introduce devPlatform kit configuration

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

@@ -270,7 +270,9 @@ const options = object(
 			version: object({
 				name: string(Date.now().toString()),
 				pollInterval: number(0)
-			})
+			}),
+
+			devPlatform: object({}, true),
 		})
 	},
 	true

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

@@ -657,6 +657,12 @@ 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

@@ -529,7 +529,8 @@ export async function dev(vite, vite_config, svelte_config) {
 					read: (file) => fs.readFileSync(path.join(svelte_config.kit.files.assets, file)),
 					before_handle: (event, config, prerender) => {
 						async_local_storage.enterWith({ event, config, prerender });
-					}
+					},
+					platform: svelte_config.kit.devPlatform,
 				});
 
 				if (rendered.status === 404) {

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

@@ -191,7 +191,8 @@ 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

@@ -639,6 +639,12 @@ 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;
 	}
 
 	/**