From 18ed5b67f92392d2325209a684788194268d426d Mon Sep 17 00:00:00 2001
From: Scott Wu <sw@scottwu.ca>
Date: Mon, 30 Mar 2026 17:11:35 +0800
Subject: [PATCH 1/8] .

---
 packages/sv-utils/src/tooling/transforms.ts |  18 +-
 packages/sv/src/addons/better-auth.ts       | 176 +++++++++-----------
 packages/sv/src/addons/common.ts            |  10 +-
 packages/sv/src/addons/drizzle.ts           | 176 ++++++++++----------
 packages/sv/src/addons/mcp.ts               |  19 +--
 packages/sv/src/addons/paraglide.ts         |   6 +-
 packages/sv/src/addons/sveltekit-adapter.ts |  39 ++---
 packages/sv/src/addons/tailwindcss.ts       |  24 ++-
 packages/sv/src/addons/vitest-addon.ts      |  15 +-
 9 files changed, 224 insertions(+), 259 deletions(-)

diff --git a/packages/sv-utils/src/tooling/transforms.ts b/packages/sv-utils/src/tooling/transforms.ts
index 82f92b0c9..9b71a2f11 100644
--- a/packages/sv-utils/src/tooling/transforms.ts
+++ b/packages/sv-utils/src/tooling/transforms.ts
@@ -69,7 +69,7 @@ export const transforms = {
 	 * Return `false` from the callback to abort - the original content is returned unchanged.
 	 */
 	script(
-		cb: (args: {
+		cb: (file: {
 			ast: TsEstree.Program;
 			comments: Comments;
 			content: string;
@@ -92,7 +92,7 @@ export const transforms = {
 	 * Return `false` from the callback to abort - the original content is returned unchanged.
 	 */
 	svelte(
-		cb: (args: {
+		cb: (file: {
 			ast: SvelteAst.Root;
 			content: string;
 			svelte: typeof svelteNs;
@@ -119,7 +119,7 @@ export const transforms = {
 	 */
 	svelteScript(
 		scriptOptions: { language: 'ts' | 'js' },
-		cb: (args: {
+		cb: (file: {
 			ast: RootWithInstance;
 			content: string;
 			svelte: typeof svelteNs;
@@ -148,7 +148,7 @@ export const transforms = {
 	 * Return `false` from the callback to abort - the original content is returned unchanged.
 	 */
 	css(
-		cb: (args: {
+		cb: (file: {
 			ast: Omit<SvelteAst.CSS.StyleSheetBase, 'attributes' | 'content'>;
 			content: string;
 			css: typeof cssNs;
@@ -170,7 +170,7 @@ export const transforms = {
 	 * Return `false` from the callback to abort - the original content is returned unchanged.
 	 */
 	json<T = any>(
-		cb: (args: { data: T; content: string; json: typeof jsonNs }) => void | false,
+		cb: (file: { data: T; content: string; json: typeof jsonNs }) => void | false,
 		options?: TransformOptions
 	): (content: string) => string {
 		return (content) => {
@@ -188,7 +188,7 @@ export const transforms = {
 	 * Return `false` from the callback to abort - the original content is returned unchanged.
 	 */
 	yaml(
-		cb: (args: { data: ReturnType<typeof parseYaml>['data']; content: string }) => void | false,
+		cb: (file: { data: ReturnType<typeof parseYaml>['data']; content: string }) => void | false,
 		options?: TransformOptions
 	): (content: string) => string {
 		return (content) => {
@@ -206,7 +206,7 @@ export const transforms = {
 	 * Return `false` from the callback to abort - the original content is returned unchanged.
 	 */
 	toml(
-		cb: (args: { data: TomlTable; content: string }) => void | false,
+		cb: (file: { data: TomlTable; content: string }) => void | false,
 		options?: TransformOptions
 	): (content: string) => string {
 		return (content) => {
@@ -224,7 +224,7 @@ export const transforms = {
 	 * Return `false` from the callback to abort - the original content is returned unchanged.
 	 */
 	html(
-		cb: (args: { ast: SvelteAst.Fragment; content: string; html: typeof htmlNs }) => void | false,
+		cb: (file: { ast: SvelteAst.Fragment; content: string; html: typeof htmlNs }) => void | false,
 		options?: TransformOptions
 	): (content: string) => string {
 		return (content) => {
@@ -243,7 +243,7 @@ export const transforms = {
 	 * Return the new content, or `false` to abort (original content is returned unchanged).
 	 */
 	text(
-		cb: (args: { content: string; text: typeof textNs }) => string | false
+		cb: (file: { content: string; text: typeof textNs }) => string | false
 	): (content: string) => string {
 		return (content) => {
 			const result = cb({ content, text: textNs });
diff --git a/packages/sv/src/addons/better-auth.ts b/packages/sv/src/addons/better-auth.ts
index 22094f2ec..4edd6240b 100644
--- a/packages/sv/src/addons/better-auth.ts
+++ b/packages/sv/src/addons/better-auth.ts
@@ -4,7 +4,6 @@ import {
 	Walker,
 	color,
 	dedent,
-	text,
 	transforms,
 	resolveCommand,
 	createPrinter
@@ -86,14 +85,8 @@ export default defineAddon({
 			})
 		);
 
-		sv.file(
-			'.env',
-			transforms.text(({ content }) => generateEnvFileContent(content, demoGithub, false))
-		);
-		sv.file(
-			'.env.example',
-			transforms.text(({ content }) => generateEnvFileContent(content, demoGithub, true))
-		);
+		sv.file('.env', generateEnvFileContent(demoGithub, false));
+		sv.file('.env.example', generateEnvFileContent(demoGithub, true));
 
 		sv.file(
 			`${directory.lib}/server/auth.${language}`,
@@ -296,11 +289,11 @@ export default defineAddon({
 
 			sv.file(
 				`${directory.kitRoutes}/demo/better-auth/login/+page.server.${language}`,
-				transforms.text(({ content }) => {
+				(content) => {
 					if (content) {
 						const filePath = `${directory.kitRoutes}/demo/better-auth/login/+page.server.${language}`;
 						log.warn(`Existing ${color.warning(filePath)} file. Could not update.`);
-						return false;
+						return content;
 					}
 
 					const [ts] = createPrinter(language === 'ts');
@@ -397,31 +390,29 @@ export default defineAddon({
 					export const actions${ts(': Actions')} = {${signInEmailAction}${signInSocialAction}
 					};
 				`;
-				})
+				}
 			);
 
-			sv.file(
-				`${directory.kitRoutes}/demo/better-auth/login/+page.svelte`,
-				transforms.text(({ content }) => {
-					if (content) {
-						const filePath = `${directory.kitRoutes}/demo/better-auth/login/+page.svelte`;
-						log.warn(`Existing ${color.warning(filePath)} file. Could not update.`);
-						return false;
-					}
+			sv.file(`${directory.kitRoutes}/demo/better-auth/login/+page.svelte`, (content) => {
+				if (content) {
+					const filePath = `${directory.kitRoutes}/demo/better-auth/login/+page.svelte`;
+					log.warn(`Existing ${color.warning(filePath)} file. Could not update.`);
+					return content;
+				}
 
