ) {
+			selector.hasResolver = false;
 			return selector;
 		}
 
-		return ( ...args ) => {
+		const selectorResolver = ( ...args ) => {
 			async function fulfillSelector() {
 				const state = store.getState();
 				if ( typeof resolver.isFulfilled === 'function' && resolver.isFulfilled( state, ...args ) ) {
@@ -236,6 +237,8 @@ function mapResolvers( resolvers, selectors, store ) {
 			fulfillSelector( ...args );
 			return selector( ...args );
 		};
+		selectorResolver.hasResolver = true;
+		return selectorResolver;
 	};
 
 	return {

diff --git a/packages/data/src/namespace-store/test/index.js b/packages/data/src/namespace-store/test/index.js
@@ -80,6 +80,22 @@ describe( 'controls', () => {
 
 		registry.select( 'store' ).getItems();
 	} );
+	it( 'selectors have expected value for the `hasResolver` property', () => {
+		registry.registerStore( 'store', {
+			reducer: jest.fn(),
+			selectors: {
+				getItems: ( state ) => state,
+				getItem: ( state ) => state,
+			},
+			resolvers: {
+				* getItems() {
+					yield 'foo';
+				},
+			},
+		} );
+		expect( registry.select( 'store' ).getItems.hasResolver ).toBe( true );
+		expect( registry.select( 'store' ).getItem.hasResolver ).toBe( false );
+	} );
 	describe( 'various action types have expected response and resolve as ' +
 		'expected with controls middleware', () => {
 		const actions = {