From 25d0bbf4e4dcd2c95deeca1cd87127b8fe93442f Mon Sep 17 00:00:00 2001
From: Manuel Serret <mserret99@gmail.com>
Date: Sat, 28 Jun 2025 11:03:57 +0200
Subject: [PATCH 01/10] chore: update `esrap`

---
 packages/core/package.json         |  2 +-
 packages/core/tests/js/index.ts    |  4 +-
 packages/core/tests/utils.ts       | 64 ++-------------------
 packages/core/tooling/index.ts     | 91 +++++++++---------------------
 packages/core/tooling/js/common.ts | 16 +++---
 packages/core/tooling/parsers.ts   | 10 ++--
 pnpm-lock.yaml                     | 11 +++-
 7 files changed, 59 insertions(+), 139 deletions(-)

diff --git a/packages/core/package.json b/packages/core/package.json
index 8897e9904..cc4707e72 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -51,7 +51,7 @@
 		"dom-serializer": "^2.0.0",
 		"domhandler": "^5.0.3",
 		"domutils": "^3.2.2",
-		"esrap": "^1.4.9",
+		"esrap": "^2.0.0",
 		"htmlparser2": "^9.1.0",
 		"magic-string": "^0.30.17",
 		"picocolors": "^1.1.1",
diff --git a/packages/core/tests/js/index.ts b/packages/core/tests/js/index.ts
index c7f2021e6..9aca4de6a 100644
--- a/packages/core/tests/js/index.ts
+++ b/packages/core/tests/js/index.ts
@@ -16,13 +16,13 @@ for (const categoryDirectory of categoryDirectories) {
 
 				const inputFilePath = join(testDirectoryPath, 'input.ts');
 				const input = fs.existsSync(inputFilePath) ? fs.readFileSync(inputFilePath, 'utf8') : '';
-				const ast = parseScript(input);
+				const { ast, comments } = parseScript(input);
 
 				// dynamic imports always need to provide the path inline for static analysis
 				const module = await import(`./${categoryDirectory}/${testName}/run.ts`);
 				module.run(ast);
 
-				let output = serializeScript(ast, input);
+				let output = serializeScript(ast, comments, input);
 				if (!output.endsWith('\n')) output += '\n';
 				await expect(output).toMatchFileSnapshot(`${testDirectoryPath}/output.ts`);
 			});
diff --git a/packages/core/tests/utils.ts b/packages/core/tests/utils.ts
index 37979d0be..ef3272504 100644
--- a/packages/core/tests/utils.ts
+++ b/packages/core/tests/utils.ts
@@ -4,7 +4,6 @@ import {
 	parseScript,
 	serializeScript,
 	guessIndentString,
-	guessQuoteStyle,
 	type AstTypes
 } from '../tooling/index.ts';
 
@@ -48,57 +47,6 @@ test('guessIndentString - eight spaces', () => {
 	expect(guessIndentString(code)).toBe('        ');
 });
 
-test('guessQuoteStyle - single simple', () => {
-	const code = dedent`
-    console.log('asd');
-    `;
-	const ast = parseScript(code);
-
-	expect(guessQuoteStyle(ast)).toBe('single');
-});
-
-test('guessQuoteStyle - single complex', () => {
-	const code = dedent`
-    import foo from 'bar';
-
-    console.log("bar");
-    const foobar = 'foo';
-    `;
-	const ast = parseScript(code);
-
-	expect(guessQuoteStyle(ast)).toBe('single');
-});
-
-test('guessQuoteStyle - double simple', () => {
-	const code = dedent`
-    console.log("asd");
-    `;
-	const ast = parseScript(code);
-
-	expect(guessQuoteStyle(ast)).toBe('double');
-});
-
-test('guessQuoteStyle - double complex', () => {
-	const code = dedent`
-    import foo from 'bar';
-
-    console.log("bar");
-    const foobar = "foo";
-    `;
-	const ast = parseScript(code);
-
-	expect(guessQuoteStyle(ast)).toBe('double');
-});
-
-test('guessQuoteStyle - no quotes', () => {
-	const code = dedent`
-    const foo = true;
-    `;
-	const ast = parseScript(code);
-
-	expect(guessQuoteStyle(ast)).toBe(undefined);
-});
-
 const newVariableDeclaration: AstTypes.VariableDeclaration = {
 	type: 'VariableDeclaration',
 	kind: 'const',
@@ -126,13 +74,13 @@ test('integration - simple', () => {
         const foobar = "foo";
     }
     `;
-	const ast = parseScript(code);
+	const { ast, comments } = parseScript(code);
 	const method = ast.body[1] as AstTypes.FunctionDeclaration;
 
 	method.body.body.push(newVariableDeclaration);
 
 	// new variable is added with correct indentation and matching quotes
-	expect(serializeScript(ast, code)).toMatchInlineSnapshot(`
+	expect(serializeScript(ast, comments, code)).toMatchInlineSnapshot(`
 		"import foo from 'bar';
 
 		function bar() {
@@ -153,13 +101,13 @@ test('integration - simple 2', () => {
       const foobar = 'foo';
     }
     `;
-	const ast = parseScript(code);
+	const { ast, comments } = parseScript(code);
 	const method = ast.body[1] as AstTypes.FunctionDeclaration;
 
 	method.body.body.push(newVariableDeclaration);
 
 	// new variable is added with correct indentation and matching quotes
-	expect(serializeScript(ast, code)).toMatchInlineSnapshot(`
+	expect(serializeScript(ast, comments, code)).toMatchInlineSnapshot(`
 		"import foo from 'bar';
 
 		function bar() {
@@ -176,9 +124,9 @@ test('integration - preserves comments', () => {
 	  /** @type {string} */
     let foo = 'bar';
     `;
-	const ast = parseScript(code);
+	const { ast, comments } = parseScript(code);
 
