feat: implement adapter.emulate

packages/adapter-cloudflare-workers/index.js

@@ -4,6 +4,7 @@ import { execSync } from 'node:child_process';
 import esbuild from 'esbuild';
 import toml from '@iarna/toml';
 import { fileURLToPath } from 'node:url';
+import { getPlatformProxy } from 'wrangler';
 
 /**
  * @typedef {{
@@ -140,6 +141,34 @@ export default function ({ config = 'wrangler.toml' } = {}) {
 			const bucket_dir = `${site.bucket}${builder.config.kit.paths.base}`;
 			builder.writeClient(bucket_dir);
 			builder.writePrerendered(bucket_dir);
+		},
+
+		async emulate() {
+			const proxy = await getPlatformProxy();
+			const platform = /** @type {App.Platform} */ ({
+				env: proxy.env,
+				context: proxy.ctx,
+				caches: proxy.caches,
+				cf: proxy.cf
+			});
+
+			/** @type {Record<string, any>} */
+			const env = {};
+			const prerender_platform = /** @type {App.Platform} */ (/** @type {unknown} */ ({ env }));
+
+			for (const key in proxy.env) {
+				Object.defineProperty(env, key, {
+					get: () => {
+						throw new Error(`Cannot access platform.env.${key} in a prerenderable route`);
+					}
+				});
+			}
+
+			return {
+				platform: ({ prerender }) => {
+					return prerender ? prerender_platform : platform;
+				}
+			};
 		}
 	};
 }

packages/adapter-cloudflare-workers/package.json

@@ -27,7 +27,7 @@
 	"scripts": {
 		"lint": "prettier --check .",
 		"format": "pnpm lint --write",
-		"check": "tsc"
+		"check": "tsc --skipLibCheck"
 	},
 	"dependencies": {
 		"@cloudflare/workers-types": "^4.20231121.0",
@@ -41,6 +41,7 @@
 		"typescript": "^5.3.3"
 	},
 	"peerDependencies": {
-		"@sveltejs/kit": "^2.0.0"
+		"@sveltejs/kit": "^2.0.0",
+		"wrangler": "^3.28.4"
 	}
 }

packages/adapter-cloudflare/ambient.d.ts

@@ -1,12 +1,12 @@
-import { Cache, CacheStorage, IncomingRequestCfProperties } from '@cloudflare/workers-types';
+import { CacheStorage, IncomingRequestCfProperties } from '@cloudflare/workers-types';
 
 declare global {
 	namespace App {
 		export interface Platform {
-			context?: {
+			context: {
 				waitUntil(promise: Promise<any>): void;
 			};
-			caches?: CacheStorage & { default: Cache };
+			caches: CacheStorage;
 			cf?: IncomingRequestCfProperties;
 		}
 	}

packages/adapter-cloudflare/index.js

@@ -2,6 +2,7 @@ import { writeFileSync } from 'node:fs';
 import * as path from 'node:path';
 import { fileURLToPath } from 'node:url';
 import * as esbuild from 'esbuild';
+import { getPlatformProxy } from 'wrangler';
 
 // list from https://developers.cloudflare.com/workers/runtime-apis/nodejs/
 const compatible_node_modules = [
@@ -124,6 +125,33 @@ export default function (options = {}) {
 					}`
 				);
 			}
+		},
+		async emulate() {
+			const proxy = await getPlatformProxy();
+			const platform = /** @type {App.Platform} */ ({
+				env: proxy.env,
+				context: proxy.ctx,
+				caches: proxy.caches,
+				cf: proxy.cf
+			});
+
+			/** @type {Record<string, any>} */
+			const env = {};
+			const prerender_platform = /** @type {App.Platform} */ (/** @type {unknown} */ ({ env }));
+
+			for (const key in proxy.env) {
+				Object.defineProperty(env, key, {
+					get: () => {
+						throw new Error(`Cannot access platform.env.${key} in a prerenderable route`);
+					}
+				});
+			}
+
+			return {
+				platform: ({ prerender }) => {
+					return prerender ? prerender_platform : platform;
+				}
+			};
 		}
 	};
 }

packages/adapter-cloudflare/package.json

@@ -43,7 +43,8 @@
 		"typescript": "^5.3.3"
 	},
 	"peerDependencies": {
-		"@sveltejs/kit": "^2.0.0"
+		"@sveltejs/kit": "^2.0.0",
+		"wrangler": "^3.28.4"
 	},
 	"publishConfig": {
 		"access": "public"