-					const tailwind = dependencyVersion('@tailwindcss/vite') !== undefined;
-					const input = tailwind
-						? ' class="mt-1 px-3 py-2 bg-white border border-gray-300 rounded-md shadow-sm focus:outline-none focus:ring-2 focus:ring-blue-500 focus:border-blue-500"'
-						: '';
-					const btn = tailwind
-						? ' class="bg-blue-600 text-white px-4 py-2 rounded-md hover:bg-blue-700 transition"'
-						: '';
+				const tailwind = dependencyVersion('@tailwindcss/vite') !== undefined;
+				const input = tailwind
+					? ' class="mt-1 px-3 py-2 bg-white border border-gray-300 rounded-md shadow-sm focus:outline-none focus:ring-2 focus:ring-blue-500 focus:border-blue-500"'
+					: '';
+				const btn = tailwind
+					? ' class="bg-blue-600 text-white px-4 py-2 rounded-md hover:bg-blue-700 transition"'
+					: '';
 
-					const svelte5 = !!dependencyVersion('svelte')?.startsWith('5');
-					const [ts, s5] = createPrinter(language === 'ts', svelte5);
+				const svelte5 = !!dependencyVersion('svelte')?.startsWith('5');
+				const [ts, s5] = createPrinter(language === 'ts', svelte5);
 
-					const passwordForm = demoPassword
-						? `
+				const passwordForm = demoPassword
+					? `
 					<form method="post" action="?/signInEmail" use:enhance>
 						<label>
 							Email
@@ -439,23 +430,23 @@ export default defineAddon({
 						<button formaction="?/signUpEmail"${btn}>Register</button>
 					</form>
 					${tailwind ? `<p class="text-red-500">{form?.message ?? ''}</p>` : `<p style="color: red">{form?.message ?? ''}</p>`}`
-						: '';
+					: '';
 
-					const separator =
-						demoPassword && demoGithub
-							? `\n\n\t\t\t\t\t<hr ${tailwind ? 'class="my-4"' : ''} />\n`
-							: '';
+				const separator =
+					demoPassword && demoGithub
+						? `\n\n\t\t\t\t\t<hr ${tailwind ? 'class="my-4"' : ''} />\n`
+						: '';
 
-					const githubForm = demoGithub
-						? `
+				const githubForm = demoGithub
+					? `
 					<form method="post" action="?/signInSocial" use:enhance>
 						<input type="hidden" name="provider" value="github" />
 						<input type="hidden" name="callbackURL" value="/demo/better-auth" />
 						<button${btn}>Sign in with GitHub</button>
 					</form>`
-						: '';
+					: '';
 
-					return dedent`
+				return dedent`
 					<script ${ts("lang='ts'")}>
 						import { enhance } from '$app/forms';
 						${ts("import type { ActionData } from './$types';\n")}
@@ -464,21 +455,18 @@ export default defineAddon({
 
 					<h1>Login</h1>${passwordForm}${separator}${githubForm}
 				`;
-				})
-			);
+			});
 
-			sv.file(
-				`${directory.kitRoutes}/demo/better-auth/+page.server.${language}`,
-				transforms.text(({ content }) => {
-					if (content) {
-						const filePath = `${directory.kitRoutes}/demo/better-auth/+page.server.${language}`;
-						log.warn(`Existing ${color.warning(filePath)} file. Could not update.`);
-						return false;
-					}
+			sv.file(`${directory.kitRoutes}/demo/better-auth/+page.server.${language}`, (content) => {
+				if (content) {
+					const filePath = `${directory.kitRoutes}/demo/better-auth/+page.server.${language}`;
+					log.warn(`Existing ${color.warning(filePath)} file. Could not update.`);
+					return content;
+				}
 
-					const [ts] = createPrinter(language === 'ts');
-					const d1AuthLine = d1 ? '\n\t\t\t\t\t\t\tconst { auth } = event.locals;\n' : '';
-					return dedent`
+				const [ts] = createPrinter(language === 'ts');
+				const d1AuthLine = d1 ? '\n\t\t\t\t\t\t\tconst { auth } = event.locals;\n' : '';
+				return dedent`
 					import { redirect } from '@sveltejs/kit';
 					${ts("import type { Actions } from './$types';")}
 					${ts("import type { PageServerLoad } from './$types';")}
@@ -500,25 +488,22 @@ export default defineAddon({
 						}
 					};
 				`;
-				})
-			);
+			});
 
-			sv.file(
-				`${directory.kitRoutes}/demo/better-auth/+page.svelte`,
-				transforms.text(({ content }) => {
-					if (content) {
-						const filePath = `${directory.kitRoutes}/demo/better-auth/+page.svelte`;
-						log.warn(`Existing ${color.warning(filePath)} file. Could not update.`);
-						return false;
-					}
+			sv.file(`${directory.kitRoutes}/demo/better-auth/+page.svelte`, (content) => {
+				if (content) {
+					const filePath = `${directory.kitRoutes}/demo/better-auth/+page.svelte`;
+					log.warn(`Existing ${color.warning(filePath)} file. Could not update.`);
+					return content;
+				}
 
-					const tailwind = dependencyVersion('@tailwindcss/vite') !== undefined;
-					const twBtnClasses =
-						'class="bg-blue-600 text-white px-4 py-2 rounded-md hover:bg-blue-700 transition"';
+				const tailwind = dependencyVersion('@tailwindcss/vite') !== undefined;
+				const twBtnClasses =
+					'class="bg-blue-600 text-white px-4 py-2 rounded-md hover:bg-blue-700 transition"';
 
-					const svelte5 = !!dependencyVersion('svelte')?.startsWith('5');
-					const [ts, s5] = createPrinter(language === 'ts', svelte5);
-					return dedent`
+				const svelte5 = !!dependencyVersion('svelte')?.startsWith('5');
+				const [ts, s5] = createPrinter(language === 'ts', svelte5);
+				return dedent`
 					<script ${ts("lang='ts'")}>
 						import { enhance } from '$app/forms';
 						${ts("import type { PageServerData } from './$types';\n")}
@@ -531,8 +516,7 @@ export default defineAddon({
 						<button ${tailwind ? twBtnClasses : ''}>Sign out</button>
 					</form>
 				`;
-				})
-			);
+			});
 		}
 	},
 
@@ -559,28 +543,32 @@ export default defineAddon({
 	}
 });
 
-function generateEnvFileContent(content: string, demoGithub: boolean, isExample: boolean) {
-	content = text.upsert(content, 'ORIGIN', {
-		value: isExample ? `""` : `"http://localhost:5173"`,
-		separator: true
-	});
-	content = text.upsert(content, 'BETTER_AUTH_SECRET', {
-		value: isExample ? `""` : `"${crypto.randomUUID()}"`,
-		comment: [
-			'Better Auth',
-			'For production use 32 characters and generated with high entropy',
-			'https://www.better-auth.com/docs/installation'
-		],
-		separator: true
-	});
-
-	if (demoGithub) {
-		content = text.upsert(content, 'GITHUB_CLIENT_ID', {
-			value: `""`,
-			comment: 'GitHub OAuth\n# https://www.better-auth.com/docs/authentication/github'
+const generateEnvFileContent: (
+	demoGithub: boolean,
+	isExample: boolean
+) => (content: string) => string = (demoGithub, isExample) =>
+	transforms.text(({ content, text }) => {
+		content = text.upsert(content, 'ORIGIN', {
+			value: isExample ? `""` : `"http://localhost:5173"`,
+			separator: true
+		});
+		content = text.upsert(content, 'BETTER_AUTH_SECRET', {
+			value: isExample ? `""` : `"${crypto.randomUUID()}"`,
+			comment: [
+				'Better Auth',
+				'For production use 32 characters and generated with high entropy',
+				'https://www.better-auth.com/docs/installation'
+			],
+			separator: true
 		});
-		content = text.upsert(content, 'GITHUB_CLIENT_SECRET', { value: `""` });
-	}
 