-	expect(serializeScript(ast, code)).toMatchInlineSnapshot(`
+	expect(serializeScript(ast, comments, code)).toMatchInlineSnapshot(`
 		"/** @type {string} */
 		let foo = 'bar';"
 	`);
diff --git a/packages/core/tooling/index.ts b/packages/core/tooling/index.ts
index ac42aa48f..450666edb 100644
--- a/packages/core/tooling/index.ts
+++ b/packages/core/tooling/index.ts
@@ -14,6 +14,7 @@ import {
 } from 'postcss';
 import * as fleece from 'silver-fleece';
 import { print as esrapPrint } from 'esrap';
+import ts from 'esrap/languages/ts';
 import * as acorn from 'acorn';
 import { tsPlugin } from '@sveltejs/acorn-typescript';
 
@@ -47,19 +48,21 @@ export type {
 
 /**
  * Parses as string to an AST. Code below is taken from `esrap` to ensure compatibilty.
- * https://github.com/sveltejs/esrap/blob/9daf5dd43b31f17f596aa7da91678f2650666dd0/test/common.js#L12
+ * https://github.com/sveltejs/esrap/blob/920491535d31484ac5fae2327c7826839d851aed/test/common.js#L14
  */
-export function parseScript(content: string): TsEstree.Program {
+export function parseScript(content: string): {
+	ast: TsEstree.Program;
+	comments: TsEstree.Comment[];
+} {
 	const comments: TsEstree.Comment[] = [];
 
 	const acornTs = acorn.Parser.extend(tsPlugin());
 
-	// Acorn doesn't add comments to the AST by itself. This factory returns the capabilities to add them after the fact.
 	const ast = acornTs.parse(content, {
 		ecmaVersion: 'latest',
 		sourceType: 'module',
 		locations: true,
-		onComment: (block, value, start, end) => {
+		onComment: (block, value, start, end, startLoc, endLoc) => {
 			if (block && /\n/.test(value)) {
 				let a = start;
 				while (a > 0 && content[a - 1] !== '\n') a -= 1;
@@ -71,38 +74,31 @@ export function parseScript(content: string): TsEstree.Program {
 				value = value.replace(new RegExp(`^${indentation}`, 'gm'), '');
 			}
 
-			comments.push({ type: block ? 'Block' : 'Line', value, start, end });
+			comments.push({
+				type: block ? 'Block' : 'Line',
+				value,
+				start,
+				end,
+				loc: { start: startLoc as TsEstree.Position, end: endLoc as TsEstree.Position }
+			});
 		}
 	}) as TsEstree.Program;
 
-	Walker.walk(ast as TsEstree.Node, null, {
-		_(commentNode, { next }) {
-			let comment: TsEstree.Comment;
-
-			while (comments[0] && commentNode.start && comments[0].start! < commentNode.start) {
-				comment = comments.shift()!;
-				(commentNode.leadingComments ??= []).push(comment);
-			}
-
-			next();
-
-			if (comments[0]) {
-				const slice = content.slice(commentNode.end, comments[0].start);
-
-				if (/^[,) \t]*$/.test(slice)) {
-					commentNode.trailingComments = [comments.shift()!];
-				}
-			}
-		}
-	});
-
-	return ast;
+	return {
+		ast,
+		comments
+	};
 }
 
-export function serializeScript(ast: TsEstree.Node, previousContent?: string): string {
-	const { code } = esrapPrint(ast, {
-		indent: guessIndentString(previousContent),
-		quotes: guessQuoteStyle(ast)
+export function serializeScript(
+	ast: TsEstree.Node,
+	comments: TsEstree.Comment[],
+	previousContent?: string
+): string {
+	// @ts-expect-error we are still using `estree` while `esrap` is using `@typescript-eslint/types`
+	// which is causing these errors. But they are simmilar enough to work together.
+	const { code } = esrapPrint(ast, ts({ comments }), {
+		indent: guessIndentString(previousContent)
 	});
 	return code;
 }
@@ -205,36 +201,3 @@ export function guessIndentString(str: string | undefined): string {
 		return '\t';
 	}
 }
-
-export function guessQuoteStyle(ast: TsEstree.Node): 'single' | 'double' | undefined {
-	let singleCount = 0;
-	let doubleCount = 0;
-
-	Walker.walk(ast, null, {
-		Literal(node) {
-			if (node.raw && node.raw.length >= 2) {
-				// we have at least two characters in the raw string that could represent both quotes
-				const quotes = [node.raw[0], node.raw[node.raw.length - 1]];
-				for (const quote of quotes) {
-					switch (quote) {
-						case "'":
-							singleCount++;
-							break;
-						case '"':
-							doubleCount++;
-							break;
-						default:
-							break;
-					}
-				}
-			}
-		}
-	});
-
-	if (singleCount === 0 && doubleCount === 0) {
-		// new file or file without any quotes
-		return undefined;
-	}
-
-	return singleCount > doubleCount ? 'single' : 'double';
-}
diff --git a/packages/core/tooling/js/common.ts b/packages/core/tooling/js/common.ts
index 8812660e2..d249b693b 100644
--- a/packages/core/tooling/js/common.ts
+++ b/packages/core/tooling/js/common.ts
@@ -93,7 +93,7 @@ export function areNodesEqual(node: AstTypes.Node, otherNode: AstTypes.Node): bo
 
 	const nodeClone = stripAst(decircular(node), ['loc', 'raw']);
 	const otherNodeClone = stripAst(decircular(otherNode), ['loc', 'raw']);
-	return serializeScript(nodeClone) === serializeScript(otherNodeClone);
+	return serializeScript(nodeClone, []) === serializeScript(otherNodeClone, []);
 }
 
 export function createBlockStatement(): AstTypes.BlockStatement {
@@ -118,18 +118,18 @@ export function appendFromString(
 	node: AstTypes.BlockStatement | AstTypes.Program,
 	options: { code: string }
 ): void {
-	const program = parseScript(dedent(options.code));
+	const { ast } = parseScript(dedent(options.code));
 
