From e3bae6d3a963fd77575ed6566d398ea0222ea7d1 Mon Sep 17 00:00:00 2001
From: Theo Steiner <theosteiner@gmail.com>
Date: Sat, 2 Apr 2022 19:31:03 +0900
Subject: [PATCH 01/10] Set checkJs to false in no-typescript scaffold

---
 packages/create-svelte/shared/-typescript/jsconfig.json | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/packages/create-svelte/shared/-typescript/jsconfig.json b/packages/create-svelte/shared/-typescript/jsconfig.json
index 81ff9770cd8a..e8acf53c104e 100644
--- a/packages/create-svelte/shared/-typescript/jsconfig.json
+++ b/packages/create-svelte/shared/-typescript/jsconfig.json
@@ -1,3 +1,6 @@
 {
-	"extends": "./.svelte-kit/tsconfig.json"
+	"extends": "./.svelte-kit/tsconfig.json",
+	"compilerOptions": {
+		"checkJs": false
+	}
 }

From 9160b9da0213bd76a56ea47fb6a3216c9ccd5f88 Mon Sep 17 00:00:00 2001
From: Theo Steiner <theosteiner@gmail.com>
Date: Tue, 5 Apr 2022 13:11:20 +0900
Subject: [PATCH 02/10] [enhance] add selection for type checking to
 create-svelte

---
 packages/create-svelte/bin.js              | 18 ++++++++++++------
 packages/create-svelte/types/internal.d.ts |  3 ++-
 2 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/packages/create-svelte/bin.js b/packages/create-svelte/bin.js
index 8439db01fc31..3af9c8896c3b 100755
--- a/packages/create-svelte/bin.js
+++ b/packages/create-svelte/bin.js
@@ -70,12 +70,15 @@ async function main() {
 					})
 				},
 				{
-					type: 'toggle',
-					name: 'typescript',
-					message: 'Use TypeScript?',
+					type: 'select',
+					name: 'types',
+					message: 'Add type checking to your project?',
 					initial: false,
-					active: 'Yes',
-					inactive: 'No'
+					choices: [
+						{ title: 'No', value: false },
+						{ title: 'TypeScript', value: 'typescript' },
+						{ title: 'Type checked JavaScript', value: 'checkjs' }
+					]
 				},
 				{
 					type: 'toggle',
@@ -116,9 +119,12 @@ async function main() {
 
 	console.log(bold(green('\nYour project is ready!')));
 
-	if (options.typescript) {
+	if (options.types === 'typescript') {
 		console.log(bold('✔ Typescript'));
 		console.log('  Inside Svelte components, use <script lang="ts">');
+	} else if (options.types === 'checkjs') {
+		console.log(bold('✔ Type checked JavaScript'));
+		console.log('  https://www.typescriptlang.org/tsconfig#checkJs');
 	}
 
 	if (options.eslint) {
diff --git a/packages/create-svelte/types/internal.d.ts b/packages/create-svelte/types/internal.d.ts
index 115e9296ea6c..9f431c3573e1 100644
--- a/packages/create-svelte/types/internal.d.ts
+++ b/packages/create-svelte/types/internal.d.ts
@@ -1,7 +1,7 @@
 export type Options = {
 	name: string;
 	template: 'default' | 'skeleton';
-	typescript: boolean;
+	types: false | 'typescript' | 'checkjs';
 	prettier: boolean;
 	eslint: boolean;
 	playwright: boolean;
@@ -16,6 +16,7 @@ export type Condition =
 	| 'eslint'
 	| 'prettier'
 	| 'typescript'
+	| 'checkjs'
 	| 'playwright'
 	| 'skeleton'
 	| 'default';

From 7dd02192da933a76271b596d7bdec501f31511f4 Mon Sep 17 00:00:00 2001
From: Theo Steiner <theosteiner@gmail.com>
Date: Tue, 5 Apr 2022 13:11:57 +0900
Subject: [PATCH 03/10] Add changelog

---
 .changeset/cold-boats-wave.md | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 .changeset/cold-boats-wave.md

diff --git a/.changeset/cold-boats-wave.md b/.changeset/cold-boats-wave.md
new file mode 100644
index 000000000000..dd2e65846602
--- /dev/null
+++ b/.changeset/cold-boats-wave.md
@@ -0,0 +1,5 @@
+---
+'create-svelte': patch
+---
+
+Disable type checking by default for non-typescript projects.

