Merge 38ab820 into 6b5abcb

debug/src/debug.js

@@ -273,7 +273,7 @@ export function initDebug() {
 			let hooks = component.__hooks;
 			if (Array.isArray(hooks._list)) {
 				hooks._list.forEach(hook => {
-					if (hook._callback && (!hook._args || !Array.isArray(hook._args))) {
+					if (hook._factory && (!hook._args || !Array.isArray(hook._args))) {
 						let componentName = getDisplayName(vnode);
 						console.warn(
 							`In ${componentName} you are calling useMemo/useCallback without passing arguments.\n` +

hooks/src/index.d.ts

@@ -106,7 +106,8 @@ export function useCallback<T extends Function>(callback: T, inputs: Inputs): T;
  * This optimization helps to avoid expensive calculations on every render.
  * If no array is provided, a new value will be computed whenever a new function instance is passed as the first argument.
  */
-export function useMemo<T>(factory: () => T, inputs?: Inputs): T;
+// for `inputs`, allow undefined, but don't make it optional as that is very likely a mistake
+export function useMemo<T>(factory: () => T, inputs: Inputs | undefined): T;
 
 /**
  * Returns the current context value, as given by the nearest context provider for the given context.

hooks/src/index.js

@@ -174,16 +174,16 @@ export function useImperativeHandle(ref, createHandle, args) {
 }
 
 /**
- * @param {() => any} callback
+ * @param {() => any} factory
  * @param {any[]} args
  */
-export function useMemo(callback, args) {
+export function useMemo(factory, args) {
 	/** @type {import('./internal').MemoHookState} */
 	const state = getHookState(currentIndex++);
 	if (argsChanged(state._args, args)) {
 		state._args = args;
-		state._callback = callback;
-		return (state._value = callback());
+		state._factory = factory;
+		return (state._value = factory());
 	}
 
 	return state._value;

hooks/src/internal.d.ts

@@ -46,7 +46,7 @@ export interface EffectHookState {
 export interface MemoHookState {
 	_value?: any;
 	_args?: any[];
-	_callback?: () => any;
+	_factory?: () => any;
 }
 
 export interface ReducerHookState {