Merge branch 'main' into simplify-source-ownership

Author: Rich-Harris

.changeset/new-candles-marry.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+chore: simplify internal component `pop()`

packages/svelte/src/internal/client/context.js

@@ -139,16 +139,14 @@ export function getAllContexts() {
  * @returns {void}
  */
 export function push(props, runes = false, fn) {
-	var ctx = (component_context = {
+	component_context = {
 		p: component_context,
 		c: null,
-		d: false,
 		e: null,
-		m: false,
 		s: props,
 		x: null,
 		l: null
-	});
+	};
 
 	if (legacy_mode_flag && !runes) {
 		component_context.l = {
@@ -159,10 +157,6 @@ export function push(props, runes = false, fn) {
 		};
 	}
 
-	teardown(() => {
-		/** @type {ComponentContext} */ (ctx).d = true;
-	});
-
 	if (DEV) {
 		// component function
 		component_context.function = fn;
@@ -176,37 +170,28 @@ export function push(props, runes = false, fn) {
  * @returns {T}
  */
 export function pop(component) {
-	const context_stack_item = component_context;
-	if (context_stack_item !== null) {
-		if (component !== undefined) {
-			context_stack_item.x = component;
-		}
-		const component_effects = context_stack_item.e;
-		if (component_effects !== null) {
-			var previous_effect = active_effect;
-			var previous_reaction = active_reaction;
-			context_stack_item.e = null;
-			try {
-				for (var i = 0; i < component_effects.length; i++) {
-					var component_effect = component_effects[i];
-					set_active_effect(component_effect.effect);
-					set_active_reaction(component_effect.reaction);
-					create_user_effect(component_effect.fn);
-				}
-			} finally {
-				set_active_effect(previous_effect);
-				set_active_reaction(previous_reaction);
-			}
-		}
-		component_context = context_stack_item.p;
-		if (DEV) {
-			dev_current_component_function = context_stack_item.p?.function ?? null;
+	var context = /** @type {ComponentContext} */ (component_context);
+	var effects = context.e;
+
+	if (effects !== null) {
+		context.e = null;
+
+		for (var fn of effects) {
+			create_user_effect(fn);
 		}
-		context_stack_item.m = true;
 	}
-	// Micro-optimization: Don't set .a above to the empty object
-	// so it can be garbage-collected when the return here is unused
-	return component || /** @type {T} */ ({});
+
+	if (component !== undefined) {
+		context.x = component;
+	}
+
+	component_context = context.p;
+
+	if (DEV) {
+		dev_current_component_function = component_context?.function ?? null;
+	}
+
+	return component ?? /** @type {T} */ ({});
 }
 
 /** @returns {boolean} */

packages/svelte/src/internal/client/dom/elements/transitions.js

@@ -209,21 +209,14 @@ export function transition(flags, element, get_fn, get_params) {
 	var outro;
 
 	function get_options() {
-		var previous_reaction = active_reaction;
-		var previous_effect = active_effect;
-		set_active_reaction(null);
-		set_active_effect(null);
-		try {
+		return without_reactive_context(() => {
 			// If a transition is still ongoing, we use the existing options rather than generating
 			// new ones. This ensures that reversible transitions reverse smoothly, rather than
 			// jumping to a new spot because (for example) a different `duration` was used
 			return (current_options ??= get_fn()(element, get_params?.() ?? /** @type {P} */ ({}), {
 				direction
 			}));
-		} finally {
-			set_active_reaction(previous_reaction);
-			set_active_effect(previous_effect);
-		}
+		});
 	}
 
 	/** @type {TransitionManager} */

packages/svelte/src/internal/client/proxy.js

@@ -8,7 +8,7 @@ import {
 	is_array,
 	object_prototype
 } from '../shared/utils.js';
-import { state as source, set } from './reactivity/sources.js';
+import { state as source, set, increment } from './reactivity/sources.js';
 import { PROXY_PATH_SYMBOL, STATE_SYMBOL } from '#client/constants';
 import { UNINITIALIZED } from '../../constants.js';
 import * as e from './errors.js';
@@ -118,7 +118,7 @@ export function proxy(value) {
 				if (prop in target) {
 					const s = with_parent(() => source(UNINITIALIZED, stack));
 					sources.set(prop, s);
-					update_version(version);
+					increment(version);
 
 					if (DEV) {
 						tag(s, get_label(path, prop));
@@ -136,7 +136,7 @@ export function proxy(value) {
 					}
 				}
 				set(s, UNINITIALIZED);
-				update_version(version);
+				increment(version);
 			}
 
 			return true;
@@ -304,7 +304,7 @@ export function proxy(value) {
 					}
 				}
 
-				update_version(version);
+				increment(version);
 			}
 
 			return true;
@@ -343,14 +343,6 @@ function get_label(path, prop) {
 	return /^\d+$/.test(prop) ? `${path}[${prop}]` : `${path}['${prop}']`;
 }
 