From cee9253daaeb7c9a1f4022d12c9f9960ac46dd0c Mon Sep 17 00:00:00 2001
From: Theo Steiner <theosteiner@gmail.com>
Date: Tue, 5 Apr 2022 13:55:27 +0900
Subject: [PATCH 04/10] Adjust file inclusion logic to checkjs option

---
 packages/create-svelte/index.js                | 18 +++++++++++-------
 .../shared/+checkjs/jsconfig.json              |  6 ++++++
 .../jsconfig.json                              |  0
 3 files changed, 17 insertions(+), 7 deletions(-)
 create mode 100644 packages/create-svelte/shared/+checkjs/jsconfig.json
 rename packages/create-svelte/shared/{-typescript => -typescript-checkjs}/jsconfig.json (100%)

diff --git a/packages/create-svelte/index.js b/packages/create-svelte/index.js
index 0848fdcde7f2..ee6d6ec458bc 100755
--- a/packages/create-svelte/index.js
+++ b/packages/create-svelte/index.js
@@ -11,7 +11,7 @@ import { mkdirp, copy, dist } from './utils.js';
 export async function create(cwd, options) {
 	mkdirp(cwd);
 
-	write_template_files(options.template, options.typescript, options.name, cwd);
+	write_template_files(options.template, options.types, options.name, cwd);
 	write_common_files(cwd, options, options.name);
 }
 
@@ -21,12 +21,12 @@ export async function create(cwd, options) {
  * @param {string} name
  * @param {string} cwd
  */
-function write_template_files(template, typescript, name, cwd) {
+function write_template_files(template, types, name, cwd) {
 	const dir = dist(`templates/${template}`);
 	copy(`${dir}/assets`, cwd, (name) => name.replace('DOT-', '.'));
 	copy(`${dir}/package.json`, `${cwd}/package.json`);
 
-	const manifest = `${dir}/files.${typescript ? 'ts' : 'js'}.json`;
+	const manifest = `${dir}/files.${types === 'typescript' ? 'ts' : 'js'}.json`;
 	const files = /** @type {import('./types/internal').File[]} */ (
 		JSON.parse(fs.readFileSync(manifest, 'utf-8'))
 	);
@@ -40,7 +40,7 @@ function write_template_files(template, typescript, name, cwd) {
 }
 
 /**
- *
+ build*
  * @param {string} cwd
  * @param {import('./types/internal').Options} options
  * @param {string} name
@@ -83,9 +83,13 @@ function write_common_files(cwd, options, name) {
  * @returns {boolean}
  */
 function matches_condition(condition, options) {
-	return condition === 'default' || condition === 'skeleton'
-		? options.template === condition
-		: options[condition];
+	if (condition === 'default' || condition === 'skeleton') {
+		return options.template === condition;
+	}
+	if (condition === 'typescript' || condition === 'checkjs') {
+		return options.types === condition;
+	}
+	return options[condition];
 }
 
 /**
diff --git a/packages/create-svelte/shared/+checkjs/jsconfig.json b/packages/create-svelte/shared/+checkjs/jsconfig.json
new file mode 100644
index 000000000000..df77605d0d91
--- /dev/null
+++ b/packages/create-svelte/shared/+checkjs/jsconfig.json
@@ -0,0 +1,6 @@
+{
+	"extends": "./.svelte-kit/tsconfig.json",
+	"compilerOptions": {
+		"checkJs": true
+	}
+}
diff --git a/packages/create-svelte/shared/-typescript/jsconfig.json b/packages/create-svelte/shared/-typescript-checkjs/jsconfig.json
similarity index 100%
rename from packages/create-svelte/shared/-typescript/jsconfig.json
rename to packages/create-svelte/shared/-typescript-checkjs/jsconfig.json

From 76f4d669493bf1162db514026a2b5c9e00129378 Mon Sep 17 00:00:00 2001
From: Rich Harris <hello@rich-harris.dev>
Date: Thu, 14 Apr 2022 15:20:11 -0400
Subject: [PATCH 05/10] add jsdoc annotations

---
 .../templates/default/src/hooks.ts            |  1 +
 .../templates/default/src/lib/Counter.svelte  |  4 +++
 .../templates/default/src/lib/form.ts         | 28 ++++++++++++++++++-
 .../default/src/routes/todos/_api.ts          |  5 ++++
 .../default/src/routes/todos/index.svelte     | 11 ++++++++
 .../default/src/routes/todos/index.ts         |  6 +++-
 6 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/packages/create-svelte/templates/default/src/hooks.ts b/packages/create-svelte/templates/default/src/hooks.ts
index d767555dd9ea..484afff5d85b 100644
--- a/packages/create-svelte/templates/default/src/hooks.ts
+++ b/packages/create-svelte/templates/default/src/hooks.ts
@@ -2,6 +2,7 @@ import cookie from 'cookie';
 import { v4 as uuid } from '@lukeed/uuid';
 import type { Handle } from '@sveltejs/kit';
 
