[fix] handle jsdoc without tags while generating proxy types (#6884)

Fixes #6834

Co-authored-by: Rich Harris <[email protected]>

.changeset/fair-tables-peel.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+[fix] handle jsdoc without tags while generating proxy types

packages/kit/src/core/sync/write_types/index.js

@@ -489,7 +489,7 @@ export function tweak_types(content, is_server) {
 			if (node.jsDoc) {
 				// @ts-ignore
 				for (const comment of node.jsDoc) {
-					for (const tag of comment.tags) {
+					for (const tag of comment.tags ?? []) {
 						if (ts.isJSDocTypeTag(tag)) {
 							const is_fn =
 								ts.isFunctionDeclaration(value) ||

packages/kit/src/core/sync/write_types/index.spec.js

@@ -138,6 +138,33 @@ test('Rewrites types for a TypeScript module without param', () => {
 	);
 });
 
+test('Rewrites types for a TypeScript module without param and jsdoc without types', () => {
+	const source = `
+		/** test */
+		export const load: Get = () => {
+			return {
+				a: 1
+			};
+		};
+	`;
+
+	const rewritten = tweak_types(source, false);
+
+	assert.equal(rewritten?.exports, ['load']);
+	assert.equal(
+		rewritten?.code,
+		`// @ts-nocheck
+
+		/** test */
+		export const load = () => {
+			return {
+				a: 1
+			};
+		};
+	;null as any as Get;`
+	);
+});
+
 test('Rewrites types for a JavaScript module with `function`', () => {
 	const source = `
 		/** @type {import('./$types').Get} */