-/**
- * @param {Source<number>} signal
- * @param {1 | -1} [d]
- */
-function update_version(signal, d = 1) {
-	set(signal, signal.v + d);
-}
-
 /**
  * @param {any} value
  */

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

@@ -179,28 +179,18 @@ export function teardown(fn) {
 export function user_effect(fn) {
 	validate_effect('$effect');
 
-	// Non-nested `$effect(...)` in a component should be deferred
-	// until the component is mounted
-	var defer =
-		active_effect !== null &&
-		(active_effect.f & BRANCH_EFFECT) !== 0 &&
-		component_context !== null &&
-		!component_context.m;
-
 	if (DEV) {
 		define_property(fn, 'name', {
 			value: '$effect'
 		});
 	}
 
-	if (defer) {
+	if (!active_reaction && active_effect && (active_effect.f & BRANCH_EFFECT) !== 0) {
+		// Top-level `$effect(...)` in a component — defer until mount
 		var context = /** @type {ComponentContext} */ (component_context);
-		(context.e ??= []).push({
-			fn,
-			effect: active_effect,
-			reaction: active_reaction
-		});
+		(context.e ??= []).push(fn);
 	} else {
+		// Everything else — create immediately
 		return create_user_effect(fn);
 	}
 }

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

@@ -268,14 +268,6 @@ export function spread_props(...props) {
 	return new Proxy({ props }, spread_props_handler);
 }
 
-/**
- * @param {Derived} current_value
- * @returns {boolean}
- */
-function has_destroyed_component_ctx(current_value) {
-	return current_value.ctx?.d ?? false;
-}
-
 /**
  * This function is responsible for synchronizing a possibly bound prop with the inner component state.
  * It is used whenever the compiler sees that the component writes to the prop, or when it has a default prop_value.

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

@@ -259,6 +259,14 @@ export function update_pre(source, d = 1) {
 	return set(source, d === 1 ? ++value : --value);
 }
 
+/**
+ * Silently (without using `get`) increment a source
+ * @param {Source<number>} source
+ */
+export function increment(source) {
+	set(source, source.v + 1);
+}
+
 /**
  * @param {Value} signal
  * @param {number} status should be DIRTY or MAYBE_DIRTY

packages/svelte/src/internal/client/types.d.ts

@@ -14,16 +14,8 @@ export type ComponentContext = {
 	p: null | ComponentContext;
 	/** context */
 	c: null | Map<unknown, unknown>;
-	/** destroyed */
-	d: boolean;
 	/** deferred effects */
-	e: null | Array<{
-		fn: () => void | (() => void);
-		effect: null | Effect;
-		reaction: null | Reaction;
-	}>;
-	/** mounted */
-	m: boolean;
+	e: null | Array<() => void | (() => void)>;
 	/**
 	 * props — needed for legacy mode lifecycle functions, and for `createEventDispatcher`
 	 * @deprecated remove in 6.0

packages/svelte/src/reactivity/create-subscriber.js

@@ -1,8 +1,7 @@
 import { get, tick, untrack } from '../internal/client/runtime.js';
 import { effect_tracking, render_effect } from '../internal/client/reactivity/effects.js';
-import { source } from '../internal/client/reactivity/sources.js';
+import { source, increment } from '../internal/client/reactivity/sources.js';
 import { tag } from '../internal/client/dev/tracing.js';
-import { increment } from './utils.js';
 import { DEV } from 'esm-env';
 
 /**

packages/svelte/src/reactivity/map.js

@@ -1,9 +1,8 @@
 /** @import { Source } from '#client' */
 import { DEV } from 'esm-env';
-import { set, source, state } from '../internal/client/reactivity/sources.js';
+import { set, source, state, increment } from '../internal/client/reactivity/sources.js';
 import { label, tag } from '../internal/client/dev/tracing.js';
 import { get, update_version } from '../internal/client/runtime.js';
-import { increment } from './utils.js';
 
 /**
  * A reactive version of the built-in [`Map`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map) object.