+/** @type {import('@sveltejs/kit').Handle} */
 export const handle: Handle = async ({ event, resolve }) => {
 	const cookies = cookie.parse(event.request.headers.get('cookie') || '');
 	event.locals.userid = cookies.userid || uuid();
diff --git a/packages/create-svelte/templates/default/src/lib/Counter.svelte b/packages/create-svelte/templates/default/src/lib/Counter.svelte
index bb7127140914..50930bb2b742 100644
--- a/packages/create-svelte/templates/default/src/lib/Counter.svelte
+++ b/packages/create-svelte/templates/default/src/lib/Counter.svelte
@@ -7,6 +7,10 @@
 	$: displayed_count.set(count);
 	$: offset = modulo($displayed_count, 1);
 
+	/**
+	 * @param {number} n
+	 * @param {number} m
+	 */
 	function modulo(n: number, m: number) {
 		// handle negative numbers
 		return ((n % m) + m) % m;
diff --git a/packages/create-svelte/templates/default/src/lib/form.ts b/packages/create-svelte/templates/default/src/lib/form.ts
index 787a397d506f..4352c9a0f60a 100644
--- a/packages/create-svelte/templates/default/src/lib/form.ts
+++ b/packages/create-svelte/templates/default/src/lib/form.ts
@@ -2,6 +2,32 @@ import { invalidate } from '$app/navigation';
 
 // this action (https://svelte.dev/tutorial/actions) allows us to
 // progressively enhance a <form> that already works without JS
+/**
+ * @param {HTMLFormElement} form
+ * @param {{
+ *   pending?: ({ data, form }: { data: FormData; form: HTMLFormElement }) => void;
+ *   error?: ({
+ *     data,
+ *     form,
+ *     response,
+ *     error
+ *   }: {
+ *     data: FormData;
+ *     form: HTMLFormElement;
+ *     response: Response | null;
+ *     error: Error | null;
+ *   }) => void;
+ *   result?: ({
+ *     data,
+ *     form,
+ *     response
+ *   }: {
+ *     data: FormData;
+ *     response: Response;
+ *     form: HTMLFormElement;
+ *   }) => void;
+ * }} [opts]
+ */
 export function enhance(
 	form: HTMLFormElement,
 	{
@@ -31,7 +57,7 @@ export function enhance(
 			form: HTMLFormElement;
 		}) => void;
 	} = {}
-): { destroy: () => void } {
+) {
 	let current_token: unknown;
 
 	async function handle_submit(e: Event) {
diff --git a/packages/create-svelte/templates/default/src/routes/todos/_api.ts b/packages/create-svelte/templates/default/src/routes/todos/_api.ts
index 397cdda79151..d627ea021b4b 100644
--- a/packages/create-svelte/templates/default/src/routes/todos/_api.ts
+++ b/packages/create-svelte/templates/default/src/routes/todos/_api.ts
@@ -11,6 +11,11 @@
 
 const base = 'https://api.svelte.dev';
 
+/**
+ * @param {string} method
+ * @param {string} resource
+ * @param {Record<string, unknown>} [data]
+ */
 export function api(method: string, resource: string, data?: Record<string, unknown>) {
 	return fetch(`${base}/${resource}`, {
 		method,
diff --git a/packages/create-svelte/templates/default/src/routes/todos/index.svelte b/packages/create-svelte/templates/default/src/routes/todos/index.svelte
index 7f997c23d033..cd84d0b89695 100644
--- a/packages/create-svelte/templates/default/src/routes/todos/index.svelte
+++ b/packages/create-svelte/templates/default/src/routes/todos/index.svelte
@@ -3,6 +3,16 @@
 	import { scale } from 'svelte/transition';
 	import { flip } from 'svelte/animate';
 
+	/**
+	 * @typedef {{
+	 *   uid: string;
+	 *   created_at: Date;
+	 *   text: string;
+	 *   done: boolean;
+	 *   pending_delete: boolean;
+	 * }} Todo
+	 */
+
 	type Todo = {
 		uid: string;
 		created_at: Date;
@@ -11,6 +21,7 @@
 		pending_delete: boolean;
 	};
 