-	for (const childNode of program.body) {
+	for (const childNode of ast.body) {
 		// @ts-expect-error
 		node.body.push(childNode);
 	}
 }
 
 export function parseExpression(code: string): AstTypes.Expression {
-	const program = parseScript(dedent(code));
-	stripAst(program, ['raw']);
-	const statement = program.body[0]!;
+	const { ast } = parseScript(dedent(code));
+	stripAst(ast, ['raw']);
+	const statement = ast.body[0]!;
 	if (statement.type !== 'ExpressionStatement') {
 		throw new Error('Code provided was not an expression');
 	}
@@ -142,8 +142,8 @@ export function parseStatement(code: string): AstTypes.Statement {
 }
 
 export function parseFromString<T extends AstTypes.Node>(code: string): T {
-	const program = parseScript(dedent(code));
-	const statement = program.body[0]!;
+	const { ast } = parseScript(dedent(code));
+	const statement = ast.body[0]!;
 
 	return statement as T;
 }
diff --git a/packages/core/tooling/parsers.ts b/packages/core/tooling/parsers.ts
index f7764d34f..7d39bad23 100644
--- a/packages/core/tooling/parsers.ts
+++ b/packages/core/tooling/parsers.ts
@@ -6,11 +6,13 @@ type ParseBase = {
 	generateCode(): string;
 };
 
-export function parseScript(source: string): { ast: utils.AstTypes.Program } & ParseBase {
-	const ast = utils.parseScript(source);
-	const generateCode = () => utils.serializeScript(ast, source);
+export function parseScript(
+	source: string
+): { ast: utils.AstTypes.Program; comments: utils.AstTypes.Comment[] } & ParseBase {
+	const { ast, comments } = utils.parseScript(source);
+	const generateCode = () => utils.serializeScript(ast, comments, source);
 
-	return { ast, source, generateCode };
+	return { ast, comments, source, generateCode };
 }
 
 export function parseCss(source: string): { ast: utils.CssAst } & ParseBase {
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 959d7df38..0f3596458 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -170,8 +170,8 @@ importers:
         specifier: ^3.2.2
         version: 3.2.2
       esrap:
-        specifier: ^1.4.9
-        version: 1.4.9
+        specifier: ^2.0.0
+        version: 2.0.1
       htmlparser2:
         specifier: ^9.1.0
         version: 9.1.0
@@ -1299,6 +1299,9 @@ packages:
   esrap@1.4.9:
     resolution: {integrity: sha512-3OMlcd0a03UGuZpPeUC1HxR3nA23l+HEyCiZw3b3FumJIN9KphoGzDJKMXI1S72jVS1dsenDyQC0kJlO1U9E1g==}
 
+  esrap@2.0.1:
+    resolution: {integrity: sha512-6n1JodkxeMvyTDCog7J//t8Yti//fGicZgtFLko6h/aEpc54BK9O8k9cZgC2J8+2Dh1U5uYIxuJWSsylybvFBA==}
+
   esrecurse@4.3.0:
     resolution: {integrity: sha512-KmfKL3b6G+RXvP8N1vr3Tq1kL/oCFgn2NYXEtqP8/L3pKapUA4G8cFVaoF3SU323CD4XypR/ffioHmkti6/Tag==}
     engines: {node: '>=4.0'}
@@ -3298,6 +3301,10 @@ snapshots:
     dependencies:
       '@jridgewell/sourcemap-codec': 1.5.0
 
+  esrap@2.0.1:
+    dependencies:
+      '@jridgewell/sourcemap-codec': 1.5.0
+
   esrecurse@4.3.0:
     dependencies:
       estraverse: 5.3.0

From 9394c80a3803bc60dadb2ff40636509e620d1766 Mon Sep 17 00:00:00 2001
From: Manuel Serret <mserret99@gmail.com>
Date: Sun, 26 Oct 2025 06:55:29 +0100
Subject: [PATCH 02/10] use esrap pkg.pr.new

---
 packages/core/package.json     |  2 +-
 packages/core/tooling/index.ts |  7 ++++---
 pnpm-lock.yaml                 | 11 ++++++-----
 3 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/packages/core/package.json b/packages/core/package.json
index cc4707e72..350e3fdcf 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -51,7 +51,7 @@
 		"dom-serializer": "^2.0.0",
 		"domhandler": "^5.0.3",
 		"domutils": "^3.2.2",
-		"esrap": "^2.0.0",
+		"esrap": "https://pkg.pr.new/sveltejs/esrap@718afce",
 		"htmlparser2": "^9.1.0",
 		"magic-string": "^0.30.17",
 		"picocolors": "^1.1.1",
diff --git a/packages/core/tooling/index.ts b/packages/core/tooling/index.ts
index 450666edb..1d56b51e8 100644
--- a/packages/core/tooling/index.ts
+++ b/packages/core/tooling/index.ts
@@ -14,7 +14,7 @@ import {
 } from 'postcss';
 import * as fleece from 'silver-fleece';
 import { print as esrapPrint } from 'esrap';
-import ts from 'esrap/languages/ts';
+import ts, { type AdditionalComment } from 'esrap/languages/ts';
 import * as acorn from 'acorn';
 import { tsPlugin } from '@sveltejs/acorn-typescript';
 
