From 304cda39f4de75385a0a12a67d396efad90dbc24 Mon Sep 17 00:00:00 2001
From: Maarten Manders <maarten.manders@dualinventive.com>
Date: Mon, 7 Jul 2025 13:24:45 +0200
Subject: [PATCH 01/11] Upgrade svelte to v5. Replace jest with vitest. Upgrade
 other packages

---
 .../src/svelte/generator-single-spa-svelte.js |  9 ++---
 .../src/svelte/templates/babel.config.js      | 12 -------
 .../src/svelte/templates/jest.config.js       |  9 -----
 .../src/svelte/templates/rollup.config.js     |  9 ++---
 .../src/svelte/templates/setupTests.js        |  1 +
 .../src/svelte/templates/src/App.svelte       |  4 +--
 .../src/svelte/templates/svelte.package.json  | 33 +++++++++----------
 .../src/svelte/templates/vite.config.mjs      | 17 ++++++++++
 8 files changed, 43 insertions(+), 51 deletions(-)
 delete mode 100644 packages/generator-single-spa/src/svelte/templates/babel.config.js
 delete mode 100644 packages/generator-single-spa/src/svelte/templates/jest.config.js
 create mode 100644 packages/generator-single-spa/src/svelte/templates/setupTests.js
 create mode 100644 packages/generator-single-spa/src/svelte/templates/vite.config.mjs

diff --git a/packages/generator-single-spa/src/svelte/generator-single-spa-svelte.js b/packages/generator-single-spa/src/svelte/generator-single-spa-svelte.js
index 93d0f62a..1f60cc50 100644
--- a/packages/generator-single-spa/src/svelte/generator-single-spa-svelte.js
+++ b/packages/generator-single-spa/src/svelte/generator-single-spa-svelte.js
@@ -113,13 +113,8 @@ module.exports = class SingleSpaSvelteGenerator extends PnpmGenerator {
       projectName: this.options.projectName,
     });
     this.fs.copyTpl(
-      this.templatePath(`jest.config.js`),
-      this.destinationPath(`jest.config.js`),
-      this.options
-    );
-    this.fs.copyTpl(
-      this.templatePath(`babel.config.js`),
-      this.destinationPath(`babel.config.js`),
+      this.templatePath(`vite.config.mjs`),
+      this.destinationPath(`vite.config.mjs`),
       this.options
     );
     this.fs.copyTpl(
diff --git a/packages/generator-single-spa/src/svelte/templates/babel.config.js b/packages/generator-single-spa/src/svelte/templates/babel.config.js
deleted file mode 100644
index 392abb66..00000000
--- a/packages/generator-single-spa/src/svelte/templates/babel.config.js
+++ /dev/null
@@ -1,12 +0,0 @@
-module.exports = {
-  presets: [
-    [
-      "@babel/preset-env",
-      {
-        targets: {
-          node: "current",
-        },
-      },
-    ],
-  ],
-};
diff --git a/packages/generator-single-spa/src/svelte/templates/jest.config.js b/packages/generator-single-spa/src/svelte/templates/jest.config.js
deleted file mode 100644
index 5326bb08..00000000
--- a/packages/generator-single-spa/src/svelte/templates/jest.config.js
+++ /dev/null
@@ -1,9 +0,0 @@
-module.exports = {
-  testEnvironment: "jsdom",
-  transform: {
-    "^.+\\.svelte$": "svelte-jester",
-    "^.+\\.js$": "babel-jest",
-  },
-  moduleFileExtensions: ["js", "svelte"],
-  setupFilesAfterEnv: ["@testing-library/jest-dom"],
-};
diff --git a/packages/generator-single-spa/src/svelte/templates/rollup.config.js b/packages/generator-single-spa/src/svelte/templates/rollup.config.js
index 57a9d591..b11b100b 100644
--- a/packages/generator-single-spa/src/svelte/templates/rollup.config.js
+++ b/packages/generator-single-spa/src/svelte/templates/rollup.config.js
@@ -2,7 +2,8 @@ import svelte from "rollup-plugin-svelte";
 import resolve from "@rollup/plugin-node-resolve";
 import commonjs from "@rollup/plugin-commonjs";
 import livereload from "rollup-plugin-livereload";
-import { terser } from "rollup-plugin-terser";
+import { minify } from "rollup-plugin-esbuild-minify";
+import { spawn } from "child_process";
 
 const production = !process.env.ROLLUP_WATCH;
 
