chore: speed up exclude_from_object (#12783)

* speed up exclude_from_object

* changeset

* convert prop names to string at compile time

* faster still

---------

Co-authored-by: Rich Harris <rich.harris@vercel.com>

.changeset/brown-insects-float.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+perf: speed up $.exclude_from_object

packages/svelte/src/compiler/utils/ast.js

@@ -276,15 +276,19 @@ function _extract_paths(assignments = [], param, expression, update_expression,
 					const rest_expression = (object) => {
 						/** @type {ESTree.Expression[]} */
 						const props = [];
+
 						for (const p of param.properties) {
 							if (p.type === 'Property' && p.key.type !== 'PrivateIdentifier') {
 								if (p.key.type === 'Identifier' && !p.computed) {
 									props.push(b.literal(p.key.name));
+								} else if (p.key.type === 'Literal') {
+									props.push(b.literal(String(p.key.value)));
 								} else {
-									props.push(p.key);
+									props.push(b.call('String', p.key));
 								}
 							}
 						}
+
 						return b.call('$.exclude_from_object', expression(object), b.array(props));
 					};
 

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

@@ -991,12 +991,16 @@ export function update_pre(signal, d = 1) {
  * @returns {Record<string, unknown>}
  */
 export function exclude_from_object(obj, keys) {
-	obj = { ...obj };
-	let key;
-	for (key of keys) {
-		delete obj[key];
+	/** @type {Record<string, unknown>} */
+	var result = {};
+
+	for (var key in obj) {
+		if (!keys.includes(key)) {
+			result[key] = obj[key];
+		}
 	}
-	return obj;
+
+	return result;
 }
 
 /**

packages/svelte/tests/runtime-legacy/samples/each-block-destructured-object-literal-rest/_config.js

@@ -9,18 +9,21 @@ export default test({
 					quote: 'q1',
 					'wrong-quote': 'wq1',
 					16: '16',
+					17: '17',
 					class: 'class'
 				},
 				{
 					quote: 'q2',
 					'wrong-quote': 'wq2',
 					16: 'sixteen',
+					17: 'seventeen',
 					class: 'glass'
 				},
 				{
 					quote: 'q3',
 					'wrong-quote': 'wq3',
 					16: 'seize',
+					17: 'dix-sept',
 					class: 'mass'
 				}
 			]
@@ -28,19 +31,19 @@ export default test({
 	},
 
 	html: `
-    <p class="class">Quote: q1, Wrong Quote: wq1, 16: 16</p>
-    <p class="glass">Quote: q2, Wrong Quote: wq2, 16: sixteen</p>
-    <p class="mass">Quote: q3, Wrong Quote: wq3, 16: seize</p>
+    <p class="class">Quote: q1, Wrong Quote: wq1, 16: 16, 17: 17</p>
+    <p class="glass">Quote: q2, Wrong Quote: wq2, 16: sixteen, 17: seventeen</p>
+    <p class="mass">Quote: q3, Wrong Quote: wq3, 16: seize, 17: dix-sept</p>
 	`,
 
 	test({ assert, component, target }) {
 		component.objectsArray = [
-			{ quote: 'new-quote', 'wrong-quote': 'wq4', 16: 'ten+six', role: 'role' }
+			{ quote: 'new-quote', 'wrong-quote': 'wq4', 16: 'ten+six', 17: 'ten+seven', role: 'role' }
 		];
 		assert.htmlEqual(
 			target.innerHTML,
 			`
-			<p role="role">Quote: new-quote, Wrong Quote: wq4, 16: ten+six</p>
+			<p role="role">Quote: new-quote, Wrong Quote: wq4, 16: ten+six, 17: ten+seven</p>
 		`
 		);
 	}

packages/svelte/tests/runtime-legacy/samples/each-block-destructured-object-literal-rest/main.svelte

@@ -2,6 +2,6 @@
 	export let objectsArray;
 </script>
 
-{#each objectsArray as { "quote": quotedProp, "wrong-quote": wrongQuote, 16: sixteen, ...props } }
-	<p {...props}>Quote: {quotedProp}, Wrong Quote: {wrongQuote}, 16: {sixteen}</p>
+{#each objectsArray as { "quote": quotedProp, "wrong-quote": wrongQuote, 16: sixteen, [10 + 7]: seventeen, ...props }}
+	<p {...props}>Quote: {quotedProp}, Wrong Quote: {wrongQuote}, 16: {sixteen}, 17: {seventeen}</p>
 {/each}