feat: re-export built-ins from `svelte/reactivity` on the server (#10973)

* chore: re-export builtins from svelte/reactivity on the server

* changeset

* fix

.changeset/neat-files-rescue.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+feat: re-export built-ins from `svelte/reactivity` on the server

packages/svelte/package.json

@@ -64,7 +64,8 @@
     },
     "./reactivity": {
       "types": "./types/index.d.ts",
-      "default": "./src/reactivity/index.js"
+      "browser": "./src/reactivity/index-client.js",
+      "default": "./src/reactivity/index-server.js"
     },
     "./server": {
       "types": "./types/index.d.ts",

packages/svelte/scripts/generate-types.js

@@ -29,7 +29,7 @@ await createBundle({
 		[`${pkg.name}/easing`]: `${dir}/src/easing/index.js`,
 		[`${pkg.name}/legacy`]: `${dir}/src/legacy/legacy-client.js`,
 		[`${pkg.name}/motion`]: `${dir}/src/motion/public.d.ts`,
-		[`${pkg.name}/reactivity`]: `${dir}/src/reactivity/index.js`,
+		[`${pkg.name}/reactivity`]: `${dir}/src/reactivity/index-client.js`,
 		[`${pkg.name}/server`]: `${dir}/src/server/index.js`,
 		[`${pkg.name}/store`]: `${dir}/src/store/public.d.ts`,
 		[`${pkg.name}/transition`]: `${dir}/src/transition/public.d.ts`,

packages/svelte/src/reactivity/index-server.js

@@ -0,0 +1,3 @@
+export const Date = globalThis.Date;
+export const Set = globalThis.Set;
+export const Map = globalThis.Map;