@@ -10,7 +11,7 @@ export default {
   input: "src/<%= orgName %>-<%= projectName %>.js",
   output: {
     sourcemap: true,
-    format: "system",
+    format: "esm",
     name: null, // ensure anonymous System.register
     file: "dist/<%= orgName %>-<%= projectName %>.js",
   },
@@ -43,7 +44,7 @@ export default {
 
     // If we're building for production (npm run build
     // instead of npm run dev), minify
-    production && terser(),
+    production && minify(),
   ],
   watch: {
     clearScreen: false,
@@ -58,7 +59,7 @@ function serve() {
       if (!started) {
         started = true;
 
-        require("child_process").spawn("npm", ["run", "serve", "--", "--dev"], {
+        spawn("npm", ["run", "serve", "--", "--dev"], {
           stdio: ["ignore", "inherit", "inherit"],
           shell: true,
         });
diff --git a/packages/generator-single-spa/src/svelte/templates/setupTests.js b/packages/generator-single-spa/src/svelte/templates/setupTests.js
new file mode 100644
index 00000000..f149f27a
--- /dev/null
+++ b/packages/generator-single-spa/src/svelte/templates/setupTests.js
@@ -0,0 +1 @@
+import "@testing-library/jest-dom/vitest";
diff --git a/packages/generator-single-spa/src/svelte/templates/src/App.svelte b/packages/generator-single-spa/src/svelte/templates/src/App.svelte
index 8b58acfb..57f71b07 100644
--- a/packages/generator-single-spa/src/svelte/templates/src/App.svelte
+++ b/packages/generator-single-spa/src/svelte/templates/src/App.svelte
@@ -1,5 +1,5 @@
-<script>
-  export let name;
+<script lang="ts">
+  let { name } = $props();
 </script>
 
 <style>
diff --git a/packages/generator-single-spa/src/svelte/templates/svelte.package.json b/packages/generator-single-spa/src/svelte/templates/svelte.package.json
index 42975291..d516eedc 100644
--- a/packages/generator-single-spa/src/svelte/templates/svelte.package.json
+++ b/packages/generator-single-spa/src/svelte/templates/svelte.package.json
@@ -5,29 +5,28 @@
     "build:rollup": "rollup -c",
     "start": "rollup -c -w",
     "serve": "sirv dist -c",
-    "test": "jest",
+    "test": "vitest",
     "prepare": "husky install",
     "format": "prettier --write --plugin-search-dir=. .",
     "check-format": "prettier --plugin-search-dir=. --check ."
   },
   "devDependencies": {
-    "@babel/core": "^7.23.3",
-    "@babel/preset-env": "^7.23.3",
-    "@rollup/plugin-commonjs": "^20.0.0",
-    "@rollup/plugin-node-resolve": "^13.0.4",
-    "@testing-library/jest-dom": "^5.17.0",
-    "@testing-library/svelte": "^3.0.3",
-    "babel-jest": "^27.5.1",
-    "concurrently": "^6.2.1",
-    "jest": "^27.5.1",
-    "prettier": "^2.3.2",
-    "prettier-plugin-svelte": "^2.3.1",
-    "rollup": "^2.56.3",
+    "@babel/core": "^7.27.7",
+    "@babel/preset-env": "^7.27.2",
+    "@rollup/plugin-commonjs": "^28.0.6",
+    "@rollup/plugin-node-resolve": "^16.0.1",
+    "@sveltejs/vite-plugin-svelte": "^5.1.0",
+    "@testing-library/jest-dom": "^6.6.3",
+    "@testing-library/svelte": "^5.2.8",
+    "concurrently": "^9.2.0",
+    "prettier": "^3.6.2",
+    "prettier-plugin-svelte": "^3.4.0",
+    "rollup": "^4.44.1",
+    "rollup-plugin-esbuild-minify": "^1.3.0",
     "rollup-plugin-livereload": "^2.0.5",
-    "rollup-plugin-svelte": "^7.1.0",
-    "rollup-plugin-terser": "^7.0.2",
-    "svelte": "^3.42.3",
-    "svelte-jester": "^2.0.0"
+    "rollup-plugin-svelte": "^7.2.2",
+    "svelte": "^5.34.9",
+    "vitest": "^3.2.4"
   },
   "dependencies": {
     "single-spa-svelte": "^2.1.1",
diff --git a/packages/generator-single-spa/src/svelte/templates/vite.config.mjs b/packages/generator-single-spa/src/svelte/templates/vite.config.mjs
new file mode 100644
index 00000000..785f7628
--- /dev/null
+++ b/packages/generator-single-spa/src/svelte/templates/vite.config.mjs
@@ -0,0 +1,17 @@
+import { defineConfig } from "vite";
+import { svelte } from "@sveltejs/vite-plugin-svelte";
+
+// https://vitejs.dev/config/
+export default defineConfig({
+  plugins: [svelte()],
+  test: {
+    globals: true,
+    environment: "jsdom",
+    setupFiles: ["./setupTests.js"],
+  },
+  resolve: process.env.VITEST
+    ? {
+        conditions: ["browser"],
+      }
+    : undefined,
+});