+	/** @type {Todo[]} */
 	export let todos: Todo[];
 </script>
 
diff --git a/packages/create-svelte/templates/default/src/routes/todos/index.ts b/packages/create-svelte/templates/default/src/routes/todos/index.ts
index fc8bd4b8efaf..5ca318899587 100644
--- a/packages/create-svelte/templates/default/src/routes/todos/index.ts
+++ b/packages/create-svelte/templates/default/src/routes/todos/index.ts
@@ -1,6 +1,7 @@
 import { api } from './_api';
-import type { RequestHandler } from '@sveltejs/kit';
+import type { RequestHandler } from './index';
 
+/** @type {import('./index').RequestHandler} */
 export const get: RequestHandler = async ({ locals }) => {
 	// locals.userid comes from src/hooks.js
 	const response = await api('get', `todos/${locals.userid}`);
@@ -28,6 +29,7 @@ export const get: RequestHandler = async ({ locals }) => {
 	};
 };
 
+/** @type {import('./index').RequestHandler} */
 export const post: RequestHandler = async ({ request, locals }) => {
 	const form = await request.formData();
 
@@ -47,6 +49,7 @@ const redirect = {
 	}
 };
 
+/** @type {import('./index').RequestHandler} */
 export const patch: RequestHandler = async ({ request, locals }) => {
 	const form = await request.formData();
 
@@ -58,6 +61,7 @@ export const patch: RequestHandler = async ({ request, locals }) => {
 	return redirect;
 };
 
+/** @type {import('./index').RequestHandler} */
 export const del: RequestHandler = async ({ request, locals }) => {
 	const form = await request.formData();
 

From dbe65f0f1f1f450ce820e2050558d07fef756ab5 Mon Sep 17 00:00:00 2001
From: Rich Harris <hello@rich-harris.dev>
Date: Thu, 14 Apr 2022 15:52:40 -0400
Subject: [PATCH 06/10] strip jsdoc from source

---
 .../create-svelte/scripts/build-templates.js  | 154 +++++++++---------
 1 file changed, 80 insertions(+), 74 deletions(-)

diff --git a/packages/create-svelte/scripts/build-templates.js b/packages/create-svelte/scripts/build-templates.js
index 3367ede9a46d..1acf1e354063 100644
--- a/packages/create-svelte/scripts/build-templates.js
+++ b/packages/create-svelte/scripts/build-templates.js
@@ -6,9 +6,9 @@ import { transform } from 'sucrase';
 import glob from 'tiny-glob/sync.js';
 import { mkdirp, rimraf } from '../utils.js';
 
-/** @param {string} typescript */
-function convert_typescript(typescript) {
-	const transformed = transform(typescript, {
+/** @param {string} content */
+function convert_typescript(content) {
+	const transformed = transform(content, {
 		transforms: ['typescript']
 	});
 
@@ -21,6 +21,11 @@ function convert_typescript(typescript) {
 	});
 }
 
+/** @param {string} content */
+function strip_jsdoc(content) {
+	return content.replace(/\/\*\*[\s\S]+?\*\/[\s\n]+/g, '');
+}
+
 /** @param {Set<string>} shared */
 async function generate_templates(shared) {
 	const templates = fs.readdirSync('templates');
@@ -43,6 +48,9 @@ async function generate_templates(shared) {
 		const meta_file = path.join(cwd, '.meta.json');
 		if (!fs.existsSync(meta_file)) throw new Error('Template must have a .meta.json file');
 
+		/** @type {import('../types/internal.js').File[]} */
+		const js = [];
+
 		/** @type {import('../types/internal.js').File[]} */
 		const ts = [];
 
@@ -64,12 +72,76 @@ async function generate_templates(shared) {
 			// ignore contents of .gitignore or .ignore
 			if (!gitignore.accepts(name) || !ignore.accepts(name) || name === '.ignore') return;
 
