chore: explore parsers and printers

package.json

@@ -25,7 +25,7 @@
 		"@sveltejs/eslint-config": "^8.1.0",
 		"@svitejs/changesets-changelog-github-compact": "^1.2.0",
 		"@types/node": "^22.10.2",
-		"@vitest/ui": "^3.0.3",
+		"@vitest/ui": "^3.0.5",
 		"eslint": "^9.17.0",
 		"magic-string": "^0.30.15",
 		"prettier": "^3.4.2",
@@ -39,5 +39,5 @@
 		"unplugin-isolated-decl": "^0.8.3",
 		"vitest": "^3.0.5"
 	},
-	"packageManager": "pnpm@10.1.0"
+	"packageManager": "pnpm@10.2.0"
 }

packages/addons/drizzle/index.ts

@@ -191,8 +191,8 @@ export default defineAddon({
 					url: common.expressionFromString('process.env.DATABASE_URL'),
 					authToken
 				}),
-				verbose: { type: 'BooleanLiteral', value: true },
-				strict: { type: 'BooleanLiteral', value: true }
+				verbose: { type: 'Literal', value: true },
+				strict: { type: 'Literal', value: true }
 			});
 
 			const dialect = options.sqlite === 'turso' ? 'turso' : options.database;

packages/addons/eslint/index.ts

@@ -7,7 +7,6 @@ import {
 	functions,
 	imports,
 	object,
-	type AstKinds,
 	type AstTypes
 } from '@sveltejs/cli-core/js';
 import { parseJson, parseScript } from '@sveltejs/cli-core/parsers';
@@ -55,7 +54,7 @@ export default defineAddon({
 			const { ast, generateCode } = parseScript(content);
 
 			const eslintConfigs: Array<
-				AstKinds.ExpressionKind | AstTypes.SpreadElement | AstTypes.ObjectExpression
+				AstTypes.Expression | AstTypes.SpreadElement | AstTypes.ObjectExpression
 			> = [];
 
 			const gitIgnorePathStatement = common.statementFromString(

packages/addons/lucia/index.ts

@@ -55,17 +55,17 @@
 
 		sv.file(`drizzle.config.${ext}`, (content) => {
 			const { ast, generateCode } = parseScript(content);
-			const isProp = (name: string, node: AstTypes.ObjectProperty) =>
+			const isProp = (name: string, node: AstTypes.Property) =>
 				node.key.type === 'Identifier' && node.key.name === name;
 
 			// prettier-ignore
-			Walker.walk(ast as AstTypes.ASTNode, {}, {
-				ObjectProperty(node) {
-					if (isProp('dialect', node) && node.value.type === 'StringLiteral') {
+			Walker.walk(ast as AstTypes.Node, {}, {
+				Property(node) {
+					if (isProp('dialect', node) && node.value.type === 'Literal' && typeof node.value.type === 'string') {
 						drizzleDialect = node.value.value as Dialect;
 					}
-					if (isProp('schema', node) && node.value.type === 'StringLiteral') {
-						schemaPath = node.value.value;
+					if (isProp('schema', node) && node.value.type === 'Literal' && typeof node.value.type === 'string') {
+						schemaPath = node.value.value as string;
 					}
 				}
 			})
@@ -335,7 +335,7 @@
 		});
 
 		if (typescript) {
 			sv.file('src/app.d.ts', (content) => {
 				const { ast, generateCode } = parseScript(content);
 
 				const locals = js.kit.addGlobalAppInterface(ast, 'Locals');
@@ -601,13 +601,14 @@
 			type: 'Identifier',
 			name
 		},
+		computed: false,
 		typeAnnotation: {
 			type: 'TSTypeAnnotation',
 			typeAnnotation: {
 				type: 'TSIndexedAccessType',
 				objectType: {
 					type: 'TSImportType',
-					argument: { type: 'StringLiteral', value: '$lib/server/auth' },
+					argument: { type: 'Literal', value: '$lib/server/auth' },
 					qualifier: {
 						type: 'Identifier',
 						name: 'SessionValidationResult'
@@ -616,7 +617,7 @@
 				indexType: {
 					type: 'TSLiteralType',
 					literal: {
-						type: 'StringLiteral',
+						type: 'Literal',
 						value: name
 					}
 				}
@@ -649,7 +650,7 @@
 		};`;
 }
 
