feat(cloudflare): add durable.bindingName config

src/build/config.ts

@@ -21,6 +21,8 @@ export function baseBuildConfig(nitro: Nitro) {
     baseURL: nitro.options.baseURL,
     _asyncContext: nitro.options.experimental.asyncContext,
     _tasks: nitro.options.experimental.tasks,
+    _durableBindingName:
+      nitro.options.cloudflare?.durable?.bindingName || "$DurableObject",
   };
 
   const replacements = {

src/presets/cloudflare/runtime/cloudflare-durable.ts

@@ -9,7 +9,7 @@ import { isPublicAssetURL } from "#nitro/virtual/public-assets";
 import { resolveWebsocketHooks } from "#nitro/runtime/app";
 import { hasWebSocket } from "#nitro/virtual/feature-flags";
 
-const DURABLE_BINDING = "$DurableObject";
+const DURABLE_BINDING = import.meta._durableBindingName || "$DurableObject";
 const DURABLE_INSTANCE = "server";
 
 interface Env {

src/presets/cloudflare/types.ts

@@ -97,6 +97,20 @@ export interface CloudflareOptions {
    * Custom Cloudflare exports additional classes such as WorkflowEntrypoint.
    */
   exports?: string;
+
+  /**
+   * Options for Durable Objects.
+   */
+  durable?: {
+    /**
+     * The binding name for the Durable Object used by `defineWebSocketHandler`.
+     *
+     * Must match the `name` field in your wrangler.json `durable_objects.bindings` config.
+     *
+     * @default "$DurableObject"
+     */
+    bindingName?: string;
+  };
 }
 
 type DurableObjectState = ConstructorParameters<typeof DurableObject>[0];

src/presets/cloudflare/utils.ts

@@ -328,6 +328,23 @@ export async function writeWranglerConfig(
         globs: ["**/*.mjs", "**/*.js"],
       });
     }
+
+    // Durable Objects config for cloudflare-durable preset
+    if (nitro.options.preset === "cloudflare-durable") {
+      const bindingName =
+        nitro.options.cloudflare?.durable?.bindingName || "$DurableObject";
+      wranglerConfig.durable_objects ??= { bindings: [] };
+      wranglerConfig.durable_objects.bindings ??= [];
+      const hasBinding = wranglerConfig.durable_objects.bindings.some(
+        (b) => b.name === bindingName && b.class_name === "$DurableObject"
+      );
+      if (!hasBinding) {
+        wranglerConfig.durable_objects.bindings.push({
+          name: bindingName,
+          class_name: "$DurableObject",
+        });
+      }
+    }
   }
 
   // Write wrangler.json

src/types/global.ts

@@ -11,6 +11,7 @@ export interface NitroImportMeta {
   runtimeConfig?: Record<string, any>;
   _asyncContext?: boolean;
   _tasks?: boolean;
+  _durableBindingName?: string;
 }
 
 declare global {

test/fixture/nitro.config.ts

@@ -140,6 +140,9 @@ export default defineConfig({
     wrangler: {
       compatibility_date: "2024-01-01",
     },
+    durable: {
+      bindingName: "MyCustomDO",
+    },
   },
   typescript: {
     generateRuntimeConfigTypes: true,

test/presets/cloudflare-durable.test.ts

@@ -0,0 +1,26 @@
+import { promises as fsp } from "node:fs";
+import { resolve } from "pathe";
+import { describe, expect, it } from "vitest";
+
+import { setupTest } from "../tests.ts";
+
+describe("nitro:preset:cloudflare-durable", async () => {
+  const ctx = await setupTest("cloudflare-durable");
+
+  it("should use custom durable binding name from config", async () => {
+    const entry = await fsp.readFile(
+      resolve(ctx.outDir, "server", "chunks", "nitro", "nitro.mjs"),
+      "utf8"
+    );
+    // Check that custom binding name is used instead of default $DurableObject
+    expect(entry).toContain("MyCustomDO");
+  });
+
+  it("should export $DurableObject class", async () => {
+    const entry = await fsp.readFile(
+      resolve(ctx.outDir, "server", "index.mjs"),
+      "utf8"
+    );
+    expect(entry).toMatch(/\$DurableObject/);
+  });
+});