-			if (/\.(js|ts|svelte|svelte\.md)$/.test(name)) {
+			if (/\.(ts|svelte)$/.test(name)) {
 				const contents = fs.readFileSync(path.join(cwd, name), 'utf8');
-				ts.push({
-					name,
-					contents
-				});
+
+				if (name.endsWith('.d.ts')) {
+					if (name.endsWith('app.d.ts')) js.push({ name, contents });
+					ts.push({ name, contents });
+				} else if (name.endsWith('.ts')) {
+					ts.push({
+						name,
+						contents: strip_jsdoc(contents)
+					});
+
+					js.push({
+						name: name.replace(/\.ts$/, '.js'),
+						contents: convert_typescript(contents)
+					});
+				} else {
+					// we jump through some hoops, rather than just using svelte.preprocess,
+					// so that the output preserves the original formatting to the extent
+					// possible (e.g. preserving double line breaks). Sucrase is the best
+					// tool for the job because it just removes the types; Prettier then
+					// tidies up the end result
+					const js_contents = contents.replace(
+						/<script([^>]+)>([\s\S]+?)<\/script>/g,
+						(m, attrs, typescript) => {
+							// Sucrase assumes 'unused' imports (which _are_ used, but only
+							// in the markup) are type imports, and strips them. This step
+							// prevents it from drawing that conclusion
+							const imports = [];
+							const import_pattern = /import (.+?) from/g;
+							let import_match;
+							while ((import_match = import_pattern.exec(typescript))) {
+								const word_pattern = /[a-z_$][a-z0-9_$]*/gi;
+								let word_match;
+								while ((word_match = word_pattern.exec(import_match[1]))) {
+									imports.push(word_match[0]);
+								}
+							}
+
+							const suffix = `\n${imports.join(',')}`;
+
+							const transformed = transform(typescript + suffix, {
+								transforms: ['typescript']
+							}).code.slice(0, -suffix.length);
+
+							const contents = prettier
+								.format(transformed, {
+									parser: 'babel',
+									useTabs: true,
+									singleQuote: true,
+									trailingComma: 'none',
+									printWidth: 100
+								})
+								.trim()
+								.replace(/^(.)/gm, '\t$1');
+
+							return `<script${attrs.replace(' lang="ts"', '')}>\n${contents}\n</script>`;
+						}
+					);
+
+					js.push({
+						name,
+						contents: js_contents
+					});
+
+					ts.push({
+						name,
+						contents: strip_jsdoc(contents)
+					});
+				}
 			} else {
 				const dest = path.join(assets, name.replace(/^\./, 'DOT-'));
 				mkdirp(path.dirname(dest));
@@ -77,72 +149,6 @@ async function generate_templates(shared) {
 			}
 		});
 
-		/** @type {import('../types/internal.js').File[]} */
-		const js = [];
-
-		for (const file of ts) {
-			// The app.d.ts file makes TS/JS aware of some ambient modules, which are
-			// also needed for JS projects if people turn on "checkJs" in their jsonfig
-			if (file.name.endsWith('.d.ts')) {
-				if (file.name.endsWith('app.d.ts')) js.push(file);
-			} else if (file.name.endsWith('.ts')) {
-				js.push({
-					name: file.name.replace(/\.ts$/, '.js'),
-					contents: convert_typescript(file.contents)
-				});
-			} else if (file.name.endsWith('.svelte')) {
-				// we jump through some hoops, rather than just using svelte.preprocess,
-				// so that the output preserves the original formatting to the extent
-				// possible (e.g. preserving double line breaks). Sucrase is the best
-				// tool for the job because it just removes the types; Prettier then
-				// tidies up the end result
-				const contents = file.contents.replace(
-					/<script([^>]+)>([\s\S]+?)<\/script>/g,
-					(m, attrs, typescript) => {
-						// Sucrase assumes 'unused' imports (which _are_ used, but only
-						// in the markup) are type imports, and strips them. This step
-						// prevents it from drawing that conclusion
-						const imports = [];
-						const import_pattern = /import (.+?) from/g;
-						let import_match;
-						while ((import_match = import_pattern.exec(typescript))) {
-							const word_pattern = /[a-z_$][a-z0-9_$]*/gi;
-							let word_match;
-							while ((word_match = word_pattern.exec(import_match[1]))) {
-								imports.push(word_match[0]);
-							}
-						}
-
-						const suffix = `\n${imports.join(',')}`;
-
-						const transformed = transform(typescript + suffix, {
-							transforms: ['typescript']
-						}).code.slice(0, -suffix.length);
-
-						const contents = prettier
-							.format(transformed, {
-								parser: 'babel',
-								useTabs: true,
-								singleQuote: true,
-								trailingComma: 'none',
-								printWidth: 100
-							})
-							.trim()
-							.replace(/^(.)/gm, '\t$1');
-
-						return `<script${attrs.replace(' lang="ts"', '')}>\n${contents}\n</script>`;
-					}
-				);
-
-				js.push({
-					name: file.name,
-					contents
-				});
-			} else {
-				js.push(file);
-			}
-		}
-
 		fs.copyFileSync(meta_file, `${dir}/meta.json`);
 		fs.writeFileSync(`${dir}/files.ts.json`, JSON.stringify(ts, null, '\t'));
 		fs.writeFileSync(`${dir}/files.js.json`, JSON.stringify(js, null, '\t'));

From a9895d83119480909bf7179868b09b77babdb97b Mon Sep 17 00:00:00 2001
From: Rich Harris <hello@rich-harris.dev>
Date: Thu, 14 Apr 2022 17:39:39 -0400
Subject: [PATCH 07/10] tidy up