@@ -93,11 +93,12 @@ export function parseScript(content: string): {
 export function serializeScript(
 	ast: TsEstree.Node,
 	comments: TsEstree.Comment[],
-	previousContent?: string
+	previousContent?: string,
+	additionalComments?: WeakMap<TsEstree.Node, AdditionalComment[]>
 ): string {
 	// @ts-expect-error we are still using `estree` while `esrap` is using `@typescript-eslint/types`
 	// which is causing these errors. But they are simmilar enough to work together.
-	const { code } = esrapPrint(ast, ts({ comments }), {
+	const { code } = esrapPrint(ast, ts({ comments, additionalComments }), {
 		indent: guessIndentString(previousContent)
 	});
 	return code;
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 8b9000f76..af8676d00 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -170,8 +170,8 @@ importers:
         specifier: ^3.2.2
         version: 3.2.2
       esrap:
-        specifier: ^2.0.0
-        version: 2.0.1
+        specifier: https://pkg.pr.new/sveltejs/esrap@718afce
+        version: https://pkg.pr.new/sveltejs/esrap@718afce
       htmlparser2:
         specifier: ^9.1.0
         version: 9.1.0
@@ -1301,8 +1301,9 @@ packages:
   esrap@1.4.9:
     resolution: {integrity: sha512-3OMlcd0a03UGuZpPeUC1HxR3nA23l+HEyCiZw3b3FumJIN9KphoGzDJKMXI1S72jVS1dsenDyQC0kJlO1U9E1g==}
 
-  esrap@2.0.1:
-    resolution: {integrity: sha512-6n1JodkxeMvyTDCog7J//t8Yti//fGicZgtFLko6h/aEpc54BK9O8k9cZgC2J8+2Dh1U5uYIxuJWSsylybvFBA==}
+  esrap@https://pkg.pr.new/sveltejs/esrap@718afce:
+    resolution: {tarball: https://pkg.pr.new/sveltejs/esrap@718afce}
+    version: 2.1.0
 
   esrecurse@4.3.0:
     resolution: {integrity: sha512-KmfKL3b6G+RXvP8N1vr3Tq1kL/oCFgn2NYXEtqP8/L3pKapUA4G8cFVaoF3SU323CD4XypR/ffioHmkti6/Tag==}
@@ -3306,7 +3307,7 @@ snapshots:
     dependencies:
       '@jridgewell/sourcemap-codec': 1.5.0
 
-  esrap@2.0.1:
+  esrap@https://pkg.pr.new/sveltejs/esrap@718afce:
     dependencies:
       '@jridgewell/sourcemap-codec': 1.5.0
 

From 79f262eef3b6486b711787f2b7e69585d8e071b5 Mon Sep 17 00:00:00 2001
From: Manuel Serret <mserret99@gmail.com>
Date: Sun, 26 Oct 2025 06:55:54 +0100
Subject: [PATCH 03/10] fix `svelte-kit` adapter addon

---
 packages/addons/sveltekit-adapter/index.ts | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/packages/addons/sveltekit-adapter/index.ts b/packages/addons/sveltekit-adapter/index.ts
index 3d8d9fc7c..f3ae2bcf9 100644
--- a/packages/addons/sveltekit-adapter/index.ts
+++ b/packages/addons/sveltekit-adapter/index.ts
@@ -49,7 +49,7 @@ export default defineAddon({
 		sv.devDependency(adapter.package, adapter.version);
 
 		sv.file('svelte.config.js', (content) => {
-			const { ast, generateCode } = parseScript(content);
+			const { ast, comments, generateCode } = parseScript(content);
 
 			// finds any existing adapter's import declaration
 			const importDecls = ast.body.filter((n) => n.type === 'ImportDeclaration');
@@ -79,12 +79,20 @@ export default defineAddon({
 			) as AstTypes.Property | undefined;
 
 			if (kitConfig && kitConfig.value.type === 'ObjectExpression') {
-				const adapterProp = kitConfig.value.properties.find(
-					(p) => p.type === 'Property' && p.key.type === 'Identifier' && p.key.name === 'adapter'
+				// removes any existing adapter auto comments
+				const adapterAutoComments = comments.filter(
+					(c) =>
+						c.loc &&
+						kitConfig.loc &&
+						c.loc.start.line >= kitConfig.loc.start.line &&
+						c.loc.end.line <= kitConfig.loc.end.line
+				);
+				// modify the array in place
+				comments.splice(
+					0,
+					comments.length,
+					...comments.filter((c) => !adapterAutoComments.includes(c))
 				);
-				if (adapterProp) {
-					adapterProp.leadingComments = [];
-				}
 
 				// only overrides the `adapter` property so we can reset it's args
 				object.overrideProperties(kitConfig.value, {

From 7c0c0d2592a586291de0af0a4c4ec4db6be5eede Mon Sep 17 00:00:00 2001
From: Manuel Serret <mserret99@gmail.com>
Date: Sun, 26 Oct 2025 07:00:44 +0100
Subject: [PATCH 04/10] remove useless comment

---
 packages/core/tests/js/object/create/run.ts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/packages/core/tests/js/object/create/run.ts b/packages/core/tests/js/object/create/run.ts
index 8bdd272f5..5b19937e0 100644
--- a/packages/core/tests/js/object/create/run.ts
+++ b/packages/core/tests/js/object/create/run.ts
@@ -37,6 +37,5 @@ export function run(ast: AstTypes.Program): void {
 		name: 'created2',
 		value: createdObject2
 	});
-	createdVariable2.leadingComments = [{ type: 'Line', value: ' prettier-ignore' }];
 	ast.body.push(createdVariable2);
 }

From f41da148e0ea805c8643189efeff7406655e8f8b Mon Sep 17 00:00:00 2001
From: Manuel Serret <mserret99@gmail.com>
Date: Sun, 26 Oct 2025 07:08:34 +0100
Subject: [PATCH 05/10] fix eslint