-function getCallExpression(ast: AstTypes.ASTNode): AstTypes.CallExpression | undefined {
+function getCallExpression(ast: AstTypes.Node): AstTypes.CallExpression | undefined {
 	let callExpression;
 
 	// prettier-ignore

packages/addons/sveltekit-adapter/index.ts

@@ -70,6 +70,9 @@ export default defineAddon({
 			if (adapterImportDecl) {
 				// replaces the import's source with the new adapter
 				adapterImportDecl.source.value = adapter.package;
+				// reset raw value, so that the string is re-generated
+				adapterImportDecl.source.raw = undefined;
+
 				adapterName = adapterImportDecl.specifiers?.find((s) => s.type === 'ImportDefaultSpecifier')
 					?.local?.name as string;
 			} else {
@@ -78,16 +81,15 @@ export default defineAddon({
 
 			const { value: config } = exports.defaultExport(ast, object.createEmpty());
 			const kitConfig = config.properties.find(
-				(p) => p.type === 'ObjectProperty' && p.key.type === 'Identifier' && p.key.name === 'kit'
-			) as AstTypes.ObjectProperty | undefined;
+				(p) => p.type === 'Property' && p.key.type === 'Identifier' && p.key.name === 'kit'
+			) as AstTypes.Property | undefined;
 
 			if (kitConfig && kitConfig.value.type === 'ObjectExpression') {
 				const adapterProp = kitConfig.value.properties.find(
-					(p) =>
-						p.type === 'ObjectProperty' && p.key.type === 'Identifier' && p.key.name === 'adapter'
+					(p) => p.type === 'Property' && p.key.type === 'Identifier' && p.key.name === 'adapter'
 				);
 				if (adapterProp) {
-					adapterProp.comments = [];
+					adapterProp.leadingComments = [];
 				}
 
 				// only overrides the `adapter` property so we can reset it's args

packages/ast-tooling/index.ts

@@ -1,8 +1,5 @@
-import { parse as tsParse } from 'recast/parsers/typescript.js';
-import { parse as recastParse, print as recastPrint, type Options as RecastOptions } from 'recast';
 import { Document, Element, type ChildNode } from 'domhandler';
 import { ElementType, parseDocument } from 'htmlparser2';
-import { removeElement, textContent } from 'domutils';
 import serializeDom from 'dom-serializer';
 import {
 	Root as CssAst,
@@ -15,8 +12,10 @@ import {
 } from 'postcss';
 import * as fleece from 'silver-fleece';
 import * as Walker from 'zimmerframe';
-import type { namedTypes as AstTypes } from 'ast-types';
-import type * as AstKinds from 'ast-types/gen/kinds';
+import type { TsEstree } from './ts-estree.ts';
+import { print as esrapPrint } from 'esrap';
+import * as acorn from 'acorn';
+import { tsPlugin } from 'acorn-typescript';
 
 /**
  * Most of the AST tooling is pretty big in bundle size and bundling takes forever.
@@ -48,34 +47,72 @@ export type {
 	ChildNode as HtmlChildNode,
 
 	// js
-	AstTypes,
-	AstKinds,
+	TsEstree as AstTypes,
 
 	//css
 	CssChildNode
 };
 
-export function parseScript(content: string): AstTypes.Program {
-	const recastOutput: { program: AstTypes.Program } = recastParse(content, {
-		parser: {
-			parse: tsParse
+export function parseScript(content: string): TsEstree.Program {
+	const comments: any[] = [];
+
+	// @ts-expect-error
+	const acornTs = acorn.Parser.extend(tsPlugin({ allowSatisfies: true }));
+
+	const ast = acornTs.parse(content, {
+		ecmaVersion: 'latest',
+		sourceType: 'module',
+		locations: true,
+		onComment: (block, value, start, end) => {
+			if (block && /\n/.test(value)) {
+				let a = start;
+				while (a > 0 && content[a - 1] !== '\n') a -= 1;
+
+				let b = a;
+				while (/[ \t]/.test(content[b])) b += 1;
+
+				const indentation = content.slice(a, b);
+				value = value.replace(new RegExp(`^${indentation}`, 'gm'), '');
+			}
+
+			comments.push({ type: block ? 'Block' : 'Line', value, start, end });
 		}
 	});
 
