fix: resolve computed_prop_# collision (#8418)

Fixes #8417

The issue is that unpack_destructuring in each blocks, await blocks, and @const tags were making computed_props independently. This causes computed_props_# to conflict when each blocks were used with @const tags, or await blocks and @const tags, or consecutive @const tags together. Therefore, one solution is to use component.get_unique_name to, well, make unique names and never get conflicts.

src/compiler/compile/nodes/shared/Context.ts

@@ -11,7 +11,7 @@ export type Context = DestructuredVariable | ComputedProperty;
 
 interface ComputedProperty {
 	type: 'ComputedProperty';
-  property_name: string;
+  property_name: Identifier;
   key: Expression | PrivateIdentifier;
 }
  
@@ -30,8 +30,7 @@ export function unpack_destructuring({
 	default_modifier = (node) => node,
 	scope,
 	component,
-	context_rest_properties,
-	number_of_computed_props = { n: 0 }
+	context_rest_properties
 }: {
 	contexts: Context[];
 	node: Node;
@@ -40,10 +39,6 @@ export function unpack_destructuring({
 	scope: TemplateScope;
 	component: Component;
 	context_rest_properties: Map<string, Node>;
-	// we want to pass this by reference, as a sort of global variable, because 
-	// if we pass this by value, we could get computed_property_# variable collisions
-	// when we deal with nested object destructuring
-	number_of_computed_props?: { n: number }; 
 }) {
 	if (!node) return;
 
@@ -72,8 +67,7 @@ export function unpack_destructuring({
 					default_modifier,
 					scope,
 					component,
-					context_rest_properties,
-					number_of_computed_props
+					context_rest_properties
 				});
 				context_rest_properties.set((element.argument as Identifier).name, element);
 			} else if (element && element.type === 'AssignmentPattern') {
@@ -93,8 +87,7 @@ export function unpack_destructuring({
 						)}` as Node,
 					scope,
 					component,
-					context_rest_properties,
-					number_of_computed_props
+					context_rest_properties
 				});
 			} else {
 				unpack_destructuring({
@@ -104,8 +97,7 @@ export function unpack_destructuring({
 					default_modifier,
 					scope,
 					component,
-					context_rest_properties,
-					number_of_computed_props
+					context_rest_properties
 				});
 			}
 		});
@@ -124,8 +116,7 @@ export function unpack_destructuring({
 					default_modifier,
 					scope,
 					component,
-					context_rest_properties,
-					number_of_computed_props
+					context_rest_properties
 				});
 				context_rest_properties.set((property.argument as Identifier).name, property);
 			} else if (property.type === 'Property') {
@@ -136,8 +127,7 @@ export function unpack_destructuring({
 
 				if (property.computed) {
 					// e.g { [computedProperty]: ... }
-					const property_name = `computed_property_${number_of_computed_props.n}`;
-					number_of_computed_props.n += 1;
+					const property_name = component.get_unique_name('computed_property');
 
 					contexts.push({
 						type: 'ComputedProperty',
@@ -178,8 +168,7 @@ export function unpack_destructuring({
 							)}` as Node,
 						scope,
 						component,
-						context_rest_properties,
-						number_of_computed_props
+						context_rest_properties
 					});
 				} else {
 					// e.g. { property } or { property: newName }
@@ -190,8 +179,7 @@ export function unpack_destructuring({
 						default_modifier,
 						scope,
 						component,
-						context_rest_properties,
-						number_of_computed_props
+						context_rest_properties
 					});
 				}
 			}

test/runtime/samples/const-tag-await-then-destructuring-computed-in-computed/_config.js

@@ -0,0 +1,20 @@
+export default {
+	html: `
+		<p>4, 12, 60</p>
+	`,
+
+	async test({ component, target, assert }) {
+		component.permutation = [2, 3, 1];
+		await (component.promise1 = Promise.resolve({length: 1, width: 2, height: 3}));
+		try {
+			await (component.promise2 = Promise.reject({length: 97, width: 98, height: 99}));
+		} catch (e) {
+			// nothing
+		}
+
+		assert.htmlEqual(target.innerHTML, `
+			<p>2, 11, 2</p>
+			<p>9506, 28811, 98</p>
+		`);
+	}
+};

test/runtime/samples/const-tag-await-then-destructuring-computed-in-computed/main.svelte

@@ -0,0 +1,27 @@
+<script>
+	export let promise1 = {length: 5, width: 3, height: 4};
+	export let promise2 = {length: 12, width: 5, height: 13};
+	export let permutation = [1, 2, 3];
+
+	function calculate(length, width, height) {
+		return { 
+			'1-Dimensions': [length, width, height],
+			'2-Dimensions': [length * width, width * height, length * height],
+			'3-Dimensions': [length * width * height, length + width + height, length * width + width * height + length * height]
+		};
+	}
+
+  const th = 'th';
+</script>
+
+{#await promise1 then { length, width, height }}
+	{@const { [0]: a, [1]: b, [2]: c } = permutation}
+	{@const { [`${a}-Dimensions`]: { [c - 1]: first }, [`${b}-Dimensions`]: { [b - 1]: second }, [`${c}-Dimensions`]: { [a - 1]: third } } = calculate(length, width, height) }
+	<p>{first}, {second}, {third}</p>
+{/await}
+
+{#await promise2 catch { [`leng${th}`]: l, [`wid${th}`]: w, height: h }}
+	{@const [a, b, c] = permutation}
+	{@const { [`${a}-Dimensions`]: { [c - 1]: first }, [`${b}-Dimensions`]: { [b - 1]: second }, [`${c}-Dimensions`]: { [a - 1]: third } } = calculate(l, w, h) } 
+	<p>{first}, {second}, {third}</p>
+{/await}

test/runtime/samples/const-tag-each-destructure-computed-in-computed/_config.js

@@ -0,0 +1,15 @@
+export default {
+	html: `
+		<button>6, 12, 8, 24</button>
+		<button>45, 35, 63, 315</button>
+		<button>60, 48, 80, 480</button>
+	`,
+
+	async test({ component, target, assert }) {
+		component.boxes = [{ length: 10, width: 20, height: 30 }];
+
+		assert.htmlEqual(target.innerHTML, 
+			'<button>200, 600, 300, 6000</button>'
+		);
+	}
+};

test/runtime/samples/const-tag-each-destructure-computed-in-computed/main.svelte

@@ -0,0 +1,44 @@
+<script>
+	export let boxes = [
+		{length: 2, width: 3, height: 4},
+		{length: 9, width: 5, height: 7},
+		{length: 10, width: 6, height: 8}
+	];
+
+	function calculate(length, width, height) {
+		return { 
+				twoDimensions: {
+				bottomArea: length * width,
+				sideArea1: width * height,
+				sideArea2: length * height
+			},
+			threeDimensions: {
+				volume: length * width * height
+			}
+		};
+	}
+
+	export let dimension = 'Dimensions';
+	function changeDimension() {
+		dimension = 'DIMENSIONS';
+	}
+
+	let area = 'Area';
+  let th = 'th';
+</script>
+
+{#each boxes as { [`leng${th}`]: length, [`wid${th}`]: width, height }}
+	{@const {
+		[`two${dimension}`]: areas,
+		[`three${dimension}`]: {
+			volume
+		}
+	} = calculate(length, width, height)}
+  {@const {
+		i = 1, 
+		[`bottom${area}`]: bottom, 
+		[`side${area}${i++}`]: sideone, 
+		[`side${area}${i++}`]: sidetwo 
+	} = areas}
+	<button on:click={changeDimension}>{bottom}, {sideone}, {sidetwo}, {volume}</button>
+{/each}