---
 packages/addons/eslint/index.ts  | 12 +++++++-----
 packages/core/tooling/index.ts   |  4 +++-
 packages/core/tooling/parsers.ts | 16 ++++++++++------
 3 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/packages/addons/eslint/index.ts b/packages/addons/eslint/index.ts
index e0130e5b4..80424282d 100644
--- a/packages/addons/eslint/index.ts
+++ b/packages/addons/eslint/index.ts
@@ -52,7 +52,7 @@ export default defineAddon({
 		});
 
 		sv.file('eslint.config.js', (content) => {
-			const { ast, generateCode } = parseScript(content);
+			const { ast, additionalComments, generateCode } = parseScript(content);
 
 			const eslintConfigs: Array<AstTypes.Expression | AstTypes.SpreadElement> = [];
 			imports.addDefault(ast, { from: './svelte.config.js', as: 'svelteConfig' });
@@ -84,18 +84,20 @@ export default defineAddon({
 			if (rules.properties[0].type !== 'Property') {
 				throw new Error('rules.properties[0].type !== "Property"');
 			}
-			rules.properties[0].key.leadingComments = [
+			additionalComments.set(rules.properties[0].key, [
 				{
 					type: 'Line',
 					value:
-						' typescript-eslint strongly recommend that you do not use the no-undef lint rule on TypeScript projects.'
+						' typescript-eslint strongly recommend that you do not use the no-undef lint rule on TypeScript projects.',
+					position: 'leading'
 				},
 				{
 					type: 'Line',
 					value:
-						' see: https://typescript-eslint.io/troubleshooting/faqs/eslint/#i-get-errors-from-the-no-undef-rule-about-global-variables-not-being-defined-even-though-there-are-no-typescript-errors'
+						' see: https://typescript-eslint.io/troubleshooting/faqs/eslint/#i-get-errors-from-the-no-undef-rule-about-global-variables-not-being-defined-even-though-there-are-no-typescript-errors',
+					position: 'leading'
 				}
-			];
+			]);
 
 			const globalsConfig = object.create({
 				languageOptions: {
diff --git a/packages/core/tooling/index.ts b/packages/core/tooling/index.ts
index 1d56b51e8..181270aa1 100644
--- a/packages/core/tooling/index.ts
+++ b/packages/core/tooling/index.ts
@@ -53,6 +53,7 @@ export type {
 export function parseScript(content: string): {
 	ast: TsEstree.Program;
 	comments: TsEstree.Comment[];
+	additionalComments: WeakMap<TsEstree.Node, AdditionalComment[]>;
 } {
 	const comments: TsEstree.Comment[] = [];
 
@@ -86,7 +87,8 @@ export function parseScript(content: string): {
 
 	return {
 		ast,
-		comments
+		comments,
+		additionalComments: new WeakMap()
 	};
 }
 
diff --git a/packages/core/tooling/parsers.ts b/packages/core/tooling/parsers.ts
index 7d39bad23..cd6f3b568 100644
--- a/packages/core/tooling/parsers.ts
+++ b/packages/core/tooling/parsers.ts
@@ -1,18 +1,22 @@
 import * as utils from './index.ts';
 import MagicString from 'magic-string';
+import type { TsEstree } from './js/ts-estree.ts';
+import type { AdditionalComment } from 'esrap/languages/ts';
 
 type ParseBase = {
 	source: string;
 	generateCode(): string;
 };
 
-export function parseScript(
-	source: string
-): { ast: utils.AstTypes.Program; comments: utils.AstTypes.Comment[] } & ParseBase {
-	const { ast, comments } = utils.parseScript(source);
-	const generateCode = () => utils.serializeScript(ast, comments, source);
+export function parseScript(source: string): {
+	ast: utils.AstTypes.Program;
+	comments: utils.AstTypes.Comment[];
+	additionalComments: WeakMap<TsEstree.Node, AdditionalComment[]>;
+} & ParseBase {
+	const { ast, comments, additionalComments } = utils.parseScript(source);
+	const generateCode = () => utils.serializeScript(ast, comments, source, additionalComments);
 
-	return { ast, comments, source, generateCode };
+	return { ast, comments, additionalComments, source, generateCode };
 }
 
 export function parseCss(source: string): { ast: utils.CssAst } & ParseBase {

From 7307cc4d6333e22fbead282ffd6edb300cb49076 Mon Sep 17 00:00:00 2001
From: Manuel Serret <mserret99@gmail.com>
Date: Sun, 26 Oct 2025 07:35:06 +0100
Subject: [PATCH 06/10] fix eslint

---
 packages/addons/eslint/index.ts               |  4 +-
 .../core/tests/js/common/jsdoc-comment/run.ts |  6 +--
 .../tests/js/common/jsdoc-type-comment/run.ts |  6 +--
 packages/core/tests/js/index.ts               |  6 +--
 packages/core/tooling/index.ts                |  7 +++-
 packages/core/tooling/js/common.ts            | 41 ++++++++++++++-----
 packages/core/tooling/js/index.ts             |  2 +-
 packages/core/tooling/parsers.ts              |  4 +-
 8 files changed, 49 insertions(+), 27 deletions(-)

diff --git a/packages/addons/eslint/index.ts b/packages/addons/eslint/index.ts
index 80424282d..d20dd0df2 100644
--- a/packages/addons/eslint/index.ts
+++ b/packages/addons/eslint/index.ts
@@ -154,7 +154,9 @@ export default defineAddon({
 
 			// type annotate config
 			if (!typescript)
-				common.addJsDocTypeComment(astNode, { type: "import('eslint').Linter.Config[]" });
+				common.addJsDocTypeComment(astNode, additionalComments, {
+					type: "import('eslint').Linter.Config[]"
+				});
 
 			if (typescript) imports.addDefault(ast, { from: 'typescript-eslint', as: 'ts' });
 			imports.addNamed(ast, { from: 'node:url', imports: ['fileURLToPath'] });
diff --git a/packages/core/tests/js/common/jsdoc-comment/run.ts b/packages/core/tests/js/common/jsdoc-comment/run.ts
index c0b6c06f1..15d0369b9 100644
--- a/packages/core/tests/js/common/jsdoc-comment/run.ts
+++ b/packages/core/tests/js/common/jsdoc-comment/run.ts
@@ -1,9 +1,9 @@
-import { common, type AstTypes } from '@sveltejs/cli-core/js';
+import { common, type AdditionalCommentMap, type AstTypes } from '@sveltejs/cli-core/js';
 
