From 88582479f2d4bae08d055585a4ef2256e599e107 Mon Sep 17 00:00:00 2001
From: Dominic Gannaway <trueadm@users.noreply.github.com>
Date: Sat, 20 Jan 2024 16:03:52 +0000
Subject: [PATCH] chore: improve should_proxy_or_freeze logic internally
 (#10249)

---
 .changeset/angry-plums-punch.md               |  5 +++
 .../phases/3-transform/client/utils.js        | 32 +++++++++++++++----
 .../client/visitors/javascript-runes.js       |  9 ++++--
 3 files changed, 36 insertions(+), 10 deletions(-)
 create mode 100644 .changeset/angry-plums-punch.md

diff --git a/.changeset/angry-plums-punch.md b/.changeset/angry-plums-punch.md
new file mode 100644
index 0000000000..22af9d313b
--- /dev/null
+++ b/.changeset/angry-plums-punch.md
@@ -0,0 +1,5 @@
+---
+"svelte": patch
+---
+
+chore: improve should_proxy_or_freeze logic internally
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/utils.js b/packages/svelte/src/compiler/phases/3-transform/client/utils.js
index c5ff3866d1..49ca618ada 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/utils.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/utils.js
@@ -293,7 +293,7 @@ export function serialize_set_binding(node, context, fallback, options) {
 					if (
 						context.state.analysis.runes &&
 						!options?.skip_proxy_and_freeze &&
-						should_proxy_or_freeze(value)
+						should_proxy_or_freeze(value, context.state.scope)
 					) {
 						const assignment = fallback();
 						if (assignment.type === 'AssignmentExpression') {
@@ -310,7 +310,7 @@ export function serialize_set_binding(node, context, fallback, options) {
 						left,
 						context.state.analysis.runes &&
 							!options?.skip_proxy_and_freeze &&
-							should_proxy_or_freeze(value)
+							should_proxy_or_freeze(value, context.state.scope)
 							? private_state.kind === 'frozen_state'
 								? b.call('$.freeze', value)
 								: b.call('$.proxy', value)
@@ -330,7 +330,7 @@ export function serialize_set_binding(node, context, fallback, options) {
 				context.state.analysis.runes &&
 				public_state !== undefined &&
 				!options?.skip_proxy_and_freeze &&
-				should_proxy_or_freeze(value)
+				should_proxy_or_freeze(value, context.state.scope)
 			) {
 				const assignment = fallback();
 				if (assignment.type === 'AssignmentExpression') {
@@ -398,7 +398,7 @@ export function serialize_set_binding(node, context, fallback, options) {
 					b.id(left_name),
 					context.state.analysis.runes &&
 						!options?.skip_proxy_and_freeze &&
-						should_proxy_or_freeze(value)
+						should_proxy_or_freeze(value, context.state.scope)
 						? b.call('$.proxy', value)
 						: value
 				);
@@ -408,7 +408,7 @@ export function serialize_set_binding(node, context, fallback, options) {
 					b.id(left_name),
 					context.state.analysis.runes &&
 						!options?.skip_proxy_and_freeze &&
-						should_proxy_or_freeze(value)
+						should_proxy_or_freeze(value, context.state.scope)
 						? b.call('$.freeze', value)
 						: value
 				);
@@ -623,8 +623,11 @@ export function get_prop_source(binding, state, name, initial) {
 	return b.call('$.prop', ...args);
 }
 
-/** @param {import('estree').Expression} node */
-export function should_proxy_or_freeze(node) {
+/**
+ * @param {import('estree').Expression} node
+ * @param {import("../../scope.js").Scope | null} scope
+ */
+export function should_proxy_or_freeze(node, scope) {
 	if (
 		!node ||
 		node.type === 'Literal' ||
@@ -637,5 +640,20 @@ export function should_proxy_or_freeze(node) {
 	) {
 		return false;
 	}
+	if (node.type === 'Identifier' && scope !== null) {
+		const binding = scope.get(node.name);
+		// Let's see if the reference is something that can be proxied or frozen
+		if (
+			binding !== null &&
+			!binding.reassigned &&
+			binding.initial !== null &&
+			binding.initial.type !== 'FunctionDeclaration' &&
+			binding.initial.type !== 'ClassDeclaration' &&
+			binding.initial.type !== 'ImportDeclaration' &&
+			binding.initial.type !== 'EachBlock'
+		) {
+			return should_proxy_or_freeze(binding.initial, null);
+		}
+	}
 	return true;
 }
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/visitors/javascript-runes.js b/packages/svelte/src/compiler/phases/3-transform/client/visitors/javascript-runes.js
index 0150c30293..f4fc46ce81 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/visitors/javascript-runes.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/visitors/javascript-runes.js
@@ -85,11 +85,14 @@ export const javascript_visitors_runes = {
 
 						value =
 							field.kind === 'state'
-								? b.call('$.source', should_proxy_or_freeze(init) ? b.call('$.proxy', init) : init)
+								? b.call(
+										'$.source',
+										should_proxy_or_freeze(init, state.scope) ? b.call('$.proxy', init) : init
+									)
 								: field.kind === 'frozen_state'
 									? b.call(
 											'$.source',
-											should_proxy_or_freeze(init) ? b.call('$.freeze', init) : init
+											should_proxy_or_freeze(init, state.scope) ? b.call('$.freeze', init) : init
 										)
 									: b.call('$.derived', b.thunk(init));
 					} else {
@@ -238,7 +241,7 @@ export const javascript_visitors_runes = {
 				 */
 				const create_state_declarator = (id, value) => {
 					const binding = /** @type {import('#compiler').Binding} */ (state.scope.get(id.name));
-					if (should_proxy_or_freeze(value)) {
+					if (should_proxy_or_freeze(value, state.scope)) {
 						value = b.call(rune === '$state' ? '$.proxy' : '$.freeze', value);
 					}
 					if (is_state_source(binding, state)) {