i was doing this all wrong

Rich-Harris · Rich-Harris · commit 9dc320581613 · 2024-02-20T09:05:04.000-05:00
diff --git a/packages/svelte/src/internal/client/dev/ownership.js b/packages/svelte/src/internal/client/dev/ownership.js
@@ -1,5 +1,6 @@
 /** @typedef {{ file: string, line: number, column: number }} Location */
 
+import { STATE_SYMBOL } from '../proxy.js';
 import { current_component_context, current_owners, deep_read, untrack } from '../runtime.js';
 
 /** @type {Record<string, Array<{ start: Location, end: Location, component: Function }>>} */
@@ -82,59 +83,45 @@ export function mark_module_end() {
 /** @type {Function | null} */
 let new_owner = null;
 
-/**
- * @param {import('../types.js').SignalDebug} signal
- */
-export function set_owners(signal) {
-	if (current_owners && signal.owners) {
-		for (const owner of current_owners) {
-			signal.owners.add(owner);
-		}
-	}
-}
-
 /**
  *
  * @param {any} object
  * @param {any} owner
  */
 export function add_owner(object, owner) {
 	untrack(() => {
-		new_owner = owner;
-		deep_read(object);
-		new_owner = null;
+		add_owner_to_object(object, owner);
 	});
 }
 
 /**
- * @param {import('../types.js').SignalDebug} signal
+ * @param {any} object
+ * @param {Function} owner
  */
-export function add_owner_to_signal(signal) {
-	if (
-		new_owner &&
-		// @ts-expect-error
-		signal.owners?.has(current_component_context.function)
-	) {
-		signal.owners.add(new_owner);
+function add_owner_to_object(object, owner) {
+	if (object?.[STATE_SYMBOL]?.owners && !object[STATE_SYMBOL].owners.has(owner)) {
+		object[STATE_SYMBOL].owners.add(owner);
+
+		for (const key in object) {
+			add_owner_to_object(object[key], owner);
+		}
 	}
 }
 
 /**
- * @param {import('../types.js').SignalDebug} signal
+ * @param {Set<Function>} owners
  */
-export function check_ownership(signal) {
-	if (!signal.owners) return;
-
+export function check_ownership(owners) {
 	const component = get_component();
 
-	if (component && signal.owners.size > 0 && !signal.owners.has(component)) {
-		let owner = [...signal.owners][0];
+	if (component && !owners.has(component)) {
+		let original = [...owners][0];
 
 		let message =
 			// @ts-expect-error
-			owner.filename !== component.filename
+			original.filename !== component.filename
 				? // @ts-expect-error
-					`${component.filename} mutated a value owned by ${owner.filename}. This is strongly discouraged`
+					`${component.filename} mutated a value owned by ${original.filename}. This is strongly discouraged`
 				: 'Mutating a value outside the component that created it is strongly discouraged';
 
 		// eslint-disable-next-line no-console
diff --git a/packages/svelte/src/internal/client/proxy.js b/packages/svelte/src/internal/client/proxy.js
@@ -10,7 +10,8 @@ import {
 	mutable_source,
 	batch_inspect,
 	set_current_owners,
-	current_owners
+	current_owners,
+	current_component_context
 } from './runtime.js';
 import {
 	array_prototype,
@@ -22,16 +23,18 @@ import {
 	is_frozen,
 	object_prototype
 } from './utils.js';
+import { check_ownership } from './dev/ownership.js';
 
 export const STATE_SYMBOL = Symbol('$state');
 
 /**
  * @template T
  * @param {T} value
  * @param {boolean} [immutable]
+ * @param {Function[]} [owners]
  * @returns {import('./types.js').ProxyStateObject<T> | T}
  */
-export function proxy(value, immutable = true) {
+export function proxy(value, immutable = true, owners) {
 	if (typeof value === 'object' && value != null && !is_frozen(value)) {
 		// If we have an existing proxy, return it...
 		if (STATE_SYMBOL in value) {
@@ -62,7 +65,13 @@ export function proxy(value, immutable = true) {
 
 			if (DEV) {
 				// @ts-expect-error
-				value[STATE_SYMBOL].owner = new Set(current_owners);
+				value[STATE_SYMBOL].owners =
+					owners === undefined
+						? current_component_context
+							? // @ts-expect-error
+								new Set([current_component_context.function])
+							: null
+						: new Set(owners);
 			}
 
 			return proxy;
@@ -136,7 +145,7 @@ const state_proxy_handler = {
 			const metadata = target[STATE_SYMBOL];
 
 			const s = metadata.s.get(prop);
-			if (s !== undefined) set(s, proxy(descriptor.value, metadata.i));
+			if (s !== undefined) set(s, proxy(descriptor.value, metadata.i, metadata.owners));
 		}
 