-	return recastOutput.program;
-}
+	Walker.walk(ast, null, {
+		_(node, { next }) {
+			const commentNode /** @type {import('../../src/types').NodeWithComments} */ =
+				/** @type {any} */ node;
+			let comment;
 
-export function serializeScript(ast: AstTypes.ASTNode, previousContent?: string): string {
-	let options: RecastOptions | undefined;
-	if (!previousContent) {
-		// provide sensible defaults if we generate a new file
-		options = {
-			quote: 'single',
-			useTabs: true
-		};
-	}
+			while (comments[0] && comments[0].start < node.start) {
+				comment = comments.shift();
+				// @ts-expect-error
+				(commentNode.leadingComments ||= []).push(comment);
+			}
+
+			next();
+
+			if (comments[0]) {
+				const slice = content.slice(node.end, comments[0].start);
+
+				if (/^[,) \t]*$/.test(slice)) {
+					// @ts-expect-error
+					commentNode.trailingComments = [comments.shift()];
+				}
+			}
+		}
+	});
+
+	return ast as TsEstree.Program;
+}
 
-	return recastPrint(ast, options).code;
+export function serializeScript(ast: TsEstree.Node): string {
+	const { code } = esrapPrint(ast, {
+		indent: '\t',
+		quotes: 'single'
+	});
+	return code;
 }
 
 export function parseCss(content: string): CssAst {
@@ -117,41 +154,11 @@ export function stripAst<T>(node: T, propToRemove: string): T {
 }
 
 export type SvelteAst = {
-	jsAst: AstTypes.Program;
+	jsAst: TsEstree.Program;
 	htmlAst: Document;
 	cssAst: CssAst;
 };
 
-export function parseSvelte(content: string): SvelteAst {
-	const htmlAst = parseHtml(content);
-
-	let scriptTag, styleTag;
-	for (const node of htmlAst.childNodes) {
-		if (node.type === ElementType.Script) {
-			scriptTag = node;
-			removeElement(scriptTag);
-		} else if (node.type === ElementType.Style) {
-			styleTag = node;
-			removeElement(styleTag);
-		}
-	}
-
-	if (!scriptTag) {
-		scriptTag = new Element('script', {}, undefined, ElementType.ElementType.Script);
-	}
-	if (!styleTag) {
-		styleTag = new Element('style', {}, undefined, ElementType.ElementType.Style);
-	}
-
-	const css = textContent(styleTag);
-	const cssAst = parseCss(css);
-
-	const scriptValue = textContent(scriptTag);
-	const jsAst = parseScript(scriptValue);
-
-	return { jsAst, htmlAst, cssAst };
-}
-
 export function parseJson(content: string): any {
 	// some of the files we need to process contain comments. The default
 	// node JSON.parse fails parsing those comments.

packages/ast-tooling/package.json

@@ -24,14 +24,15 @@
 		}
 	},
 	"devDependencies": {
-		"@babel/parser": "^7.26.3",
-		"ast-types": "^0.16.1",
+		"@types/estree": "^1.0.6",
+		"acorn": "^8.14.0",
+		"acorn-typescript": "^1.4.13",
 		"dom-serializer": "^2.0.0",
 		"domhandler": "^5.0.3",
 		"domutils": "^3.1.0",
+		"esrap": "^1.4.2",
 		"htmlparser2": "^9.1.0",
 		"postcss": "^8.4.49",
-		"recast": "^0.23.9",
 		"silver-fleece": "^1.2.1",
 		"zimmerframe": "^1.1.2"
 	}