introduce devPlatform kit configuration

Author: dario-piotrowicz

packages/kit/src/core/config/options.js

@@ -280,7 +280,9 @@ const options = object(
 version: object({
 name: string(Date.now().toString()),
 pollInterval: number(0)
-})
+}),
+
+devPlatform: object({}, true),
 })
 },
 true

packages/kit/src/exports/public.d.ts

@@ -630,6 +630,12 @@ export interface KitConfig {
  */
 pollInterval?: number;
 };
+/**
+ * Platform object to be used during development, allowing the simulation of a production platform during local development.
+ *
+ * @default undefined
+ */
+devPlatform?: unknown;
 }
 
 /**

packages/kit/src/exports/vite/dev/index.js

@@ -513,7 +513,8 @@ export async function dev(vite, vite_config, svelte_config) {
 if (remoteAddress) return remoteAddress;
 throw new Error('Could not determine clientAddress');
 },
-read: (file) => fs.readFileSync(path.join(svelte_config.kit.files.assets, file))
+read: (file) => fs.readFileSync(path.join(svelte_config.kit.files.assets, file)),
+platform: svelte_config.kit.devPlatform,
 });
 
 if (rendered.status === 404) {

packages/kit/src/exports/vite/preview/index.js

@@ -188,7 +188,8 @@ export async function preview(vite, vite_config, svelte_config) {
 if (remoteAddress) return remoteAddress;
 throw new Error('Could not determine clientAddress');
 },
-read: (file) => fs.readFileSync(join(svelte_config.kit.files.assets, file))
+read: (file) => fs.readFileSync(join(svelte_config.kit.files.assets, file)),
+platform: svelte_config.kit.devPlatform,
 })
 );
 });

packages/kit/types/index.d.ts

@@ -610,6 +610,12 @@ declare module '@sveltejs/kit' {
  */
 pollInterval?: number;
 };
+/**
+ * Platform object to be used during development, allowing the simulation of a production platform during local development.
+ *
+ * @default undefined
+ */
+devPlatform?: unknown;
 }
 
 /**