-	return content;
-}
+		if (demoGithub) {
+			content = text.upsert(content, 'GITHUB_CLIENT_ID', {
+				value: `""`,
+				comment: 'GitHub OAuth\n# https://www.better-auth.com/docs/authentication/github'
+			});
+			content = text.upsert(content, 'GITHUB_CLIENT_SECRET', { value: `""` });
+		}
+
+		return content;
+	});
diff --git a/packages/sv/src/addons/common.ts b/packages/sv/src/addons/common.ts
index 0b34b3a7f..f217fb4fa 100644
--- a/packages/sv/src/addons/common.ts
+++ b/packages/sv/src/addons/common.ts
@@ -57,8 +57,9 @@ export const addEslintConfigPrettier = transforms.script(({ ast, js }) => {
 	}
 });
 
-export function addToDemoPage(path: string, language: 'ts' | 'js'): (content: string) => string {
-	return transforms.svelteScript({ language }, ({ ast, js, svelte }) => {
+type AddToDemoPage = (path: string, language: 'ts' | 'js') => (content: string) => string;
+export const addToDemoPage: AddToDemoPage = (path, language) =>
+	transforms.svelteScript({ language }, ({ ast, js, svelte }) => {
 		for (const node of ast.fragment.nodes) {
 			if (node.type === 'RegularElement') {
 				const hrefAttribute = node.attributes.find(
@@ -80,11 +81,8 @@ export function addToDemoPage(path: string, language: 'ts' | 'js'): (content: st
 
 		js.imports.addNamed(ast.instance.content, { imports: ['resolve'], from: '$app/paths' });
 
-		svelte.addFragment(ast, `<a href={resolve('/demo/${path}')}>${path}</a>`, {
-			mode: 'prepend'
-		});
+		svelte.addFragment(ast, `<a href={resolve('/demo/${path}')}>${path}</a>`, { mode: 'prepend' });
 	});
-}
 
 /**
  * Returns the corresponding `@types/node` version for the version of Node.js running in the current process.
diff --git a/packages/sv/src/addons/drizzle.ts b/packages/sv/src/addons/drizzle.ts
index 3b12ce3f4..0b2f6b51d 100644
--- a/packages/sv/src/addons/drizzle.ts
+++ b/packages/sv/src/addons/drizzle.ts
@@ -1,4 +1,4 @@
-import { color, dedent, text, transforms, resolveCommand, fileExists } from '@sveltejs/sv-utils';
+import { color, dedent, transforms, resolveCommand, fileExists } from '@sveltejs/sv-utils';
 import crypto from 'node:crypto';
 import fs from 'node:fs';
 import path from 'node:path';
@@ -122,14 +122,8 @@ export default defineAddon({
 		if (options.sqlite === 'libsql' || options.sqlite === 'turso')
 			sv.devDependency('@libsql/client', '^0.17.0');
 
-		sv.file(
-			'.env',
-			transforms.text(({ content }) => generateEnvFileContent(content, options, false))
-		);
-		sv.file(
-			'.env.example',
-			transforms.text(({ content }) => generateEnvFileContent(content, options, true))
-		);
+		sv.file('.env', generateEnvFileContent(options, false));
+		sv.file('.env.example', generateEnvFileContent(options, true));
 
 		if (options.docker && (options.mysql === 'mysql2' || options.postgresql === 'postgres.js')) {
 			const composeFileOptions = ['docker-compose.yml', 'docker-compose.yaml', 'compose.yaml'];
@@ -140,23 +134,21 @@ export default defineAddon({
 			}
 			if (composeFile === '') throw new Error('unreachable state...');
 
-			sv.file(
-				composeFile,
-				transforms.text(({ content }) => {
-					// if the file already exists, don't modify it
-					// (in the future, we could add some tooling for modifying yaml)
-					if (content.length > 0) return false;
-
-					const imageName = options.database === 'mysql' ? 'mysql' : 'postgres';
-					const port = PORTS[options.database];
-
-					const USER = 'root';
-					const PASSWORD = 'mysecretpassword';
-					const DB_NAME = 'local';
-
-					let dbSpecificContent = '';
-					if (options.mysql === 'mysql2') {
-						dbSpecificContent = `
+			sv.file(composeFile, (content) => {
+				// if the file already exists, don't modify it
+				// (in the future, we could add some tooling for modifying yaml)
+				if (content.length > 0) return content;
+
+				const imageName = options.database === 'mysql' ? 'mysql' : 'postgres';
+				const port = PORTS[options.database];
+
+				const USER = 'root';
+				const PASSWORD = 'mysecretpassword';
+				const DB_NAME = 'local';
+
+				let dbSpecificContent = '';
+				if (options.mysql === 'mysql2') {
+					dbSpecificContent = `
                       MYSQL_ROOT_PASSWORD: ${PASSWORD}
                       MYSQL_DATABASE: ${DB_NAME}
                     volumes:
@@ -164,9 +156,9 @@ export default defineAddon({
                 volumes:
                   mysqldata:
                 `;
-					}
-					if (options.postgresql === 'postgres.js') {
-						dbSpecificContent = `
+				}
+				if (options.postgresql === 'postgres.js') {
+					dbSpecificContent = `
                       POSTGRES_USER: ${USER}
                       POSTGRES_PASSWORD: ${PASSWORD}
                       POSTGRES_DB: ${DB_NAME}
@@ -175,9 +167,9 @@ export default defineAddon({
                 volumes:
                   pgdata:
                 `;
-					}
+				}
 
-					return dedent`
+				return dedent`
                 services:
                   db:
                     image: ${imageName}
@@ -186,8 +178,7 @@ export default defineAddon({
                       - ${port}:${port}
                     environment: ${dbSpecificContent}
                 `;
-				})
-			);
+			});
 		}
 
 		sv.file(
@@ -205,14 +196,14 @@ export default defineAddon({
 		if (hasPrettier) {
 			sv.file(
 				file.prettierignore,
-				transforms.text(({ content }) => text.upsert(content, '/drizzle/'))
+				transforms.text(({ content, text }) => text.upsert(content, '/drizzle/'))
 			);
 		}
 
 		if (options.database === 'sqlite') {
 			sv.file(
 				file.gitignore,
-				transforms.text(({ content }) => {
+				transforms.text(({ content, text }) => {
 					if (content.length === 0) return false;
 					return text.upsert(content, '*.db', { comment: 'SQLite' });
 				})
@@ -514,68 +505,69 @@ export default defineAddon({
 	}
 });
 
