improve waterfall detection

Author: Rich-Harris

packages/svelte/src/internal/client/reactivity/deriveds.js

@@ -86,10 +86,11 @@ export function derived(fn) {
 /**
  * @template V
  * @param {() => Promise<V>} fn
+ * @param {boolean} detect_waterfall Whether to print a warning if the value is not read immediately after update
  * @returns {Promise<Source<V>>}
  */
 /*#__NO_SIDE_EFFECTS__*/
-export function async_derived(fn) {
+export function async_derived(fn, detect_waterfall = true) {
 	let parent = /** @type {Effect | null} */ (active_effect);
 
 	if (parent === null) {
@@ -121,7 +122,7 @@ export function async_derived(fn) {
 
 				internal_set(value, v);
 
-				if (DEV) {
+				if (DEV && detect_waterfall) {
 					recent_async_deriveds.add(value);
 
 					setTimeout(() => {

packages/svelte/src/internal/client/reactivity/effects.js

@@ -358,7 +358,7 @@ export function template_effect(fn, sync = [], async = [], d = derived) {
 		var restore = capture();
 		var unsuspend = suspend();
 
-		Promise.all(async.map(async_derived)).then((result) => {
+		Promise.all(async.map((expression) => async_derived(expression, false))).then((result) => {
 			restore();
 
 			if ((effect.f & DESTROYED) !== 0) {