-export function run(ast: AstTypes.Program): void {
+export function run(ast: AstTypes.Program, additionalComments: AdditionalCommentMap): void {
 	const functionDeclaration = ast.body[0] as AstTypes.FunctionDeclaration;
 
-	common.addJsDocComment(functionDeclaration, {
+	common.addJsDocComment(functionDeclaration, additionalComments, {
 		params: { 'import("$lib/paraglide/runtime").AvailableLanguageTag': 'newLanguage' }
 	});
 }
diff --git a/packages/core/tests/js/common/jsdoc-type-comment/run.ts b/packages/core/tests/js/common/jsdoc-type-comment/run.ts
index 9b5e5a065..5074afd58 100644
--- a/packages/core/tests/js/common/jsdoc-type-comment/run.ts
+++ b/packages/core/tests/js/common/jsdoc-type-comment/run.ts
@@ -1,13 +1,13 @@
-import { common, variables, type AstTypes } from '@sveltejs/cli-core/js';
+import { common, variables, type AdditionalCommentMap, type AstTypes } from '@sveltejs/cli-core/js';
 
-export function run(ast: AstTypes.Program): void {
+export function run(ast: AstTypes.Program, additionalComments: AdditionalCommentMap): void {
 	const declaration = variables.declaration(ast, {
 		kind: 'const',
 		name: 'foo',
 		value: { type: 'Literal', value: 42 }
 	});
 
-	common.addJsDocTypeComment(declaration, {
+	common.addJsDocTypeComment(declaration, additionalComments, {
 		type: 'number'
 	});
 
diff --git a/packages/core/tests/js/index.ts b/packages/core/tests/js/index.ts
index 9aca4de6a..bc32a5c83 100644
--- a/packages/core/tests/js/index.ts
+++ b/packages/core/tests/js/index.ts
@@ -16,13 +16,13 @@ for (const categoryDirectory of categoryDirectories) {
 
 				const inputFilePath = join(testDirectoryPath, 'input.ts');
 				const input = fs.existsSync(inputFilePath) ? fs.readFileSync(inputFilePath, 'utf8') : '';
-				const { ast, comments } = parseScript(input);
+				const { ast, comments, additionalComments } = parseScript(input);
 
 				// dynamic imports always need to provide the path inline for static analysis
 				const module = await import(`./${categoryDirectory}/${testName}/run.ts`);
-				module.run(ast);
+				module.run(ast, additionalComments);
 
-				let output = serializeScript(ast, comments, input);
+				let output = serializeScript(ast, comments, input, additionalComments);
 				if (!output.endsWith('\n')) output += '\n';
 				await expect(output).toMatchFileSnapshot(`${testDirectoryPath}/output.ts`);
 			});
diff --git a/packages/core/tooling/index.ts b/packages/core/tooling/index.ts
index 181270aa1..d2f1aa0f3 100644
--- a/packages/core/tooling/index.ts
+++ b/packages/core/tooling/index.ts
@@ -18,6 +18,8 @@ import ts, { type AdditionalComment } from 'esrap/languages/ts';
 import * as acorn from 'acorn';
 import { tsPlugin } from '@sveltejs/acorn-typescript';
 
+type AdditionalCommentMap = WeakMap<TsEstree.Node, AdditionalComment[]>;
+
 export {
 	// html
 	Document as HtmlDocument,
@@ -41,6 +43,7 @@ export type {
 
 	// js
 	TsEstree as AstTypes,
+	AdditionalCommentMap,
 
 	//css
 	CssChildNode
@@ -53,7 +56,7 @@ export type {
 export function parseScript(content: string): {
 	ast: TsEstree.Program;
 	comments: TsEstree.Comment[];
-	additionalComments: WeakMap<TsEstree.Node, AdditionalComment[]>;
+	additionalComments: AdditionalCommentMap;
 } {
 	const comments: TsEstree.Comment[] = [];
 
@@ -96,7 +99,7 @@ export function serializeScript(
 	ast: TsEstree.Node,
 	comments: TsEstree.Comment[],
 	previousContent?: string,
-	additionalComments?: WeakMap<TsEstree.Node, AdditionalComment[]>
+	additionalComments?: AdditionalCommentMap
 ): string {
 	// @ts-expect-error we are still using `estree` while `esrap` is using `@typescript-eslint/types`
 	// which is causing these errors. But they are simmilar enough to work together.
diff --git a/packages/core/tooling/js/common.ts b/packages/core/tooling/js/common.ts
index d249b693b..1f51dcf6a 100644
--- a/packages/core/tooling/js/common.ts
+++ b/packages/core/tooling/js/common.ts
@@ -1,18 +1,30 @@
-import { type AstTypes, Walker, parseScript, serializeScript, stripAst } from '../index.ts';
+import {
+	type AdditionalCommentMap,
+	type AstTypes,
+	Walker,
+	parseScript,
+	serializeScript,
+	stripAst
+} from '../index.ts';
 import decircular from 'decircular';
 import dedent from 'dedent';
 
-export function addJsDocTypeComment(node: AstTypes.Node, options: { type: string }): void {
+export function addJsDocTypeComment(
+	node: AstTypes.Node,
+	additionalComments: AdditionalCommentMap,
+	options: { type: string }
+): void {
 	const comment: AstTypes.Comment = {
 		type: 'Block',
 		value: `* @type {${options.type}} `
 	};
 
-	addComment(node, comment);
+	addComment(node, additionalComments, comment);
 }
 
 export function addJsDocComment(
 	node: AstTypes.Node,
+	additionalComments: AdditionalCommentMap,
 	options: { params: Record<string, string> }
 ): void {
 	const commentLines: string[] = [];
@@ -25,16 +37,23 @@ export function addJsDocComment(
 		value: `*\n * ${commentLines.join('\n * ')}\n `
 	};
 
