simplify

packages/svelte/src/internal/client/dom/blocks/each.js

@@ -187,7 +187,7 @@ export function each(node, flags, get_collection, get_key, render_fn, fallback_f
 		}
 	}
 
-	var b = block(() => {
+	block(() => {
 		// store a reference to the effect so that we can update the start/end nodes in reconciliation
 		each_effect ??= /** @type {Effect} */ (active_effect);
 
@@ -310,7 +310,7 @@ export function each(node, flags, get_collection, get_key, render_fn, fallback_f
 					}
 				}
 
-				batch.add_callback(() => b, commit);
+				batch.add_callback(commit);
 			} else {
 				commit();
 			}

packages/svelte/src/internal/client/dom/blocks/if.js

@@ -124,7 +124,7 @@ export function if_block(node, fn, elseif = false) {
 			if (active) batch.skipped_effects.delete(active);
 			if (inactive) batch.skipped_effects.add(inactive);
 
-			batch.add_callback(() => b, commit);
+			batch.add_callback(commit);
 		} else {
 			commit();
 		}
@@ -135,7 +135,7 @@ export function if_block(node, fn, elseif = false) {
 		}
 	};
 
-	var b = block(() => {
+	block(() => {
 		has_branch = false;
 		fn(set_branch);
 		if (!has_branch) {

packages/svelte/src/internal/client/dom/blocks/key.js

@@ -52,7 +52,7 @@ export function key(node, get_key, render_fn) {
 		effect = pending_effect;
 	}
 
-	var b = block(() => {
+	block(() => {
 		if (changed(key, (key = get_key()))) {
 			var target = anchor;
 
@@ -66,7 +66,7 @@ export function key(node, get_key, render_fn) {
 			pending_effect = branch(() => render_fn(target));
 
 			if (defer) {
-				/** @type {Batch} */ (current_batch).add_callback(() => b, commit);
+				/** @type {Batch} */ (current_batch).add_callback(commit);
 			} else {
 				commit();
 			}

packages/svelte/src/internal/client/dom/blocks/svelte-component.js

@@ -51,7 +51,7 @@ export function component(node, get_component, render_fn) {
 		pending_effect = null;
 	}
 
-	var b = block(() => {
+	block(() => {
 		if (component === (component = get_component())) return;
 
 		var defer = should_defer_append();
@@ -70,7 +70,7 @@ export function component(node, get_component, render_fn) {
 		}
 
 		if (defer) {
-			/** @type {Batch} */ (current_batch).add_callback(() => b, commit);
+			/** @type {Batch} */ (current_batch).add_callback(commit);
 		} else {
 			commit();
 		}

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

@@ -97,7 +97,7 @@ export class Batch {
 	 * and append new ones by calling the functions added inside (if/each/key/etc) blocks.
 	 * Key is a function that returns the block effect because #callbacks will be called before
 	 * the block effect reference exists, so we need to capture it in a closure.
-	 * @type {Map<() => Effect, () => void>}
+	 * @type {Map<Effect, () => void>}
 	 */
 	#callbacks = new Map();
 
@@ -229,7 +229,7 @@ export class Batch {
 		// is outstanding from a previous flush, commit
 		if (this.#async_effects.length === 0 && this.#pending === 0) {
 			if (superseded_batches.length > 0) {
-				const own = [...this.#callbacks.keys()].map((c) => c());
+				const own = [...this.#callbacks.keys()];
 				// A superseded batch could have callbacks for e.g. destroying if blocks
 				// that are not part of the current batch because it already happened in the prior one,
 				// and the corresponding block effect therefore returning early because nothing was changed from its
@@ -237,9 +237,9 @@ export class Batch {
 				// We do it from newest to oldest to ensure the correct callback is applied.
 				for (const batch of superseded_batches.reverse()) {
 					for (const [effect, cb] of batch.#callbacks) {
-						if (!own.includes(effect())) {
+						if (!own.includes(effect)) {
 							cb();
-							own.push(effect());
+							own.push(effect);
 						}
 					}
 					batch.remove();
@@ -475,11 +475,10 @@ export class Batch {
 	}
 
 	/**
-	 * @param {() => Effect} effect
 	 * @param {() => void} fn
 	 */
-	add_callback(effect, fn) {
-		this.#callbacks.set(effect, fn);
+	add_callback(fn) {
+		this.#callbacks.set(/** @type {Effect} */ (active_effect), fn);
 	}
 
 	settled() {