-function generateEnvFileContent(
-	content: string,
+type GenerateEnvFileContent = (
 	opts: OptionValues<typeof options>,
 	isExample: boolean
-) {
-	const DB_URL_KEY = 'DATABASE_URL';
-
-	if (opts.database === 'd1') {
-		content = text.upsert(content, 'CLOUDFLARE_ACCOUNT_ID', {
-			value: '""',
-			comment: ['Cloudflare D1'],
-			separator: true
-		});
-		content = text.upsert(content, 'CLOUDFLARE_DATABASE_ID', { value: '""' });
-		content = text.upsert(content, 'CLOUDFLARE_D1_TOKEN', { value: '""' });
-		return content;
-	}
+) => (content: string) => string;
+const generateEnvFileContent: GenerateEnvFileContent = (opts, isExample) =>
+	transforms.text(({ content, text }) => {
+		const DB_URL_KEY = 'DATABASE_URL';
+
+		if (opts.database === 'd1') {
+			content = text.upsert(content, 'CLOUDFLARE_ACCOUNT_ID', {
+				value: '""',
+				comment: ['Cloudflare D1'],
+				separator: true
+			});
+			content = text.upsert(content, 'CLOUDFLARE_DATABASE_ID', { value: '""' });
+			content = text.upsert(content, 'CLOUDFLARE_D1_TOKEN', { value: '""' });
+			return content;
+		}
 
-	// Calculate value and comment based on database options
-	let value: string;
-	const comment: NonNullable<Parameters<typeof text.upsert>[2]>['comment'] = ['Drizzle'];
-
-	if (opts.docker) {
-		const protocol = opts.database === 'mysql' ? 'mysql' : 'postgres';
-		const port = PORTS[opts.database];
-		value = `"${protocol}://root:mysecretpassword@localhost:${port}/local"`;
-	} else if (opts.sqlite === 'better-sqlite3' || opts.sqlite === 'libsql') {
-		value = opts.sqlite === 'libsql' ? 'file:local.db' : 'local.db';
-	} else if (opts.sqlite === 'turso') {
-		if (isExample) {
-			value = '"libsql://db-name-user.turso.io"';
-			comment.push(
-				'Replace with your DB credentials!',
-				{ text: 'A local DB can also be used in dev as well', mode: 'append' },
-				{ text: `${DB_URL_KEY}="file:local.db"`, mode: 'append' }
-			);
+		// Calculate value and comment based on database options
+		let value: string;
+		const comment: NonNullable<Parameters<typeof text.upsert>[2]>['comment'] = ['Drizzle'];
+
+		if (opts.docker) {
+			const protocol = opts.database === 'mysql' ? 'mysql' : 'postgres';
+			const port = PORTS[opts.database];
+			value = `"${protocol}://root:mysecretpassword@localhost:${port}/local"`;
+		} else if (opts.sqlite === 'better-sqlite3' || opts.sqlite === 'libsql') {
+			value = opts.sqlite === 'libsql' ? 'file:local.db' : 'local.db';
+		} else if (opts.sqlite === 'turso') {
+			if (isExample) {
+				value = '"libsql://db-name-user.turso.io"';
+				comment.push(
+					'Replace with your DB credentials!',
+					{ text: 'A local DB can also be used in dev as well', mode: 'append' },
+					{ text: `${DB_URL_KEY}="file:local.db"`, mode: 'append' }
+				);
+			} else {
+				value = '"file:local.db"';
+				comment.push(
+					'Replace with your DB credentials!',
+					`${DB_URL_KEY}="libsql://db-name-user.turso.io"`,
+					'A local DB can also be used in dev as well'
+				);
+			}
+		} else if (opts.database === 'mysql') {
+			value = '"mysql://user:password@host:port/db-name"';
+			comment.push('Replace with your DB credentials!');
+		} else if (opts.database === 'postgresql') {
+			value = '"postgres://user:password@host:port/db-name"';
+			comment.push('Replace with your DB credentials!');
 		} else {
-			value = '"file:local.db"';
-			comment.push(
-				'Replace with your DB credentials!',
-				`${DB_URL_KEY}="libsql://db-name-user.turso.io"`,
-				'A local DB can also be used in dev as well'
-			);
+			value = '';
 		}
-	} else if (opts.database === 'mysql') {
-		value = '"mysql://user:password@host:port/db-name"';
-		comment.push('Replace with your DB credentials!');
-	} else if (opts.database === 'postgresql') {
-		value = '"postgres://user:password@host:port/db-name"';
-		comment.push('Replace with your DB credentials!');
-	} else {
-		value = '';
-	}
 
-	content = text.upsert(content, DB_URL_KEY, { value, comment, separator: true });
+		content = text.upsert(content, DB_URL_KEY, { value, comment, separator: true });
 
-	// Turso requires an auth token
-	if (opts.sqlite === 'turso') {
-		content = text.upsert(content, 'DATABASE_AUTH_TOKEN', {
-			value: isExample ? `""` : `"${crypto.randomUUID()}"`
-		});
-	}
+		// Turso requires an auth token
+		if (opts.sqlite === 'turso') {
+			content = text.upsert(content, 'DATABASE_AUTH_TOKEN', {
+				value: isExample ? `""` : `"${crypto.randomUUID()}"`
+			});
+		}
 
-	return content;
-}
+		return content;
+	});
diff --git a/packages/sv/src/addons/mcp.ts b/packages/sv/src/addons/mcp.ts
index c232beb03..e83a4659c 100644
--- a/packages/sv/src/addons/mcp.ts
+++ b/packages/sv/src/addons/mcp.ts
@@ -140,17 +140,14 @@ export default defineAddon({
 
 			// We only add the agent file if it's not already added
 			if (!filesAdded.includes(agentPath)) {
-				sv.file(
-					agentPath,
-					transforms.text(({ content }) => {
-						if (content) {
-							filesExistingAlready.push(agentPath);
-							return false;
-						}
-						filesAdded.push(agentPath);
-						return agentFile?.contents ?? '';
-					})
-				);
+				sv.file(agentPath, (content) => {
+					if (content) {
+						filesExistingAlready.push(agentPath);
+						return content;
+					}
+					filesAdded.push(agentPath);
+					return agentFile?.contents ?? '';
+				});
 			}
 
 			sv.file(
diff --git a/packages/sv/src/addons/paraglide.ts b/packages/sv/src/addons/paraglide.ts
index 77440d1a4..8d288183f 100644
--- a/packages/sv/src/addons/paraglide.ts
+++ b/packages/sv/src/addons/paraglide.ts
@@ -1,5 +1,5 @@
 import { log } from '@clack/prompts';
-import { color, type SvelteAst, text, transforms } from '@sveltejs/sv-utils';
+import { color, type SvelteAst, transforms } from '@sveltejs/sv-utils';
 import { defineAddon, defineAddonOptions } from '../core/config.ts';
 import { addToDemoPage } from './common.ts';
 