-	addComment(node, comment);
+	addComment(node, additionalComments, comment);
 }
 
-function addComment(node: AstTypes.Node, comment: AstTypes.Comment) {
-	node.leadingComments ??= [];
-
-	const found = node.leadingComments.find(
-		(item) => item.type === 'Block' && item.value === comment.value
-	);
-	if (!found) node.leadingComments.push(comment);
+function addComment(
+	node: AstTypes.Node,
+	additionalComments: AdditionalCommentMap,
+	comment: AstTypes.Comment
+) {
+	const found = additionalComments
+		.get(node)
+		?.find((item) => item.type === 'Block' && item.value === comment.value);
+
+	if (!found) {
+		const comments = additionalComments.get(node) ?? [];
+		comments.push({ ...comment, position: 'leading' });
+		additionalComments.set(node, comments);
+	}
 }
 
 export function typeAnnotate(
diff --git a/packages/core/tooling/js/index.ts b/packages/core/tooling/js/index.ts
index 0b4c6e632..206d49d5a 100644
--- a/packages/core/tooling/js/index.ts
+++ b/packages/core/tooling/js/index.ts
@@ -7,4 +7,4 @@ export * as variables from './variables.ts';
 export * as exports from './exports.ts';
 export * as kit from './kit.ts';
 export * as vite from './vite.ts';
-export type { AstTypes } from '../index.ts';
+export type { AstTypes, AdditionalCommentMap } from '../index.ts';
diff --git a/packages/core/tooling/parsers.ts b/packages/core/tooling/parsers.ts
index cd6f3b568..12c2131e5 100644
--- a/packages/core/tooling/parsers.ts
+++ b/packages/core/tooling/parsers.ts
@@ -1,7 +1,5 @@
 import * as utils from './index.ts';
 import MagicString from 'magic-string';
-import type { TsEstree } from './js/ts-estree.ts';
-import type { AdditionalComment } from 'esrap/languages/ts';
 
 type ParseBase = {
 	source: string;
@@ -11,7 +9,7 @@ type ParseBase = {
 export function parseScript(source: string): {
 	ast: utils.AstTypes.Program;
 	comments: utils.AstTypes.Comment[];
-	additionalComments: WeakMap<TsEstree.Node, AdditionalComment[]>;
+	additionalComments: utils.AdditionalCommentMap;
 } & ParseBase {
 	const { ast, comments, additionalComments } = utils.parseScript(source);
 	const generateCode = () => utils.serializeScript(ast, comments, source, additionalComments);

From 6df65fc99717d31837b57e63aaa72f9e8810f48f Mon Sep 17 00:00:00 2001
From: Manuel Serret <mserret99@gmail.com>
Date: Sun, 26 Oct 2025 07:39:04 +0100
Subject: [PATCH 07/10] add changed tests

---
 packages/core/tests/js/object/create/output.ts        |  8 +-------
 packages/core/tests/js/vite/add-plugin-mode/output.ts |  2 ++
 packages/core/tests/js/vite/with-satisfies/output.ts  | 11 ++++++-----
 packages/core/tests/utils.ts                          |  2 +-
 4 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/packages/core/tests/js/object/create/output.ts b/packages/core/tests/js/object/create/output.ts
index 28ad96e4f..df190f0f4 100644
--- a/packages/core/tests/js/object/create/output.ts
+++ b/packages/core/tests/js/object/create/output.ts
@@ -1,15 +1,9 @@
 const empty = {};
 const created = { foo: 1, bar: 'string' };
 
-// prettier-ignore
 const created2 = {
 	foo: 1,
 	bar: 'string',
 	object: { foo: 'hello', nested: { bar: 'world' } },
-	array: [
-		123,
-		'hello',
-		{ foo: 'bar', bool: true },
-		[456, '789']
-	]
+	array: [123, 'hello', { foo: 'bar', bool: true }, [456, '789']]
 };
diff --git a/packages/core/tests/js/vite/add-plugin-mode/output.ts b/packages/core/tests/js/vite/add-plugin-mode/output.ts
index f112d5fcc..df6d4692a 100644
--- a/packages/core/tests/js/vite/add-plugin-mode/output.ts
+++ b/packages/core/tests/js/vite/add-plugin-mode/output.ts
@@ -7,8 +7,10 @@ import { defineConfig } from 'vite';
 export default defineConfig({
 	plugins: [
 		firstPlugin(),
+
 		// a default plugin
 		sveltekit(),
+
 		middlePlugin(),
 		lastPlugin()
 	]
diff --git a/packages/core/tests/js/vite/with-satisfies/output.ts b/packages/core/tests/js/vite/with-satisfies/output.ts
index 4d6ed36e0..9c43348e2 100644
--- a/packages/core/tests/js/vite/with-satisfies/output.ts
+++ b/packages/core/tests/js/vite/with-satisfies/output.ts
@@ -18,23 +18,24 @@ const config = defineConfig({
 	plugins: [
 		// all plugins
 		examples,
+
 		tailwindcss(),
 		sveltekit(),
 		kitRoutes(),
 		myPlugin()
 	],
+
 	resolve: { alias: { $lib, $routes, $scripts, $actions } },
-	build: {
-		sourcemap: true,
-		target: 'esnext',
-		cssMinify: 'lightningcss'
-	},
+	build: { sourcemap: true, target: 'esnext', cssMinify: 'lightningcss' },
+
 	css: {
 		transformer: 'lightningcss',
+
 		lightningcss: {
 			targets: browserslistToTargets(browserslist('defaults, not ie 11'))
 		}
 	},
+
 	experimental: { enableNativePlugin: true }
 }) satisfies UserConfig;
 
diff --git a/packages/core/tests/utils.ts b/packages/core/tests/utils.ts
index ef3272504..f27f91fc8 100644
--- a/packages/core/tests/utils.ts
+++ b/packages/core/tests/utils.ts
@@ -87,7 +87,7 @@ test('integration - simple', () => {
 		    console.log("bar");
 
 		    const foobar = "foo";
-		    const foobar2 = "test";
+		    const foobar2 = 'test';
 		}"
 	`);
 });