---
 packages/create-svelte/bin.js                 |  8 ++++----
 packages/create-svelte/index.js               |  2 +-
 .../scripts/update-template-repo-contents.js  |  2 +-
 .../shared/+checkjs/package.json              | 10 ++++++++++
 .../shared/+default+checkjs/package.json      |  5 +++++
 .../shared/+default+checkjs/svelte.config.js  | 20 +++++++++++++++++++
 .../shared/-typescript-checkjs/jsconfig.json  |  6 ------
 .../templates/default/src/lib/form.ts         |  3 ++-
 packages/create-svelte/types/internal.d.ts    |  2 +-
 9 files changed, 44 insertions(+), 14 deletions(-)
 create mode 100644 packages/create-svelte/shared/+checkjs/package.json
 create mode 100644 packages/create-svelte/shared/+default+checkjs/package.json
 create mode 100644 packages/create-svelte/shared/+default+checkjs/svelte.config.js
 delete mode 100644 packages/create-svelte/shared/-typescript-checkjs/jsconfig.json

diff --git a/packages/create-svelte/bin.js b/packages/create-svelte/bin.js
index 3af9c8896c3b..0997c21c274b 100755
--- a/packages/create-svelte/bin.js
+++ b/packages/create-svelte/bin.js
@@ -72,12 +72,12 @@ async function main() {
 				{
 					type: 'select',
 					name: 'types',
-					message: 'Add type checking to your project?',
+					message: 'Add type checking?',
 					initial: false,
 					choices: [
-						{ title: 'No', value: false },
+						{ title: 'Type-checked JavaScript', value: 'checkjs' },
 						{ title: 'TypeScript', value: 'typescript' },
-						{ title: 'Type checked JavaScript', value: 'checkjs' }
+						{ title: 'None', value: null }
 					]
 				},
 				{
@@ -123,7 +123,7 @@ async function main() {
 		console.log(bold('✔ Typescript'));
 		console.log('  Inside Svelte components, use <script lang="ts">');
 	} else if (options.types === 'checkjs') {
-		console.log(bold('✔ Type checked JavaScript'));
+		console.log(bold('✔ Type-checked JavaScript'));
 		console.log('  https://www.typescriptlang.org/tsconfig#checkJs');
 	}
 
diff --git a/packages/create-svelte/index.js b/packages/create-svelte/index.js
index ee6d6ec458bc..68e3615db104 100755
--- a/packages/create-svelte/index.js
+++ b/packages/create-svelte/index.js
@@ -17,7 +17,7 @@ export async function create(cwd, options) {
 
 /**
  * @param {string} template
- * @param {boolean} typescript
+ * @param {'typescript' | 'checkjs' | null} types
  * @param {string} name
  * @param {string} cwd
  */
diff --git a/packages/create-svelte/scripts/update-template-repo-contents.js b/packages/create-svelte/scripts/update-template-repo-contents.js
index 54c93b629a8e..84a2fa7be57c 100644
--- a/packages/create-svelte/scripts/update-template-repo-contents.js
+++ b/packages/create-svelte/scripts/update-template-repo-contents.js
@@ -17,7 +17,7 @@ await create(repo, {
 	name: 'kit-template-default',
 	template: 'default',
 	eslint: false,
-	typescript: false,
+	types: 'js',
 	prettier: true,
 	playwright: false
 });
diff --git a/packages/create-svelte/shared/+checkjs/package.json b/packages/create-svelte/shared/+checkjs/package.json
new file mode 100644
index 000000000000..6d4d5148bf98
--- /dev/null
+++ b/packages/create-svelte/shared/+checkjs/package.json
@@ -0,0 +1,10 @@
+{
+	"scripts": {
+		"check": "svelte-check --tsconfig ./jsconfig.json",
+		"check:watch": "svelte-check --tsconfig ./jsconfig.json --watch"
+	},
+	"devDependencies": {
+		"typescript": "~4.6.2",
+		"svelte-check": "^2.2.6"
+	}
+}
diff --git a/packages/create-svelte/shared/+default+checkjs/package.json b/packages/create-svelte/shared/+default+checkjs/package.json
new file mode 100644
index 000000000000..344e137f7c5a
--- /dev/null
+++ b/packages/create-svelte/shared/+default+checkjs/package.json
@@ -0,0 +1,5 @@
+{
+	"devDependencies": {
+		"@types/cookie": "^0.4.1"
+	}
+}
diff --git a/packages/create-svelte/shared/+default+checkjs/svelte.config.js b/packages/create-svelte/shared/+default+checkjs/svelte.config.js
new file mode 100644
index 000000000000..1fa366b0c670
--- /dev/null
+++ b/packages/create-svelte/shared/+default+checkjs/svelte.config.js
@@ -0,0 +1,20 @@
+import adapter from '@sveltejs/adapter-auto';
+import preprocess from 'svelte-preprocess';
+
+/** @type {import('@sveltejs/kit').Config} */
+const config = {
+	// Consult https://github.com/sveltejs/svelte-preprocess
+	// for more information about preprocessors
+	preprocess: preprocess(),
+
+	kit: {
+		adapter: adapter(),
+
+		// Override http methods in the Todo forms
+		methodOverride: {
+			allowed: ['PATCH', 'DELETE']
+		}
+	}
+};
+
+export default config;
diff --git a/packages/create-svelte/shared/-typescript-checkjs/jsconfig.json b/packages/create-svelte/shared/-typescript-checkjs/jsconfig.json
deleted file mode 100644
index e8acf53c104e..000000000000
--- a/packages/create-svelte/shared/-typescript-checkjs/jsconfig.json
+++ /dev/null
@@ -1,6 +0,0 @@
-{
-	"extends": "./.svelte-kit/tsconfig.json",
-	"compilerOptions": {
-		"checkJs": false
-	}
-}
diff --git a/packages/create-svelte/templates/default/src/lib/form.ts b/packages/create-svelte/templates/default/src/lib/form.ts
index 4352c9a0f60a..9a66bf9e397b 100644
--- a/packages/create-svelte/templates/default/src/lib/form.ts
+++ b/packages/create-svelte/templates/default/src/lib/form.ts
@@ -60,7 +60,8 @@ export function enhance(
 ) {
 	let current_token: unknown;
 
