fix memo doing the wrong thing

hooks/src/index.js

@@ -61,7 +61,7 @@ options._render = vnode => {
 					hookItem._value = hookItem._nextValue;
 				}
 				hookItem._pendingValue = EMPTY;
-				hookItem._nextValue = hookItem._pendingArgs = undefined;
+				hookItem._pendingArgs = hookItem._nextValue = undefined;
 			});
 		} else {
 			hooks._pendingEffects.forEach(invokeCleanup);
@@ -350,10 +350,9 @@ export function useMemo(factory, args) {
 	/** @type {import('./internal').MemoHookState<T>} */
 	const state = getHookState(currentIndex++, 7);
 	if (argsChanged(state._args, args)) {
-		state._pendingValue = factory();
-		state._pendingArgs = args;
+		state._value = factory();
+		state._args = args;
 		state._factory = factory;
-		return state._pendingValue;
 	}
 
 	return state._value;

hooks/test/browser/combinations.test.js

@@ -477,4 +477,44 @@ describe('combinations', () => {
 			'anchor effect'
 		]);
 	});
+
+	it('should not loop infinitely', () => {
+		const actions = [];
+		let toggle;
+		function App() {
+			const [value, setValue] = useState(false);
+
+			const data = useMemo(() => {
+				actions.push('memo');
+				return {};
+			}, [value]);
+
+			const [prevData, setPreviousData] = useState(data);
+			if (prevData !== data) {
+				setPreviousData(data);
+			}
+
+			actions.push('render');
+			toggle = () => setValue(!value);
+			return <div>Value: {JSON.stringify(value)}</div>;
+		}
+
+		act(() => {
+			render(<App />, scratch);
+		});
+		expect(actions).to.deep.equal(['memo', 'render']);
+		expect(scratch.innerHTML).to.deep.equal('<div>Value: false</div>');
+
+		act(() => {
+			toggle();
+		});
+		expect(actions).to.deep.equal([
+			'memo',
+			'render',
+			'memo',
+			'render',
+			'render'
+		]);
+		expect(scratch.innerHTML).to.deep.equal('<div>Value: true</div>');
+	});
 });

hooks/test/browser/useMemo.test.js

@@ -151,12 +151,13 @@ describe('useMemo', () => {
 		act(() => {
 			set('bye');
 		});
-		expect(calls.length).to.equal(5);
+		expect(calls.length).to.equal(6);
 		expect(calls).to.deep.equal([
 			'doing memo',
 			'render hi',
 			'doing memo',
-			'render bye', // We expect a missing "doing memo"  here because we return to the previous args value
+			'render bye',
+			'doing memo',
 			'render hi'
 		]);
 	});
@@ -172,6 +173,8 @@ describe('useMemo', () => {
 			if (v === 0) {
 				set(v + 1);
 			}
+
+			console.log('hi', res);
 			return <p>{res}</p>;
 		}