@@ -153,7 +153,7 @@ export default defineAddon({
 					log.warn(
 						"Could not find <html> node in app.html. You'll need to add the language placeholder manually"
 					);
-					return;
+					return false;
 				}
 				html.addAttribute(htmlNode, 'lang', '%paraglide.lang%');
 				html.addAttribute(htmlNode, 'dir', '%paraglide.dir%');
@@ -162,7 +162,7 @@ export default defineAddon({
 
 		sv.file(
 			file.gitignore,
-			transforms.text(({ content }) => {
+			transforms.text(({ content, text }) => {
 				if (!content) return false;
 
 				content = text.upsert(content, paraglideOutDir, { comment: 'Paraglide' });
diff --git a/packages/sv/src/addons/sveltekit-adapter.ts b/packages/sv/src/addons/sveltekit-adapter.ts
index 5d31f7bf4..e4cd55a9e 100644
--- a/packages/sv/src/addons/sveltekit-adapter.ts
+++ b/packages/sv/src/addons/sveltekit-adapter.ts
@@ -5,7 +5,8 @@ import {
 	transforms,
 	fileExists,
 	getPackageJson,
-	sanitizeName
+	sanitizeName,
+	commonFilePaths
 } from '@sveltejs/sv-utils';
 import { defineAddon, defineAddonOptions } from '../core/config.ts';
 
@@ -78,8 +79,8 @@ export default defineAddon({
 			file.svelteConfig,
 			transforms.script(({ ast, comments, js }) => {
 				// finds any existing adapter's import declaration
-				const importDecls = ast.body.filter((n) => n.type === 'ImportDeclaration');
-				const adapterImportDecl = importDecls.find(
+				const imports = ast.body.filter((n) => n.type === 'ImportDeclaration');
+				const adapterImports = imports.find(
 					(importDecl) =>
 						typeof importDecl.source.value === 'string' &&
 						importDecl.source.value.startsWith('@sveltejs/adapter-') &&
@@ -87,31 +88,26 @@ export default defineAddon({
 				);
 
 				let adapterName = 'adapter';
-				if (adapterImportDecl) {
+				if (adapterImports) {
 					// replaces the import's source with the new adapter
-					adapterImportDecl.source.value = adapter.package;
+					adapterImports.source.value = adapter.package;
 					// reset raw value, so that the string is re-generated
-					adapterImportDecl.source.raw = undefined;
+					adapterImports.source.raw = undefined;
 
-					adapterName = adapterImportDecl.specifiers?.find(
+					const defaultSpecifier = adapterImports.specifiers?.find(
 						(s) => s.type === 'ImportDefaultSpecifier'
-					)?.local?.name as string;
+					);
+					adapterName = defaultSpecifier!.local.name;
 				} else {
 					js.imports.addDefault(ast, { from: adapter.package, as: adapterName });
 				}
 
-				const { value: config } = js.exports.createDefault(ast, {
-					fallback: js.object.create({})
-				});
+				const { value: config } = js.exports.createDefault(ast, { fallback: js.object.create({}) });
 
 				// override the adapter property
 				js.object.overrideProperties(config, {
 					kit: {
-						adapter: js.functions.createCall({
-							name: adapterName,
-							args: [],
-							useIdentifiers: true
-						})
+						adapter: js.functions.createCall({ name: adapterName, args: [], useIdentifiers: true })
 					}
 				});
 
@@ -175,13 +171,14 @@ export default defineAddon({
 				}
 			};
 
-			sv.file(`wrangler.${ext}`, (content) =>
+			sv.file(
+				`wrangler.${ext}`,
 				ext === 'toml'
-					? transforms.toml(({ data }) => applyWranglerConfig(data))(content)
-					: transforms.json(({ data }) => applyWranglerConfig(data))(content)
+					? transforms.toml(({ data }) => applyWranglerConfig(data))
+					: transforms.json(({ data }) => applyWranglerConfig(data))
 			);
 
-			const jsconfig = fileExists(cwd, 'jsconfig.json');
+			const jsconfig = fileExists(cwd, commonFilePaths.jsconfig);
 			const typeChecked = language === 'ts' || jsconfig;
 
 			if (typeChecked) {
@@ -205,7 +202,7 @@ export default defineAddon({
 
 				// Add Cloudflare generated types to tsconfig
 				sv.file(
-					`${jsconfig ? 'jsconfig' : 'tsconfig'}.json`,
+					jsconfig ? commonFilePaths.jsconfig : commonFilePaths.tsconfig,
 					transforms.json(({ data }) => {
 						data.compilerOptions ??= {};
 						data.compilerOptions.types ??= [];
diff --git a/packages/sv/src/addons/tailwindcss.ts b/packages/sv/src/addons/tailwindcss.ts
index 3d88a0fc9..5dd26ce2c 100644
--- a/packages/sv/src/addons/tailwindcss.ts
+++ b/packages/sv/src/addons/tailwindcss.ts
@@ -79,16 +79,7 @@ export default defineAddon({
 			})
 		);
 
-		if (!isKit) {
-			const appSvelte = `${directory.src}/App.svelte`;
-			const stylesheetRelative = file.getRelative({ from: appSvelte, to: file.stylesheet });
-			sv.file(
-				appSvelte,
-				transforms.svelteScript({ language }, ({ ast, js }) => {
-					js.imports.addEmpty(ast.instance.content, { from: stylesheetRelative });
-				})
-			);
-		} else {
+		if (isKit) {
 			const layoutSvelte = `${directory.kitRoutes}/+layout.svelte`;
 			const stylesheetRelative = file.getRelative({ from: layoutSvelte, to: file.stylesheet });
 			sv.file(
@@ -99,12 +90,19 @@ export default defineAddon({
 					if (ast.fragment.nodes.length === 0) {
 						const svelteVersion = dependencyVersion('svelte');
 						if (!svelteVersion) throw new Error('Failed to determine svelte version');
-						svelte.addSlot(ast, {
-							svelteVersion
-						});
+						svelte.addSlot(ast, { svelteVersion });
 					}
 				})
 			);
+		} else {
+			const appSvelte = `${directory.src}/App.svelte`;
+			const stylesheetRelative = file.getRelative({ from: appSvelte, to: file.stylesheet });
+			sv.file(
+				appSvelte,
+				transforms.svelteScript({ language }, ({ ast, js }) => {
+					js.imports.addEmpty(ast.instance.content, { from: stylesheetRelative });
+				})
+			);
 		}
 
 		sv.file(
diff --git a/packages/sv/src/addons/vitest-addon.ts b/packages/sv/src/addons/vitest-addon.ts
index 548f61ae3..fdd211226 100644
--- a/packages/sv/src/addons/vitest-addon.ts
+++ b/packages/sv/src/addons/vitest-addon.ts
@@ -1,4 +1,4 @@
-import { color, dedent, transforms } from '@sveltejs/sv-utils';
+import { color, createPrinter, dedent, transforms } from '@sveltejs/sv-utils';
 import { defineAddon, defineAddonOptions } from '../core/config.ts';
 
 const options = defineAddonOptions()
@@ -45,14 +45,12 @@ export default defineAddon({
 			transforms.json(({ data, json }) => {
 				json.packageScriptsUpsert(data, 'test:unit', 'vitest');
 				// we use `--run` so that vitest doesn't run in watch mode when running `npm run test`
-				json.packageScriptsUpsert(data, 'test', 'npm run test:unit -- --run', {
-					mode: 'prepend'
-				});
+				json.packageScriptsUpsert(data, 'test', 'npm run test:unit -- --run', { mode: 'prepend' });
 			})
 		);
 
 		const examplesDir = `${directory.lib}/vitest-examples`;
-		const typed = language === 'ts';
+		const [ts] = createPrinter(language === 'ts');
 
 		if (unitTesting || componentTesting) {
 			sv.file(
@@ -61,7 +59,7 @@ export default defineAddon({
 					if (content) return false;
 
 					return dedent`
-						export function greet(${typed ? 'name: string' : 'name'})${typed ? ': string' : ''} {
+						export function greet(name${ts(': string')})${ts(': string')} {
 							return 'Hello, ' + name + '!';
 						}
 					`;
@@ -180,10 +178,7 @@ export default defineAddon({
 