-	async function handle_submit(e: Event) {
+	/** @param {SubmitEvent} e */
+	async function handle_submit(e: SubmitEvent) {
 		const token = (current_token = {});
 
 		e.preventDefault();
diff --git a/packages/create-svelte/types/internal.d.ts b/packages/create-svelte/types/internal.d.ts
index 9f431c3573e1..e0a6ede97b72 100644
--- a/packages/create-svelte/types/internal.d.ts
+++ b/packages/create-svelte/types/internal.d.ts
@@ -1,7 +1,7 @@
 export type Options = {
 	name: string;
 	template: 'default' | 'skeleton';
-	types: false | 'typescript' | 'checkjs';
+	types: 'typescript' | 'checkjs' | null;
 	prettier: boolean;
 	eslint: boolean;
 	playwright: boolean;

From a010cb7892977149e41ff491c09546a18987453e Mon Sep 17 00:00:00 2001
From: Rich Harris <hello@rich-harris.dev>
Date: Thu, 14 Apr 2022 17:47:51 -0400
Subject: [PATCH 08/10] oops

---
 packages/create-svelte/scripts/update-template-repo-contents.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/create-svelte/scripts/update-template-repo-contents.js b/packages/create-svelte/scripts/update-template-repo-contents.js
index 84a2fa7be57c..6cd67e1c0b86 100644
--- a/packages/create-svelte/scripts/update-template-repo-contents.js
+++ b/packages/create-svelte/scripts/update-template-repo-contents.js
@@ -17,7 +17,7 @@ await create(repo, {
 	name: 'kit-template-default',
 	template: 'default',
 	eslint: false,
-	types: 'js',
+	types: 'checkjs',
 	prettier: true,
 	playwright: false
 });

From fce37b67b1bb2e782f1fbde42be3a070b4aade68 Mon Sep 17 00:00:00 2001
From: Rich Harris <richard.a.harris@gmail.com>
Date: Thu, 14 Apr 2022 18:17:47 -0400
Subject: [PATCH 09/10] Update packages/create-svelte/index.js

Co-authored-by: Ben McCann <322311+benmccann@users.noreply.github.com>
---
 packages/create-svelte/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/create-svelte/index.js b/packages/create-svelte/index.js
index 68e3615db104..0b1b090cbf78 100755
--- a/packages/create-svelte/index.js
+++ b/packages/create-svelte/index.js
@@ -40,7 +40,7 @@ function write_template_files(template, types, name, cwd) {
 }
 
 /**
- build*
+ *
  * @param {string} cwd
  * @param {import('./types/internal').Options} options
  * @param {string} name

