Revert "fix: stricter validation for component exports (#10430)"

This reverts commit dab0a43.

Author: Rich-Harris

.changeset/odd-taxis-retire.md

@@ -170,12 +170,8 @@ const runes = {
 	'invalid-legacy-export': () => `Cannot use \`export let\` in runes mode — use $props instead`,
 	/** @param {string} rune */
 	'invalid-rune-usage': (rune) => `Cannot use ${rune} rune in non-runes mode`,
-	'invalid-state-export': () =>
-		`Cannot export state if it is reassigned. Either export a function returning the state value or only mutate the state value's properties`,
-	'invalid-derived-export': () =>
-		`Cannot export derived state. To expose the current derived value, export a function returning its value`,
-	'invalid-prop-export': () =>
-		`Cannot export properties. To expose the current value of a property, export a function returning its value`,
+	'invalid-state-export': () => `Cannot export state if it is reassigned`,
+	'invalid-derived-export': () => `Cannot export derived state`,
 	'invalid-props-id': () => `$props() can only be used with an object destructuring pattern`,
 	'invalid-props-pattern': () =>
 		`$props() assignment must not contain nested properties or computed keys`,

packages/svelte/src/compiler/errors.js

@@ -733,10 +733,6 @@ function validate_export(node, scope, name) {
 	const binding = scope.get(name);
 	if (!binding) return;
 
-	if (binding.kind === 'prop') {
-		error(node, 'invalid-prop-export');
-	}
-
 	if (binding.kind === 'derived') {
 		error(node, 'invalid-derived-export');
 	}
@@ -964,20 +960,10 @@ export const validation_runes = merge(validation, a11y_validators, {
 		if (node.label.name !== '$' || path.at(-1)?.type !== 'Program') return;
 		error(node, 'invalid-legacy-reactive-statement');
 	},
-	ExportNamedDeclaration(node, { state, next }) {
+	ExportNamedDeclaration(node, { state }) {
 		if (node.declaration?.type !== 'VariableDeclaration') return;
-
-		// visit children, so bindings are correctly initialised
-		next();
-
-		for (const declarator of node.declaration.declarations) {
-			for (const id of extract_identifiers(declarator.id)) {
-				validate_export(node, state.scope, id.name);
-			}
-		}
-
-		if (state.analysis.instance.scope !== state.scope) return;
 		if (node.declaration.kind !== 'let') return;
+		if (state.analysis.instance.scope !== state.scope) return;
 		error(node, 'invalid-legacy-export');
 	},
 	ExportSpecifier(node, { state }) {

packages/svelte/src/compiler/phases/2-analyze/validation.js

@@ -3,7 +3,7 @@ import { test } from '../../test';
 export default test({
 	error: {
 		code: 'invalid-derived-export',
-		message:
-			'Cannot export derived state. To expose the current derived value, export a function returning its value'
+		message: 'Cannot export derived state',
+		position: [24, 66]
 	}
 });

packages/svelte/tests/compiler-errors/samples/export-derived-state/_config.js

@@ -3,8 +3,7 @@ import { test } from '../../test';
 export default test({
 	error: {
 		code: 'invalid-state-export',
-		message:
-			"Cannot export state if it is reassigned. Either export a function returning the state value or only mutate the state value's properties",
+		message: 'Cannot export state if it is reassigned',
 		position: [46, 86]
 	}
 });

packages/svelte/tests/compiler-errors/samples/export-derived-state/main.svelte

@@ -3,8 +3,7 @@ import { test } from '../../test';
 export default test({
 	error: {
 		code: 'invalid-state-export',
-		message:
-			"Cannot export state if it is reassigned. Either export a function returning the state value or only mutate the state value's properties",
+		message: 'Cannot export state if it is reassigned',
 		position: [28, 53]
 	}
 });