Version info thingy

.changeset/yellow-squids-explain.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+chore: add version info to window

packages/playground/src/App.svelte

@@ -1,3 +1,7 @@
+<script>
+    import Counter from "./lib/Counter.svelte";
+</script>
+
 <div>
     Hello world!
 </div>

packages/playground/start.js

@@ -20,7 +20,12 @@ function create_plugin(ssr = false) {
 					ssr ? '../svelte/src/runtime/ssr.js' : '../svelte/src/runtime/index.js'
 				);
 			} else if (id.startsWith('svelte/')) {
-				return path.resolve(__dirname, `../svelte/src/runtime/${id.slice(7)}/index.js`);
+				return path.resolve(
+					__dirname,
+					id === 'svelte/internal/tag-version'
+						? '../svelte/src/runtime/internal/tag-version.js'
+						: `../svelte/src/runtime/${id.slice(7)}/index.js`
+				);
 			}
 		},
 		transform(code, id) {

packages/svelte/package.json

@@ -56,6 +56,9 @@
       "types": "./types/index.d.ts",
       "import": "./src/runtime/store/index.js"
     },
+    "./internal/tag-version": {
+      "import": "./src/runtime/internal/tag-version.js"
+    },
     "./transition": {
       "types": "./types/index.d.ts",
       "import": "./src/runtime/transition/index.js"

packages/svelte/src/compiler/compile/index.js

@@ -30,7 +30,8 @@ const valid_options = [
 	'loopGuardTimeout',
 	'preserveComments',
 	'preserveWhitespace',
-	'cssHash'
+	'cssHash',
+	'disableVersionTagging'
 ];
 const valid_css_values = [true, false, 'injected', 'external', 'none'];
 const regex_valid_identifier = /^[a-zA-Z_$][a-zA-Z_$0-9]*$/;

packages/svelte/src/compiler/compile/render_dom/index.js

@@ -604,5 +604,17 @@ export default function dom(component, options) {
 			);
 		}
 	}
+
+	if (options.disableVersionTagging !== true) {
+		component.imports.unshift({
+			type: 'ImportDeclaration',
+			specifiers: [],
+			source: {
+				type: 'Literal',
+				value: `${options.sveltePath ?? 'svelte'}/internal/tag-version`
+			}
+		});
+	}
+
 	return { js: flatten(body), css };
 }

packages/svelte/src/compiler/interfaces.d.ts

@@ -195,6 +195,7 @@ export interface CompileOptions {
 
 	preserveComments?: boolean;
 	preserveWhitespace?: boolean;
+	disableVersionTagging?: boolean;
 }
 
 export interface ParserOptions {

packages/svelte/src/runtime/internal/tag-version.js

@@ -0,0 +1,5 @@
+import { VERSION } from '../../shared/version.js';
+
+if (typeof window !== 'undefined')
+	// @ts-ignore
+	(window.__svelte ||= { versions: new Set() }).versions.add(VERSION);

packages/svelte/test/helpers.js

@@ -134,6 +134,10 @@ export function create_loader(compileOptions, cwd) {
 					resolved = `${svelte_path}src/runtime/index.js`;
 				}
 
+				if (id === 'svelte/internal/tag-version') {
+					return `${svelte_path}src/runtime/internal/tag-version.js`;
+				}
+
 				if (id.startsWith('svelte/')) {
 					resolved = `${svelte_path}src/runtime/${id.slice(7)}/index.js`;
 				}
@@ -148,6 +152,7 @@ export function create_loader(compileOptions, cwd) {
 			// any imported Svelte components as well. A few edge cases aren't handled but also
 			// currently unused in the tests, for example `export * from`and live bindings.
 			let transformed = compiled.js.code
+				.replace(/^import ['"]([^'"]+)['"]/gm, 'await __import("$1")')
 				.replace(
 					/^import \* as (\w+) from ['"]([^'"]+)['"];?/gm,
 					'const $1 = await __import("$2");'

packages/svelte/test/js/js-output.test.js

@@ -33,7 +33,12 @@ describe('js-output', () => {
 			let actual;
 
 			try {
-				const options = Object.assign({}, config.options || {});
+				const options = Object.assign(
+					{
+						disableVersionTagging: true
+					},
+					config.options || {}
+				);
 
 				actual = svelte
 					.compile(input, options)

packages/svelte/test/runtime-browser/browser.test.js

@@ -8,6 +8,8 @@ import { pretty_print_browser_assertion, try_load_config } from '../helpers.js';
 
 const internal = path.resolve('src/runtime/internal/index.js');
 const index = path.resolve('src/runtime/index.js');
+const assert_file = path.resolve(__dirname, 'assert.js');
+const tag_version = path.resolve(__dirname, '../../src/runtime/internal/tag-version.js');
 
 /** @type {import('@playwright/test').Browser} */
 let browser;
@@ -62,7 +64,8 @@ async function run_browser_test(dir) {
 			alias: {
 				__MAIN_DOT_SVELTE__: path.resolve(__dirname, 'samples', dir, 'main.svelte'),
 				__CONFIG__: path.resolve(__dirname, 'samples', dir, '_config.js'),
-				'assert.js': path.resolve(__dirname, 'assert.js'),
+				'assert.js': assert_file,
+				'svelte/internal/tag-version': tag_version,
 				'svelte/internal': internal,
 				svelte: index
 			},
@@ -169,7 +172,8 @@ async function run_custom_elements_test(dir) {
 			entryPoints: [`${cwd}/test.js`],
 			write: false,
 			alias: {
-				'assert.js': path.resolve(__dirname, 'assert.js'),
+				'assert.js': assert_file,
+				'svelte/internal/tag-version': tag_version,
 				'svelte/internal': internal,
 				svelte: index
 			},

packages/svelte/vitest.config.js

@@ -13,6 +13,10 @@ export default defineConfig({
 					return `${__dirname}/src/runtime/index.js`;
 				}
 
+				if (id === 'svelte/internal/tag-version') {
+					return `${__dirname}/src/runtime/internal/tag-version.js`;
+				}
+
 				if (id.startsWith('svelte/')) {
 					return id.replace(/^svelte(.*)\/?$/, `${__dirname}/src/runtime/$1/index.js`);
 				}