From 5c32844d4599970a1b3100bc0f713d2b0284d717 Mon Sep 17 00:00:00 2001
From: Rich Harris <hello@rich-harris.dev>
Date: Thu, 14 Apr 2022 22:13:40 -0400
Subject: [PATCH 10/10] strip jsdoc annotations when no typechecking is
 selected

---
 packages/create-svelte/index.js               |  2 +-
 .../create-svelte/scripts/build-templates.js  | 47 +++++++++++++------
 2 files changed, 33 insertions(+), 16 deletions(-)

diff --git a/packages/create-svelte/index.js b/packages/create-svelte/index.js
index 0b1b090cbf78..716c036618c3 100755
--- a/packages/create-svelte/index.js
+++ b/packages/create-svelte/index.js
@@ -26,7 +26,7 @@ function write_template_files(template, types, name, cwd) {
 	copy(`${dir}/assets`, cwd, (name) => name.replace('DOT-', '.'));
 	copy(`${dir}/package.json`, `${cwd}/package.json`);
 
-	const manifest = `${dir}/files.${types === 'typescript' ? 'ts' : 'js'}.json`;
+	const manifest = `${dir}/files.types=${types}.json`;
 	const files = /** @type {import('./types/internal').File[]} */ (
 		JSON.parse(fs.readFileSync(manifest, 'utf-8'))
 	);
diff --git a/packages/create-svelte/scripts/build-templates.js b/packages/create-svelte/scripts/build-templates.js
index 1acf1e354063..c9d21f9a0e19 100644
--- a/packages/create-svelte/scripts/build-templates.js
+++ b/packages/create-svelte/scripts/build-templates.js
@@ -48,11 +48,12 @@ async function generate_templates(shared) {
 		const meta_file = path.join(cwd, '.meta.json');
 		if (!fs.existsSync(meta_file)) throw new Error('Template must have a .meta.json file');
 
-		/** @type {import('../types/internal.js').File[]} */
-		const js = [];
-
-		/** @type {import('../types/internal.js').File[]} */
-		const ts = [];
+		/** @type {Record<string, import('../types/internal.js').File[]>} */
+		const types = {
+			typescript: [],
+			checkjs: [],
+			null: []
+		};
 
 		glob('**/*', { cwd, filesOnly: true, dot: true }).forEach((name) => {
 			// the package.template.json thing is a bit annoying — basically we want
@@ -76,17 +77,24 @@ async function generate_templates(shared) {
 				const contents = fs.readFileSync(path.join(cwd, name), 'utf8');
 
 				if (name.endsWith('.d.ts')) {
-					if (name.endsWith('app.d.ts')) js.push({ name, contents });
-					ts.push({ name, contents });
+					if (name.endsWith('app.d.ts')) types.checkjs.push({ name, contents });
+					types.typescript.push({ name, contents });
 				} else if (name.endsWith('.ts')) {
-					ts.push({
+					const js = convert_typescript(contents);
+
+					types.typescript.push({
 						name,
 						contents: strip_jsdoc(contents)
 					});
 
-					js.push({
+					types.checkjs.push({
+						name: name.replace(/\.ts$/, '.js'),
+						contents: js
+					});
+
+					types.null.push({
 						name: name.replace(/\.ts$/, '.js'),
-						contents: convert_typescript(contents)
+						contents: strip_jsdoc(js)
 					});
 				} else {
 					// we jump through some hoops, rather than just using svelte.preprocess,
@@ -132,14 +140,19 @@ async function generate_templates(shared) {
 						}
 					);
 
-					js.push({
+					types.typescript.push({
+						name,
+						contents: strip_jsdoc(contents)
+					});
+
+					types.checkjs.push({
 						name,
 						contents: js_contents
 					});
 
-					ts.push({
+					types.null.push({
 						name,
-						contents: strip_jsdoc(contents)
+						contents: strip_jsdoc(js_contents)
 					});
 				}
 			} else {
@@ -150,8 +163,12 @@ async function generate_templates(shared) {
 		});
 
 		fs.copyFileSync(meta_file, `${dir}/meta.json`);
-		fs.writeFileSync(`${dir}/files.ts.json`, JSON.stringify(ts, null, '\t'));
-		fs.writeFileSync(`${dir}/files.js.json`, JSON.stringify(js, null, '\t'));
+		fs.writeFileSync(
+			`${dir}/files.types=typescript.json`,
+			JSON.stringify(types.typescript, null, '\t')
+		);
+		fs.writeFileSync(`${dir}/files.types=checkjs.json`, JSON.stringify(types.checkjs, null, '\t'));
+		fs.writeFileSync(`${dir}/files.types=null.json`, JSON.stringify(types.null, null, '\t'));
 	}
 }