From bb6333bd5ec63ad56c27bd43866f3664b9854e93 Mon Sep 17 00:00:00 2001
From: Maarten Manders <maarten.manders@dualinventive.com>
Date: Mon, 7 Jul 2025 13:51:53 +0200
Subject: [PATCH 02/11] Fix svelte settings

---
 .../src/svelte/templates/rollup.config.js                   | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/packages/generator-single-spa/src/svelte/templates/rollup.config.js b/packages/generator-single-spa/src/svelte/templates/rollup.config.js
index b11b100b..dc197cbe 100644
--- a/packages/generator-single-spa/src/svelte/templates/rollup.config.js
+++ b/packages/generator-single-spa/src/svelte/templates/rollup.config.js
@@ -17,8 +17,10 @@ export default {
   },
   plugins: [
     svelte({
-      // enable run-time checks when not in production
-      dev: !production,
+      compilerOptions: {
+        // enable run-time checks when not in production
+        dev: !production,
+      },
 
       emitCss: false,
     }),

From 9d67a360907b7cb6ef94358c6be9c88ab799f91c Mon Sep 17 00:00:00 2001
From: Maarten Manders <maarten.manders@dualinventive.com>
Date: Mon, 7 Jul 2025 13:55:38 +0200
Subject: [PATCH 03/11] Set type to module to fix overhead warning

---
 .../src/svelte/templates/svelte.package.json                     | 1 +
 1 file changed, 1 insertion(+)

diff --git a/packages/generator-single-spa/src/svelte/templates/svelte.package.json b/packages/generator-single-spa/src/svelte/templates/svelte.package.json
index d516eedc..37569a06 100644
--- a/packages/generator-single-spa/src/svelte/templates/svelte.package.json
+++ b/packages/generator-single-spa/src/svelte/templates/svelte.package.json
@@ -1,5 +1,6 @@
 {
   "name": "<%= name %>",
+  "type": "module",
   "scripts": {
     "build": "concurrently <%- packageManager %>:build:*",
     "build:rollup": "rollup -c",

From f9d2fcdb83c7485d83c5c67dcb68632c86236c5c Mon Sep 17 00:00:00 2001
From: Maarten Manders <maarten.manders@dualinventive.com>
Date: Thu, 17 Jul 2025 14:54:53 +0200
Subject: [PATCH 04/11] Add required mount and unmount options.

---
 packages/generator-single-spa/src/svelte/templates/src/main.js | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/packages/generator-single-spa/src/svelte/templates/src/main.js b/packages/generator-single-spa/src/svelte/templates/src/main.js
index 3c07de72..65c0ff5f 100644
--- a/packages/generator-single-spa/src/svelte/templates/src/main.js
+++ b/packages/generator-single-spa/src/svelte/templates/src/main.js
@@ -1,8 +1,11 @@
 import singleSpaSvelte from "single-spa-svelte";
+import { mount as originalMount, unmount as originalUnmount } from "svelte";
 import App from "./App.svelte";
 
 const svelteLifecycles = singleSpaSvelte({
   component: App,
+  mount: originalMount,
+  unmount: originalUnmount,
 });
 
 export const { bootstrap, mount, unmount } = svelteLifecycles;

From faae69b3b1ee2c2380ff917c84b5c6b4c2f860e0 Mon Sep 17 00:00:00 2001
From: Maarten Manders <maarten.manders@dualinventive.com>
Date: Thu, 17 Jul 2025 14:55:25 +0200
Subject: [PATCH 05/11] Remove babel dependencies. Move svelte from dev
 dependencies.

