formalise branch effects

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

@@ -7,7 +7,7 @@ import {
 	set_current_effect,
 	set_current_reaction
 } from '../../runtime.js';
-import { block, destroy_effect, pause_effect, render_effect } from '../../reactivity/effects.js';
+import { block, branch, destroy_effect, pause_effect } from '../../reactivity/effects.js';
 import { INERT } from '../../constants.js';
 
 /**
@@ -42,7 +42,7 @@ export function await_block(anchor, get_input, pending_fn, then_fn, catch_fn) {
 		set_current_effect(effect);
 		set_current_reaction(effect); // TODO do we need both?
 		set_current_component_context(component_context);
-		var e = render_effect(() => fn(anchor, value), true);
+		var e = branch(() => fn(anchor, value));
 		set_current_component_context(null);
 		set_current_reaction(null);
 		set_current_effect(null);
@@ -66,7 +66,7 @@ export function await_block(anchor, get_input, pending_fn, then_fn, catch_fn) {
 					destroy_effect(pending_effect);
 				}
 
-				pending_effect = render_effect(() => pending_fn(anchor), true);
+				pending_effect = branch(() => pending_fn(anchor));
 			}
 
 			if (then_effect) pause_effect(then_effect);
@@ -100,7 +100,7 @@ export function await_block(anchor, get_input, pending_fn, then_fn, catch_fn) {
 					destroy_effect(then_effect);
 				}
 
-				then_effect = render_effect(() => then_fn(anchor, input), true);
+				then_effect = branch(() => then_fn(anchor, input));
 			}
 		}
 	});

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

@@ -12,11 +12,11 @@ import { insert, remove } from '../reconciler.js';
 import { untrack } from '../../runtime.js';
 import {
 	block,
+	branch,
 	destroy_effect,
 	effect,
 	pause_effect,
 	pause_effects,
-	render_effect,
 	resume_effect
 } from '../../reactivity/effects.js';
 import { source, mutable_source, set } from '../../reactivity/sources.js';
@@ -153,7 +153,7 @@ function each(anchor, flags, get_collection, get_key, render_fn, fallback_fn, re
 				if (fallback) {
 					resume_effect(fallback);
 				} else {
-					fallback = render_effect(() => {
+					fallback = branch(() => {
 						var dom = fallback_fn(anchor);
 
 						return () => {
@@ -161,7 +161,7 @@ function each(anchor, flags, get_collection, get_key, render_fn, fallback_fn, re
 								remove(dom);
 							}
 						};
-					}, true);
+					});
 				}
 			} else if (fallback !== null) {
 				pause_effect(fallback, () => {
@@ -579,7 +579,7 @@ function create_item(anchor, value, key, index, render_fn, flags) {
 	try {
 		current_each_item = item;
 
-		item.e = render_effect(() => {
+		item.e = branch(() => {
 			var dom = render_fn(anchor, item.v, item.i);
 
 			return () => {
@@ -587,7 +587,7 @@ function create_item(anchor, value, key, index, render_fn, flags) {
 					remove(dom);
 				}
 			};
-		}, true);
+		});
 
 		return item;
 	} finally {

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

@@ -3,9 +3,9 @@ import { hydrate_nodes, hydrating, set_hydrating } from '../hydration.js';
 import { remove } from '../reconciler.js';
 import {
 	block,
+	branch,
 	destroy_effect,
 	pause_effect,
-	render_effect,
 	resume_effect
 } from '../../reactivity/effects.js';
 
@@ -62,7 +62,7 @@ export function if_block(
 			if (consequent_effect) {
 				resume_effect(consequent_effect);
 			} else {
-				consequent_effect = render_effect(() => consequent_fn(anchor), true);
+				consequent_effect = branch(() => consequent_fn(anchor));
 			}
 
 			if (alternate_effect) {
@@ -74,7 +74,7 @@ export function if_block(
 			if (alternate_effect) {
 				resume_effect(alternate_effect);
 			} else if (alternate_fn) {
-				alternate_effect = render_effect(() => alternate_fn(anchor), true);
+				alternate_effect = branch(() => alternate_fn(anchor));
 			}
 
 			if (consequent_effect) {

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

@@ -1,6 +1,6 @@
 import { UNINITIALIZED } from '../../constants.js';
 import { remove } from '../reconciler.js';
-import { block, pause_effect, render_effect } from '../../reactivity/effects.js';
+import { block, branch, pause_effect } from '../../reactivity/effects.js';
 import { safe_not_equal } from '../../reactivity/equality.js';
 
 /**
@@ -33,7 +33,7 @@ export function key_block(anchor, get_key, render_fn) {
 				});
 			}
 
-			effect = render_effect(() => {
+			effect = branch(() => {
 				const dom = render_fn(anchor);
 
 				return () => {
@@ -41,7 +41,7 @@ export function key_block(anchor, get_key, render_fn) {
 						remove(dom);
 					}
 				};
-			}, true);
+			});
 
 			effects.add(effect);
 		}

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

@@ -1,4 +1,4 @@
-import { block, pause_effect, render_effect } from '../../reactivity/effects.js';
+import { block, branch, pause_effect, render_effect } from '../../reactivity/effects.js';
 import { remove } from '../reconciler.js';
 import { current_effect } from '../../runtime.js';
 
@@ -37,7 +37,7 @@ export function component(anchor, get_component, render_fn) {
 		}
 
 		if (component) {
-			effect = render_effect(() => {
+			effect = branch(() => {
 				render_fn(component);
 
 				// `render_fn` doesn't return anything, and we can't reference `effect`
@@ -47,7 +47,7 @@ export function component(anchor, get_component, render_fn) {
 				return () => {
 					if (dom !== null) remove(dom);
 				};
-			}, true);
+			});
 
 			effects.add(effect);
 		}

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

@@ -3,9 +3,9 @@ import { hydrate_anchor, hydrate_nodes, hydrating } from '../hydration.js';
 import { empty } from '../operations.js';
 import {
 	block,
+	branch,
 	destroy_effect,
 	pause_effect,
-	render_effect,
 	resume_effect
 } from '../../reactivity/effects.js';
 import { remove } from '../reconciler.js';
@@ -101,7 +101,7 @@ export function element(anchor, get_tag, is_svg, render_fn) {
 		}
 
 		if (next_tag && next_tag !== current_tag) {
-			effect = render_effect(() => {
+			effect = branch(() => {
 				const prev_element = element;
 				element = hydrating
 					? /** @type {Element} */ (hydrate_nodes[0])
@@ -131,7 +131,7 @@ export function element(anchor, get_tag, is_svg, render_fn) {
 					swap_block_dom(parent_effect, prev_element, element);
 					prev_element.remove();
 				}
-			}, true);
+			});
 		}
 
 		tag = next_tag;

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

@@ -1,6 +1,6 @@
 import { hydrate_anchor, hydrate_nodes, hydrating, set_hydrate_nodes } from '../hydration.js';
 import { empty } from '../operations.js';
-import { block, render_effect } from '../../reactivity/effects.js';
+import { block } from '../../reactivity/effects.js';
 import { remove } from '../reconciler.js';
 
 /**

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

@@ -222,6 +222,11 @@ export function block(fn) {
 	return create_effect(BLOCK_EFFECT, fn, true);
 }
 
+/** @param {(() => void)} fn */
+export function branch(fn) {
+	return create_effect(EFFECT | RENDER_EFFECT | MANAGED, fn, true);
+}
+
 /**
  * @param {import('#client').Effect} effect
  * @returns {void}