From ae784550dae249f8b34713c9ebd573f72d52e901 Mon Sep 17 00:00:00 2001
From: Manuel Serret <mserret99@gmail.com>
Date: Sun, 26 Oct 2025 07:40:21 +0100
Subject: [PATCH 08/10] thats ok too

---
 packages/core/tests/js/common/jsdoc-type-comment/output.ts | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/packages/core/tests/js/common/jsdoc-type-comment/output.ts b/packages/core/tests/js/common/jsdoc-type-comment/output.ts
index 1aa734391..e8a715681 100644
--- a/packages/core/tests/js/common/jsdoc-type-comment/output.ts
+++ b/packages/core/tests/js/common/jsdoc-type-comment/output.ts
@@ -1,2 +1 @@
-/** @type {number} */
-const foo = 42;
+/** @type {number} */ const foo = 42;

From 1982ac405e60306265e6596fd7273c9632332699 Mon Sep 17 00:00:00 2001
From: Manuel Serret <mserret99@gmail.com>
Date: Sun, 26 Oct 2025 07:51:22 +0100
Subject: [PATCH 09/10] those are ok as well

---
 .../tests/js/object/ensure-nested-property/output.ts     | 9 ++++++++-
 .../core/tests/js/object/override-property/output.ts     | 8 +++++++-
 packages/core/tests/js/object/property-node/output.ts    | 7 ++++++-
 3 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/packages/core/tests/js/object/ensure-nested-property/output.ts b/packages/core/tests/js/object/ensure-nested-property/output.ts
index 08bd5fbf9..b3824d36a 100644
--- a/packages/core/tests/js/object/ensure-nested-property/output.ts
+++ b/packages/core/tests/js/object/ensure-nested-property/output.ts
@@ -1 +1,8 @@
-const test = { a: { /** a comment */ keep: 'you', b: { c: '007' } } };
+const test = {
+	a: {
+		/** a comment */
+		keep: 'you',
+
+		b: { c: '007' }
+	}
+};
diff --git a/packages/core/tests/js/object/override-property/output.ts b/packages/core/tests/js/object/override-property/output.ts
index fbdef76fe..987c50888 100644
--- a/packages/core/tests/js/object/override-property/output.ts
+++ b/packages/core/tests/js/object/override-property/output.ts
@@ -1 +1,7 @@
-const test = { /** a comment */ foo: 2, bar: 'string2', lorem: false };
+const test = {
+	/** a comment */
+	foo: 2,
+
+	bar: 'string2',
+	lorem: false
+};
diff --git a/packages/core/tests/js/object/property-node/output.ts b/packages/core/tests/js/object/property-node/output.ts
index 98da8dea4..3719acb91 100644
--- a/packages/core/tests/js/object/property-node/output.ts
+++ b/packages/core/tests/js/object/property-node/output.ts
@@ -1 +1,6 @@
-const test = { /*a comment updated*/ foo: 1, /*aka: bond, james bond*/ james: '007' };
+const test = {
+	/** a comment */
+	foo: 1,
+
+	james: '007'
+};

From 62444cc432a419521ff58b48c4dc17eb79751c7a Mon Sep 17 00:00:00 2001
From: Manuel Serret <mserret99@gmail.com>
Date: Sun, 26 Oct 2025 08:28:09 +0100
Subject: [PATCH 10/10] fix last failing test

---
 packages/core/package.json |  2 +-
 pnpm-lock.yaml             | 10 +++++-----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/packages/core/package.json b/packages/core/package.json
index 224452035..23c9e2303 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -34,7 +34,7 @@
 		"dom-serializer": "^2.0.0",
 		"domhandler": "^5.0.3",
 		"domutils": "^3.2.2",
-		"esrap": "https://pkg.pr.new/sveltejs/esrap@718afce",
+		"esrap": "https://pkg.pr.new/sveltejs/esrap@af12b38",
 		"htmlparser2": "^9.1.0",
 		"magic-string": "^0.30.17",
 		"picocolors": "^1.1.1",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 2b189db0f..f8ccbd66c 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -167,8 +167,8 @@ importers:
         specifier: ^3.2.2
         version: 3.2.2
       esrap:
-        specifier: https://pkg.pr.new/sveltejs/esrap@718afce
-        version: https://pkg.pr.new/sveltejs/esrap@718afce
+        specifier: https://pkg.pr.new/sveltejs/esrap@af12b38
+        version: https://pkg.pr.new/sveltejs/esrap@af12b38
       htmlparser2:
         specifier: ^9.1.0
         version: 9.1.0
@@ -1339,8 +1339,8 @@ packages:
   esrap@1.4.9:
     resolution: {integrity: sha512-3OMlcd0a03UGuZpPeUC1HxR3nA23l+HEyCiZw3b3FumJIN9KphoGzDJKMXI1S72jVS1dsenDyQC0kJlO1U9E1g==}
 
-  esrap@https://pkg.pr.new/sveltejs/esrap@718afce:
-    resolution: {tarball: https://pkg.pr.new/sveltejs/esrap@718afce}
+  esrap@https://pkg.pr.new/sveltejs/esrap@af12b38:
+    resolution: {tarball: https://pkg.pr.new/sveltejs/esrap@af12b38}
     version: 2.1.0
 
   esrecurse@4.3.0:
@@ -3402,7 +3402,7 @@ snapshots:
     dependencies:
       '@jridgewell/sourcemap-codec': 1.5.5
 
-  esrap@https://pkg.pr.new/sveltejs/esrap@718afce:
+  esrap@https://pkg.pr.new/sveltejs/esrap@af12b38:
     dependencies:
       '@jridgewell/sourcemap-codec': 1.5.5