---
 .../src/svelte/templates/svelte.package.json                | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/packages/generator-single-spa/src/svelte/templates/svelte.package.json b/packages/generator-single-spa/src/svelte/templates/svelte.package.json
index 37569a06..abc0ff46 100644
--- a/packages/generator-single-spa/src/svelte/templates/svelte.package.json
+++ b/packages/generator-single-spa/src/svelte/templates/svelte.package.json
@@ -12,8 +12,6 @@
     "check-format": "prettier --plugin-search-dir=. --check ."
   },
   "devDependencies": {
-    "@babel/core": "^7.27.7",
-    "@babel/preset-env": "^7.27.2",
     "@rollup/plugin-commonjs": "^28.0.6",
     "@rollup/plugin-node-resolve": "^16.0.1",
     "@sveltejs/vite-plugin-svelte": "^5.1.0",
@@ -26,11 +24,11 @@
     "rollup-plugin-esbuild-minify": "^1.3.0",
     "rollup-plugin-livereload": "^2.0.5",
     "rollup-plugin-svelte": "^7.2.2",
-    "svelte": "^5.34.9",
     "vitest": "^3.2.4"
   },
   "dependencies": {
     "single-spa-svelte": "^2.1.1",
-    "sirv-cli": "^1.0.14"
+    "sirv-cli": "^1.0.14",
+    "svelte": "^5.34.9"
   }
 }

From 99bd7d6236283bcfda6921719b64b19629986b32 Mon Sep 17 00:00:00 2001
From: Maarten Manders <maarten.manders@dualinventive.com>
Date: Thu, 17 Jul 2025 14:55:43 +0200
Subject: [PATCH 06/11] Add changeset

---
 .changeset/pink-dodos-suffer.md | 7 +++++++
 1 file changed, 7 insertions(+)
 create mode 100644 .changeset/pink-dodos-suffer.md

diff --git a/.changeset/pink-dodos-suffer.md b/.changeset/pink-dodos-suffer.md
new file mode 100644
index 00000000..520f9503
--- /dev/null
+++ b/.changeset/pink-dodos-suffer.md
@@ -0,0 +1,7 @@
+---
+"generator-single-spa": major
+---
+
+- Breaking: Upgrade svelte to v5. Mount and unmount need to be passed to the `singleSpaSvelte` function.
+- Breaking: Rollup now outputs using the ESM format rather than the System format.
+- Replace jest with vitest to simplify test setup.

From 2356c3ef59ac723b319f27883427cb98e74726ad Mon Sep 17 00:00:00 2001
From: Maarten Manders <maarten.manders@dualinventive.com>
Date: Thu, 17 Jul 2025 15:00:54 +0200
Subject: [PATCH 07/11] Update changeset

---
 .changeset/pink-dodos-suffer.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.changeset/pink-dodos-suffer.md b/.changeset/pink-dodos-suffer.md
index 520f9503..000fc35c 100644
--- a/.changeset/pink-dodos-suffer.md
+++ b/.changeset/pink-dodos-suffer.md
@@ -4,4 +4,5 @@
 
 - Breaking: Upgrade svelte to v5. Mount and unmount need to be passed to the `singleSpaSvelte` function.
 - Breaking: Rollup now outputs using the ESM format rather than the System format.
+- Breaking: Set `"type": "module"` in package.json to avoid performance overhead during rollup.
 - Replace jest with vitest to simplify test setup.

From 798dc809a5d82d7908e89c4675a4f86e0c18d4fc Mon Sep 17 00:00:00 2001
From: Maarten Manders <maarten.manders@dualinventive.com>
Date: Fri, 18 Jul 2025 08:35:20 +0200
Subject: [PATCH 08/11] Remove typescript tag

---
 .../generator-single-spa/src/svelte/templates/src/App.svelte    | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/generator-single-spa/src/svelte/templates/src/App.svelte b/packages/generator-single-spa/src/svelte/templates/src/App.svelte
index 57f71b07..e334b79f 100644
--- a/packages/generator-single-spa/src/svelte/templates/src/App.svelte
+++ b/packages/generator-single-spa/src/svelte/templates/src/App.svelte
@@ -1,4 +1,4 @@
-<script lang="ts">
+<script>
   let { name } = $props();
 </script>
 

From 347b129182e4ce083865d831fdca66f79701ee06 Mon Sep 17 00:00:00 2001
From: Maarten Manders <maarten.manders@dualinventive.com>
Date: Fri, 10 Oct 2025 13:17:45 +0200
Subject: [PATCH 09/11] Add missing jsdom dependency.