 		return Reflect.defineProperty(target, prop, descriptor);
@@ -185,7 +194,7 @@ const state_proxy_handler = {
 		) {
 			const previous_owners = current_owners;
 			if (DEV) set_current_owners(metadata.owner);
-			s = (metadata.i ? source : mutable_source)(proxy(target[prop], metadata.i));
+			s = (metadata.i ? source : mutable_source)(proxy(target[prop], metadata.i, metadata.owners));
 			if (DEV) set_current_owners(previous_owners);
 			metadata.s.set(prop, s);
 		}
@@ -228,7 +237,7 @@ const state_proxy_handler = {
 		if (s !== undefined || (effect_active() && (!has || get_descriptor(target, prop)?.writable))) {
 			if (s === undefined) {
 				s = (metadata.i ? source : mutable_source)(
-					has ? proxy(target[prop], metadata.i) : UNINITIALIZED
+					has ? proxy(target[prop], metadata.i, metadata.owners) : UNINITIALIZED
 				);
 				metadata.s.set(prop, s);
 			}
@@ -243,10 +252,18 @@ const state_proxy_handler = {
 	set(target, prop, value) {
 		const metadata = target[STATE_SYMBOL];
 		const s = metadata.s.get(prop);
-		if (s !== undefined) set(s, proxy(value, metadata.i));
+		if (s !== undefined) {
+			set(s, proxy(value, metadata.i, metadata.owners));
+		} else if (DEV) {
+			// TODO transfer ownership, in case it differs
+		}
 		const is_array = metadata.a;
 		const not_has = !(prop in target);
 
+		if (DEV && metadata.owners) {
+			check_ownership(metadata.owners);
+		}
+
 		// variable.length = value -> clear all signals with index >= value
 		if (is_array && prop === 'length') {
 			for (let i = value; i < target.length; i += 1) {
diff --git a/packages/svelte/src/internal/client/runtime.js b/packages/svelte/src/internal/client/runtime.js
@@ -19,7 +19,6 @@ import {
 } from '../../constants.js';
 import { STATE_SYMBOL, unstate } from './proxy.js';
 import { EACH_BLOCK, IF_BLOCK } from './block.js';
-import { add_owner_to_signal, check_ownership, set_owners } from './dev/ownership.js';
 
 export const SOURCE = 1;
 export const DERIVED = 1 << 1;
@@ -183,8 +182,7 @@ function create_source_signal(flags, value) {
 			// value
 			v: value,
 			// this is for DEV only
-			inspect: new Set(),
-			owners: new Set()
+			inspect: new Set()
 		};
 	}
 	return {
@@ -953,8 +951,6 @@ export function get(signal) {
 	if (DEV) {
 		const debuggable = /** @type {import('./types.js').SignalDebug} */ (signal);
 
-		add_owner_to_signal(debuggable);
-
 		// @ts-expect-error
 		if (signal.inspect && inspect_fn) {
 			debuggable.inspect.add(inspect_fn);
@@ -1026,10 +1022,6 @@ export function get(signal) {
  * @returns {V}
  */
 export function set(signal, value) {
-	if (DEV) {
-		check_ownership(/** @type {import('./types.js').SignalDebug} */ (signal));
-	}
-
 	set_signal_value(signal, value);
 	return value;
 }
@@ -1345,10 +1337,6 @@ export function source(initial_value) {
  * @param {import('./types.js').Signal} signal
  */
 function bind_signal_to_component_context(signal) {
-	if (DEV) {
-		set_owners(/** @type {import('./types.js').SignalDebug} */ (signal));
-	}
-
 	if (current_component_context === null || !current_component_context.r) return;
 
 	const signals = current_component_context.d;
diff --git a/packages/svelte/src/internal/client/types.d.ts b/packages/svelte/src/internal/client/types.d.ts
@@ -83,7 +83,7 @@ export type SourceSignalDebug = {
 	/** This is DEV only */
 	inspect: Set<Function>;
 	/** This is DEV only */
-	owners: Set<Function>;
+	proxy?: ProxyStateObject;
 };
 
 export type ComputationSignal<V = unknown> = {
@@ -408,8 +408,8 @@ export interface ProxyMetadata<T = Record<string | symbol, any>> {
 	p: ProxyStateObject<T>;
 	/** The original target this proxy was created for */
 	t: T;
-	/** The component that 'owns' this state, if any */
-	o: string;
+	/** Dev-only — the components that 'own' this state, if any */
+	owners: null | Set<Function>;
 }
 
 export type ProxyStateObject<T = Record<string | symbol, any>> = T & {
