From c2bcc743cb1857b5c2927b2df2483ed5c7fa818f Mon Sep 17 00:00:00 2001
From: Chris R <cdrx@users.noreply.github.com>
Date: Thu, 22 Dec 2022 16:04:24 +0000
Subject: [PATCH] Feat: allow access to the Durable Object's instance from
 inside a test (#385)

* feat: added `getMiniflareDurableObjectInstance()` to test environments

This allows access to the Durable Object instance for direct manipulation and testing

* Update durableobjects.module.spec.js

Co-authored-by: MrBBot <bcoll@cloudflare.com>
---
 packages/durable-objects/src/plugin.ts            |  9 +++++++++
 .../test/fixtures/durableobjects.module.spec.js   | 14 ++++++++++++++
 packages/shared-test-environment/src/globals.ts   | 12 ++++++++++++
 .../modules/durableobjects.module.spec.js         | 15 ++++++++++++++-
 4 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/packages/durable-objects/src/plugin.ts b/packages/durable-objects/src/plugin.ts
index 1dc69bc04..84972184c 100644
--- a/packages/durable-objects/src/plugin.ts
+++ b/packages/durable-objects/src/plugin.ts
@@ -15,6 +15,7 @@ import {
 import { AlarmStore } from "./alarms";
 import { DurableObjectError } from "./error";
 import {
+  DurableObject,
   DurableObjectConstructor,
   DurableObjectFactory,
   DurableObjectId,
@@ -207,6 +208,14 @@ export class DurableObjectsPlugin
     return state;
   }
 
+  async getInstance(
+    storage: StorageFactory,
+    id: DurableObjectId
+  ): Promise<DurableObject> {
+    const state = await this.getObject(storage, id);
+    return state[kInstance] as DurableObject;
+  }
+
   getNamespace(
     storage: StorageFactory,
     objectName: string
diff --git a/packages/jest-environment-miniflare/test/fixtures/durableobjects.module.spec.js b/packages/jest-environment-miniflare/test/fixtures/durableobjects.module.spec.js
index 8e929e235..e5e617619 100644
--- a/packages/jest-environment-miniflare/test/fixtures/durableobjects.module.spec.js
+++ b/packages/jest-environment-miniflare/test/fixtures/durableobjects.module.spec.js
@@ -1,3 +1,4 @@
+import { jest } from "@jest/globals";
 import { DurableObjectId } from "@miniflare/durable-objects";
 
 beforeAll(async () => {
@@ -67,3 +68,16 @@ test("Durable Objects list", async () => {
     new DurableObjectId("TEST_OBJECT", id2.toString())
   );
 });
+
+test("Access to Durable Object instance", async () => {
+  const env = getMiniflareBindings();
+  const id = env.TEST_OBJECT.idFromName("test");
+  const stub = env.TEST_OBJECT.get(id);
+  const instance = await getMiniflareDurableObjectInstance(id);
+  const fetch = jest.spyOn(instance, "fetch");
+
+  await stub.fetch(new Request("https://object/"));
+
+  expect(instance.constructor.name).toBe("TestObject");
+  expect(fetch).toHaveBeenCalled();
+});
diff --git a/packages/shared-test-environment/src/globals.ts b/packages/shared-test-environment/src/globals.ts
index 395ab24b3..6834a86b8 100644
--- a/packages/shared-test-environment/src/globals.ts
+++ b/packages/shared-test-environment/src/globals.ts
@@ -5,6 +5,7 @@ import {
   kWaitUntil,
 } from "@miniflare/core";
 import {
+  DurableObject,
   DurableObjectId,
   DurableObjectState,
   DurableObjectStorage,
@@ -32,6 +33,9 @@ declare global {
   function getMiniflareDurableObjectState(
     id: DurableObjectId
   ): Promise<DurableObjectState>;
+  function getMiniflareDurableObjectInstance(
+    id: DurableObjectId
+  ): Promise<DurableObject>;
   function runWithMiniflareDurableObjectGates<T>(
     state: DurableObjectState,
     closure: () => Awaitable<T>
@@ -56,6 +60,9 @@ export interface MiniflareEnvironmentUtilities {
   getMiniflareDurableObjectState(
     id: DurableObjectId
   ): Promise<DurableObjectState>;
+  getMiniflareDurableObjectInstance(
+    id: DurableObjectId
+  ): Promise<DurableObject>;
   runWithMiniflareDurableObjectGates<T>(
     state: DurableObjectState,
     closure: () => Awaitable<T>
@@ -91,6 +98,11 @@ export async function createMiniflareEnvironmentUtilities(
       const storage = plugin.getStorage(factory, id);
       return new DurableObjectState(id, storage);
     },
+    async getMiniflareDurableObjectInstance(id: DurableObjectId) {
+      const plugin = (await mf.getPlugins()).DurableObjectsPlugin;
+      const factory = mf.getPluginStorage("DurableObjectsPlugin");
+      return await plugin.getInstance(factory, id);
+    },
     runWithMiniflareDurableObjectGates<T>(
       state: DurableObjectState,
       closure: () => Awaitable<T>
diff --git a/packages/vitest-environment-miniflare/test/fixtures/modules/durableobjects.module.spec.js b/packages/vitest-environment-miniflare/test/fixtures/modules/durableobjects.module.spec.js
index 1e79d28d1..c78cdd26d 100644
--- a/packages/vitest-environment-miniflare/test/fixtures/modules/durableobjects.module.spec.js
+++ b/packages/vitest-environment-miniflare/test/fixtures/modules/durableobjects.module.spec.js
@@ -1,5 +1,5 @@
 import { DurableObjectId } from "@miniflare/durable-objects";
-import { beforeAll, expect, test } from "vitest";
+import { beforeAll, expect, test, vi } from "vitest";
 setupMiniflareIsolatedStorage();
 
 beforeAll(async () => {
@@ -69,3 +69,16 @@ test("Durable Objects list", async () => {
     new DurableObjectId("TEST_OBJECT", id2.toString())
   );
 });
+
+test("Access to Durable Object instance", async () => {
+  const env = getMiniflareBindings();
+  const id = env.TEST_OBJECT.idFromName("test");
+  const stub = env.TEST_OBJECT.get(id);
+  const instance = await getMiniflareDurableObjectInstance(id);
+  const fetch = vi.spyOn(instance, "fetch");
+
+  await stub.fetch(new Request("https://object/"));
+
+  expect(instance.constructor.name).toBe("TestObject");
+  expect(fetch).toHaveBeenCalled();
+});