 				// Manage imports
 				if (componentTesting)
-					js.imports.addNamed(ast, {
-						imports: ['playwright'],
-						from: '@vitest/browser-playwright'
-					});
+					js.imports.addNamed(ast, { imports: ['playwright'], from: '@vitest/browser-playwright' });
 				const importName = 'defineConfig';
 				const { statement, alias } = js.imports.find(ast, { name: importName, from: 'vite' });
 				if (statement) {

From a741e764b3af51514bcff82b1983fdc15a5e2198 Mon Sep 17 00:00:00 2001
From: Scott Wu <sw@scottwu.ca>
Date: Mon, 30 Mar 2026 17:42:25 +0800
Subject: [PATCH 2/8] add a type helper

---
 packages/sv-utils/src/index.ts              |  1 +
 packages/sv-utils/src/tooling/transforms.ts |  2 ++
 packages/sv/src/addons/better-auth.ts       | 14 ++++++--------
 packages/sv/src/addons/common.ts            |  4 ++--
 packages/sv/src/addons/drizzle.ts           | 20 ++++++++++++--------
 5 files changed, 23 insertions(+), 18 deletions(-)

diff --git a/packages/sv-utils/src/index.ts b/packages/sv-utils/src/index.ts
index 00288175d..ad6df04f4 100644
--- a/packages/sv-utils/src/index.ts
+++ b/packages/sv-utils/src/index.ts
@@ -82,3 +82,4 @@ export { color } from './color.ts';
 
 // Types
 export type { Comments, AstTypes, SvelteAst } from './tooling/index.ts';
+export type { TransformFn } from './tooling/transforms.ts';
diff --git a/packages/sv-utils/src/tooling/transforms.ts b/packages/sv-utils/src/tooling/transforms.ts
index 9b71a2f11..1de419038 100644
--- a/packages/sv-utils/src/tooling/transforms.ts
+++ b/packages/sv-utils/src/tooling/transforms.ts
@@ -18,6 +18,8 @@ import { type RootWithInstance, ensureScript } from './svelte/index.ts';
 import * as svelteNs from './svelte/index.ts';
 import * as textNs from './text.ts';
 
+export type TransformFn = (content: string) => string;
+
 type TransformOptions = {
 	/** Called when parsing fails. If provided, the original content is returned unchanged. */
 	onParseError?: (error: unknown) => void;
diff --git a/packages/sv/src/addons/better-auth.ts b/packages/sv/src/addons/better-auth.ts
index 4edd6240b..6e8895fa9 100644
--- a/packages/sv/src/addons/better-auth.ts
+++ b/packages/sv/src/addons/better-auth.ts
@@ -6,7 +6,8 @@ import {
 	dedent,
 	transforms,
 	resolveCommand,
-	createPrinter
+	createPrinter,
+	type TransformFn
 } from '@sveltejs/sv-utils';
 import crypto from 'node:crypto';
 import { defineAddon, defineAddonOptions } from '../core/config.ts';
@@ -85,8 +86,8 @@ export default defineAddon({
 			})
 		);
 
-		sv.file('.env', generateEnvFileContent(demoGithub, false));
-		sv.file('.env.example', generateEnvFileContent(demoGithub, true));
+		sv.file('.env', generateEnv(demoGithub, false));
+		sv.file('.env.example', generateEnv(demoGithub, true));
 
 		sv.file(
 			`${directory.lib}/server/auth.${language}`,
@@ -542,11 +543,8 @@ export default defineAddon({
 		return steps;
 	}
 });
-
-const generateEnvFileContent: (
-	demoGithub: boolean,
-	isExample: boolean
-) => (content: string) => string = (demoGithub, isExample) =>
+type GenerateEnv = (demoGithub: boolean, isExample: boolean) => TransformFn;
+const generateEnv: GenerateEnv = (demoGithub, isExample) =>
 	transforms.text(({ content, text }) => {
 		content = text.upsert(content, 'ORIGIN', {
 			value: isExample ? `""` : `"http://localhost:5173"`,
diff --git a/packages/sv/src/addons/common.ts b/packages/sv/src/addons/common.ts
index f217fb4fa..664dcdefc 100644
--- a/packages/sv/src/addons/common.ts
+++ b/packages/sv/src/addons/common.ts
@@ -1,4 +1,4 @@
-import { type SvelteAst, transforms } from '@sveltejs/sv-utils';
+import { type SvelteAst, type TransformFn, transforms } from '@sveltejs/sv-utils';
 import process from 'node:process';
 
 export const addEslintConfigPrettier = transforms.script(({ ast, js }) => {
@@ -57,7 +57,7 @@ export const addEslintConfigPrettier = transforms.script(({ ast, js }) => {
 	}
 });
 
-type AddToDemoPage = (path: string, language: 'ts' | 'js') => (content: string) => string;
+type AddToDemoPage = (path: string, language: 'ts' | 'js') => TransformFn;
 export const addToDemoPage: AddToDemoPage = (path, language) =>
 	transforms.svelteScript({ language }, ({ ast, js, svelte }) => {
 		for (const node of ast.fragment.nodes) {
diff --git a/packages/sv/src/addons/drizzle.ts b/packages/sv/src/addons/drizzle.ts
index 0b2f6b51d..de9ab3fa7 100644
--- a/packages/sv/src/addons/drizzle.ts
+++ b/packages/sv/src/addons/drizzle.ts
@@ -1,4 +1,11 @@
-import { color, dedent, transforms, resolveCommand, fileExists } from '@sveltejs/sv-utils';
+import {
+	color,
+	dedent,
+	type TransformFn,
+	transforms,
+	resolveCommand,
+	fileExists
+} from '@sveltejs/sv-utils';
 import crypto from 'node:crypto';
 import fs from 'node:fs';
 import path from 'node:path';
@@ -122,8 +129,8 @@ export default defineAddon({
 		if (options.sqlite === 'libsql' || options.sqlite === 'turso')
 			sv.devDependency('@libsql/client', '^0.17.0');
 