---
 .../src/svelte/templates/svelte.package.json                   | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/packages/generator-single-spa/src/svelte/templates/svelte.package.json b/packages/generator-single-spa/src/svelte/templates/svelte.package.json
index abc0ff46..3600ed65 100644
--- a/packages/generator-single-spa/src/svelte/templates/svelte.package.json
+++ b/packages/generator-single-spa/src/svelte/templates/svelte.package.json
@@ -24,7 +24,8 @@
     "rollup-plugin-esbuild-minify": "^1.3.0",
     "rollup-plugin-livereload": "^2.0.5",
     "rollup-plugin-svelte": "^7.2.2",
-    "vitest": "^3.2.4"
+    "vitest": "^3.2.4",
+    "jsdom": "^27.0.0"
   },
   "dependencies": {
     "single-spa-svelte": "^2.1.1",

From 05383f39168823bc6ab2cdfaa7ed18bb6a92b3af Mon Sep 17 00:00:00 2001
From: Maarten Manders <maarten.manders@dualinventive.com>
Date: Fri, 10 Oct 2025 13:18:12 +0200
Subject: [PATCH 10/11] Add missing copy command for setupTests.js

---
 .../src/svelte/generator-single-spa-svelte.js                | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/packages/generator-single-spa/src/svelte/generator-single-spa-svelte.js b/packages/generator-single-spa/src/svelte/generator-single-spa-svelte.js
index 1f60cc50..2db50af5 100644
--- a/packages/generator-single-spa/src/svelte/generator-single-spa-svelte.js
+++ b/packages/generator-single-spa/src/svelte/generator-single-spa-svelte.js
@@ -117,6 +117,11 @@ module.exports = class SingleSpaSvelteGenerator extends PnpmGenerator {
       this.destinationPath(`vite.config.mjs`),
       this.options
     );
+    this.fs.copyTpl(
+      this.templatePath(`setupTests.js`),
+      this.destinationPath(`setupTests.js`),
+      this.options
+    );
     this.fs.copyTpl(
       this.templatePath(`src/App.svelte`),
       this.destinationPath(`src/App.svelte`),

From 4e20c7a21340347d455f1c6c01bbafe981681ac3 Mon Sep 17 00:00:00 2001
From: Maarten Manders <maarten.manders@dualinventive.com>
Date: Fri, 10 Oct 2025 13:18:37 +0200
Subject: [PATCH 11/11] Change to use @single-spa/svelte

---
 packages/generator-single-spa/src/svelte/templates/src/main.js  | 2 +-
 .../src/svelte/templates/svelte.package.json                    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/generator-single-spa/src/svelte/templates/src/main.js b/packages/generator-single-spa/src/svelte/templates/src/main.js
index 65c0ff5f..ad908870 100644
--- a/packages/generator-single-spa/src/svelte/templates/src/main.js
+++ b/packages/generator-single-spa/src/svelte/templates/src/main.js
@@ -1,4 +1,4 @@
-import singleSpaSvelte from "single-spa-svelte";
+import singleSpaSvelte from "@single-spa/svelte";
 import { mount as originalMount, unmount as originalUnmount } from "svelte";
 import App from "./App.svelte";
 
diff --git a/packages/generator-single-spa/src/svelte/templates/svelte.package.json b/packages/generator-single-spa/src/svelte/templates/svelte.package.json
index 3600ed65..4eaf3d9e 100644
--- a/packages/generator-single-spa/src/svelte/templates/svelte.package.json
+++ b/packages/generator-single-spa/src/svelte/templates/svelte.package.json
@@ -28,7 +28,7 @@
     "jsdom": "^27.0.0"
   },
   "dependencies": {
-    "single-spa-svelte": "^2.1.1",
+    "@single-spa/svelte": "^3.0.0-beta.0",
     "sirv-cli": "^1.0.14",
     "svelte": "^5.34.9"
   }