-		sv.file('.env', generateEnvFileContent(options, false));
-		sv.file('.env.example', generateEnvFileContent(options, true));
+		sv.file('.env', generateEnv(options, false));
+		sv.file('.env.example', generateEnv(options, true));
 
 		if (options.docker && (options.mysql === 'mysql2' || options.postgresql === 'postgres.js')) {
 			const composeFileOptions = ['docker-compose.yml', 'docker-compose.yaml', 'compose.yaml'];
@@ -505,11 +512,8 @@ export default defineAddon({
 	}
 });
 
-type GenerateEnvFileContent = (
-	opts: OptionValues<typeof options>,
-	isExample: boolean
-) => (content: string) => string;
-const generateEnvFileContent: GenerateEnvFileContent = (opts, isExample) =>
+type GenerateEnv = (opts: OptionValues<typeof options>, isExample: boolean) => TransformFn;
+const generateEnv: GenerateEnv = (opts, isExample) =>
 	transforms.text(({ content, text }) => {
 		const DB_URL_KEY = 'DATABASE_URL';
 

From 5f82a720adfb657c5f9fdc993ad039a3d6913eff Mon Sep 17 00:00:00 2001
From: Scott Wu <sw@scottwu.ca>
Date: Mon, 30 Mar 2026 18:20:47 +0800
Subject: [PATCH 3/8] handle false

---
 packages/sv/src/addons/better-auth.ts |  8 ++++----
 packages/sv/src/addons/mcp.ts         |  2 +-
 packages/sv/src/core/config.ts        |  2 +-
 packages/sv/src/core/engine.ts        | 10 ++++------
 4 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/packages/sv/src/addons/better-auth.ts b/packages/sv/src/addons/better-auth.ts
index 6e8895fa9..838a407d3 100644
--- a/packages/sv/src/addons/better-auth.ts
+++ b/packages/sv/src/addons/better-auth.ts
@@ -294,7 +294,7 @@ export default defineAddon({
 					if (content) {
 						const filePath = `${directory.kitRoutes}/demo/better-auth/login/+page.server.${language}`;
 						log.warn(`Existing ${color.warning(filePath)} file. Could not update.`);
-						return content;
+						return false;
 					}
 
 					const [ts] = createPrinter(language === 'ts');
@@ -398,7 +398,7 @@ export default defineAddon({
 				if (content) {
 					const filePath = `${directory.kitRoutes}/demo/better-auth/login/+page.svelte`;
 					log.warn(`Existing ${color.warning(filePath)} file. Could not update.`);
-					return content;
+					return false;
 				}
 
 				const tailwind = dependencyVersion('@tailwindcss/vite') !== undefined;
@@ -462,7 +462,7 @@ export default defineAddon({
 				if (content) {
 					const filePath = `${directory.kitRoutes}/demo/better-auth/+page.server.${language}`;
 					log.warn(`Existing ${color.warning(filePath)} file. Could not update.`);
-					return content;
+					return false;
 				}
 
 				const [ts] = createPrinter(language === 'ts');
@@ -495,7 +495,7 @@ export default defineAddon({
 				if (content) {
 					const filePath = `${directory.kitRoutes}/demo/better-auth/+page.svelte`;
 					log.warn(`Existing ${color.warning(filePath)} file. Could not update.`);
-					return content;
+					return false;
 				}
 
 				const tailwind = dependencyVersion('@tailwindcss/vite') !== undefined;
diff --git a/packages/sv/src/addons/mcp.ts b/packages/sv/src/addons/mcp.ts
index e83a4659c..548f78e6f 100644
--- a/packages/sv/src/addons/mcp.ts
+++ b/packages/sv/src/addons/mcp.ts
@@ -143,7 +143,7 @@ export default defineAddon({
 				sv.file(agentPath, (content) => {
 					if (content) {
 						filesExistingAlready.push(agentPath);
-						return content;
+						return false;
 					}
 					filesAdded.push(agentPath);
 					return agentFile?.contents ?? '';
diff --git a/packages/sv/src/core/config.ts b/packages/sv/src/core/config.ts
index a89e4a9a6..feae4f2ee 100644
--- a/packages/sv/src/core/config.ts
+++ b/packages/sv/src/core/config.ts
@@ -30,7 +30,7 @@ export type SvApi = {
 	/** Execute a command in the workspace. */
 	execute: (args: string[], stdio: 'inherit' | 'pipe') => Promise<void>;
 	/** Edit a file in the workspace. (will create it if it doesn't exist) */
-	file: (path: string, edit: (content: string) => string) => void;
+	file: (path: string, edit: (content: string) => string | false) => void;
 };
 
 export type Addon<Args extends OptionDefinition, Id extends string = string> = {
diff --git a/packages/sv/src/core/engine.ts b/packages/sv/src/core/engine.ts
index f89ef28a6..f0f71c833 100644
--- a/packages/sv/src/core/engine.ts
+++ b/packages/sv/src/core/engine.ts
@@ -180,13 +180,11 @@ async function runAddon({ addon, loaded, multiple, workspace, workspaceOptions }
 	const sv: SvApi = {
 		file: (path, edit) => {
 			try {
-				const exists = fileExists(workspace.cwd, path);
-				let fileContent = exists ? readFile(workspace.cwd, path) : '';
-				fileContent = edit(fileContent);
-				// skip writing when the edit returns an empty string (e.g. no content to create)
-				if (!fileContent) return fileContent;
+				const content = fileExists(workspace.cwd, path) ? readFile(workspace.cwd, path) : '';
+				const editedContent = edit(content);
+				if (editedContent === '' || editedContent === false) return content;
 
-				writeFile(workspace.cwd, path, fileContent);
+				writeFile(workspace.cwd, path, content);
 				files.add(path);
 			} catch (e) {
 				if (e instanceof Error) {

From d3513c9e7d5930c0186729451227aa504e93957c Mon Sep 17 00:00:00 2001
From: Scott Wu <sw@scottwu.ca>
Date: Mon, 30 Mar 2026 18:54:47 +0800
Subject: [PATCH 4/8] `TransformFn` intellisense

---
 packages/sv-utils/src/tooling/transforms.ts | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/packages/sv-utils/src/tooling/transforms.ts b/packages/sv-utils/src/tooling/transforms.ts
index 1de419038..c673f4949 100644
--- a/packages/sv-utils/src/tooling/transforms.ts
+++ b/packages/sv-utils/src/tooling/transforms.ts
@@ -128,7 +128,7 @@ export const transforms = {
 			js: typeof jsNs;
 		}) => void | false,
 		options?: TransformOptions
-	): (content: string) => string {
+	): TransformFn {
 		return (content) => {
 			const parsed = withParseError(() => parseSvelte(content), options);
 			if (!parsed) return content;
@@ -156,7 +156,7 @@ export const transforms = {
 			css: typeof cssNs;
 		}) => void | false,
 		options?: TransformOptions
-	): (content: string) => string {
+	): TransformFn {
 		return (content) => {
 			const parsed = withParseError(() => parseCss(content), options);
 			if (!parsed) return content;
@@ -174,7 +174,7 @@ export const transforms = {
 	json<T = any>(
 		cb: (file: { data: T; content: string; json: typeof jsonNs }) => void | false,
 		options?: TransformOptions
-	): (content: string) => string {
+	): TransformFn {
 		return (content) => {
 			const parsed = withParseError(() => parseJson(content), options);
 			if (!parsed) return content;
@@ -192,7 +192,7 @@ export const transforms = {
 	yaml(
 		cb: (file: { data: ReturnType<typeof parseYaml>['data']; content: string }) => void | false,
 		options?: TransformOptions
-	): (content: string) => string {
+	): TransformFn {
 		return (content) => {
 			const parsed = withParseError(() => parseYaml(content), options);
 			if (!parsed) return content;
@@ -210,7 +210,7 @@ export const transforms = {
 	toml(
 		cb: (file: { data: TomlTable; content: string }) => void | false,
 		options?: TransformOptions
-	): (content: string) => string {
+	): TransformFn {
 		return (content) => {
 			const parsed = withParseError(() => parseToml(content), options);
 			if (!parsed) return content;
@@ -228,7 +228,7 @@ export const transforms = {
 	html(
 		cb: (file: { ast: SvelteAst.Fragment; content: string; html: typeof htmlNs }) => void | false,
 		options?: TransformOptions
-	): (content: string) => string {
+	): TransformFn {
 		return (content) => {
 			const parsed = withParseError(() => parseHtml(content), options);
 			if (!parsed) return content;
@@ -244,9 +244,7 @@ export const transforms = {
 	 * Unlike other transforms there's no AST here - just string in, string out.
 	 * Return the new content, or `false` to abort (original content is returned unchanged).
 	 */
-	text(
-		cb: (file: { content: string; text: typeof textNs }) => string | false
-	): (content: string) => string {
+	text(cb: (file: { content: string; text: typeof textNs }) => string | false): TransformFn {
 		return (content) => {
 			const result = cb({ content, text: textNs });
 			if (result === false) return content;

From 93c87af8f423fd1e1374eb78db026c63758ec195 Mon Sep 17 00:00:00 2001
From: Scott Wu <sw@scottwu.ca>
Date: Mon, 30 Mar 2026 18:54:55 +0800
Subject: [PATCH 5/8] return false docs

---
 packages/sv/src/core/config.ts | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/packages/sv/src/core/config.ts b/packages/sv/src/core/config.ts
index feae4f2ee..5963eedbb 100644
--- a/packages/sv/src/core/config.ts
+++ b/packages/sv/src/core/config.ts
@@ -29,7 +29,11 @@ export type SvApi = {
 	devDependency: (pkg: string, version: string) => void;
 	/** Execute a command in the workspace. */
 	execute: (args: string[], stdio: 'inherit' | 'pipe') => Promise<void>;
-	/** Edit a file in the workspace. (will create it if it doesn't exist) */
+	/**
+	 * Edit a file in the workspace. (will create it if it doesn't exist)
+	 *
+	 * Return `false` from the callback to abort - the original content is returned unchanged.
+	 */
 	file: (path: string, edit: (content: string) => string | false) => void;
 };
 

From 7eb6fe6705e34d11bfbe3ae843f8c36c6ffb94df Mon Sep 17 00:00:00 2001
From: Scott Wu <sw@scottwu.ca>
Date: Mon, 30 Mar 2026 19:07:31 +0800
Subject: [PATCH 6/8] missed a spot

---
 packages/sv/src/addons/drizzle.ts | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/packages/sv/src/addons/drizzle.ts b/packages/sv/src/addons/drizzle.ts
index de9ab3fa7..5ed97003e 100644
--- a/packages/sv/src/addons/drizzle.ts
+++ b/packages/sv/src/addons/drizzle.ts
@@ -133,18 +133,23 @@ export default defineAddon({
 		sv.file('.env.example', generateEnv(options, true));
 
 		if (options.docker && (options.mysql === 'mysql2' || options.postgresql === 'postgres.js')) {
-			const composeFileOptions = ['docker-compose.yml', 'docker-compose.yaml', 'compose.yaml'];
-			let composeFile = '';
-			for (const option of composeFileOptions) {
-				composeFile = option;
-				if (fs.existsSync(path.resolve(cwd, option))) break;
-			}
-			if (composeFile === '') throw new Error('unreachable state...');
+			const composeFileOptions = [
+				// First item has higher priority
+				'compose.yaml', // canonical name
+				'compose.yml',
+				'docker-compose.yaml', // for backward compatibility
+				'docker-compose.yml' // for backward compatibility
+			];
+
+			const composeFile = composeFileOptions.find((option) =>
+				fs.existsSync(path.resolve(cwd, option))
+			);
+
+			if (!composeFile) throw new Error('unreachable state...');
 
 			sv.file(composeFile, (content) => {
-				// if the file already exists, don't modify it
-				// (in the future, we could add some tooling for modifying yaml)
-				if (content.length > 0) return content;
+				// `transform.yaml` not implemented. Therefore, abort if file exist.
+				if (content.length > 0) return false;
 
 				const imageName = options.database === 'mysql' ? 'mysql' : 'postgres';
 				const port = PORTS[options.database];

From 6f8193cd0a0fb7edfaa82e8ef6ab0643ecbb2c80 Mon Sep 17 00:00:00 2001
From: Scott Wu <sw@scottwu.ca>
Date: Mon, 30 Mar 2026 19:52:33 +0800
Subject: [PATCH 7/8] fix return false

---
 packages/sv/src/core/engine.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/sv/src/core/engine.ts b/packages/sv/src/core/engine.ts
index f0f71c833..1c7656467 100644
--- a/packages/sv/src/core/engine.ts
+++ b/packages/sv/src/core/engine.ts
@@ -184,7 +184,7 @@ async function runAddon({ addon, loaded, multiple, workspace, workspaceOptions }
 				const editedContent = edit(content);
 				if (editedContent === '' || editedContent === false) return content;
 
-				writeFile(workspace.cwd, path, content);
+				writeFile(workspace.cwd, path, editedContent);
 				files.add(path);
 			} catch (e) {
 				if (e instanceof Error) {

From 21ac9308e620dc4d09235f6a81376cb6d28fd476 Mon Sep 17 00:00:00 2001
From: Scott Wu <sw@scottwu.ca>
Date: Mon, 30 Mar 2026 20:05:30 +0800
Subject: [PATCH 8/8] fix

---
 packages/sv/src/addons/drizzle.ts | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/packages/sv/src/addons/drizzle.ts b/packages/sv/src/addons/drizzle.ts
index 5ed97003e..621191057 100644
--- a/packages/sv/src/addons/drizzle.ts
+++ b/packages/sv/src/addons/drizzle.ts
@@ -141,14 +141,12 @@ export default defineAddon({
 				'docker-compose.yml' // for backward compatibility
 			];
 
-			const composeFile = composeFileOptions.find((option) =>
-				fs.existsSync(path.resolve(cwd, option))
-			);
-
-			if (!composeFile) throw new Error('unreachable state...');
+			const composeFile =
+				composeFileOptions.find((option) => fs.existsSync(path.resolve(cwd, option))) ??
+				'compose.yaml';
 
 			sv.file(composeFile, (content) => {
-				// `transform.yaml` not implemented. Therefore, abort if file exist.
+				// `transforms.yaml` not implemented. Therefore, abort if file exist.
 				if (content.length > 0) return false;
 
 				const imageName = options.database === 'mysql' ? 'mysql' : 'postgres';