test: refactor connection handoff tests with enhanced spy utility

packages/client/lib/tests/test-scenario/connection-handoff.e2e.ts

@@ -6,17 +6,56 @@ import {
   getEnvConfig,
   RedisConnectionConfig,
 } from "./test-scenario.util";
-import { createClient } from "../../..";
+import { createClient, RedisClientOptions } from "../../..";
 import { before } from "mocha";
-import { spy } from "sinon";
+import Sinon, { SinonSpy, spy, stub } from "sinon";
 import assert from "node:assert";
-import net from "node:net";
+
+/**
+ * Creates a spy on a duplicated client method
+ * @param client - The Redis client instance
+ * @param funcName - The name of the method to spy on
+ * @returns Object containing the promise that resolves with the spy and restore function
+ */
+const spyOnTemporaryClientInstanceMethod = (
+  client: ReturnType<typeof createClient<any, any, any, any>>,
+  methodName: string
+) => {
+  const { promise, resolve } = (
+    Promise as typeof Promise & {
+      withResolvers: () => {
+        promise: Promise<{ spy: SinonSpy<any[], any>; restore: () => void }>;
+        resolve: (value: any) => void;
+      };
+    }
+  ).withResolvers();
+
+  const originalDuplicate = client.duplicate.bind(client);
+
+  const duplicateStub: Sinon.SinonStub<any[], any> = stub(
+    // Temporary clients (in the context of hitless upgrade)
+    // are created by calling the duplicate method on the client.
+    Object.getPrototypeOf(client),
+    "duplicate"
+  ).callsFake((opts) => {
+    const tmpClient = originalDuplicate(opts);
+    resolve({
+      spy: spy(tmpClient, methodName),
+      restore: duplicateStub.restore,
+    });
+
+    return tmpClient;
+  });
+
+  return {
+    getSpy: () => promise,
+  };
+};
 
 describe("Connection Handoff", () => {
   let clientConfig: RedisConnectionConfig;
   let client: ReturnType<typeof createClient<any, any, any, any>>;
   let faultInjectorClient: FaultInjectorClient;
-  let connectSpy = spy(net, "createConnection");
 
   before(() => {
     const envConfig = getEnvConfig();
@@ -28,62 +67,110 @@ describe("Connection Handoff", () => {
     clientConfig = getDatabaseConfig(redisConfig);
   });
 
-  beforeEach(async () => {
-    connectSpy.resetHistory();
-
-    client = await createTestClient(clientConfig);
-
-    await client.flushAll();
-  });
-
-  afterEach(() => {
+  afterEach(async () => {
     if (client && client.isOpen) {
+      await client.flushAll();
       client.destroy();
     }
   });
 
-  describe("New Connection Establishment", () => {
-    it("should establish new connection", async () => {
-      assert.equal(connectSpy.callCount, 1);
-
-      const { action_id: lowTimeoutBindAndMigrateActionId } =
-        await faultInjectorClient.migrateAndBindAction({
-          bdbId: clientConfig.bdbId,
-          clusterIndex: 0,
-        });
-
-      await faultInjectorClient.waitForAction(lowTimeoutBindAndMigrateActionId);
-
-      assert.equal(connectSpy.callCount, 2);
-    });
+  describe("New Connection Establishment & Traffic Resumption", () => {
+    const cases: Array<{
+      name: string;
+      clientOptions: Partial<RedisClientOptions>;
+    }> = [
+      {
+        name: "default options",
+        clientOptions: {},
+      },
+      {
+        name: "external-ip",
+        clientOptions: {
+          maintMovingEndpointType: "external-ip",
+        },
+      },
+      {
+        name: "external-fqdn",
+        clientOptions: {
+          maintMovingEndpointType: "external-fqdn",
+        },
+      },
+      {
+        name: "auto",
+        clientOptions: {
+          maintMovingEndpointType: "auto",
+        },
+      },
+      {
+        name: "none",
+        clientOptions: {
+          maintMovingEndpointType: "none",
+        },
+      },
+    ];
+
+    for (const { name, clientOptions } of cases) {
+      it.only(`should establish new connection and resume traffic afterwards - ${name}`, async () => {
+        client = await createTestClient(clientConfig, clientOptions);
+
+        const spyObject = spyOnTemporaryClientInstanceMethod(client, "connect");
+
+        // PART 1 Establish initial connection
+        const { action_id: lowTimeoutBindAndMigrateActionId } =
+          await faultInjectorClient.migrateAndBindAction({
+            bdbId: clientConfig.bdbId,
+            clusterIndex: 0,
+          });
+
+        await faultInjectorClient.waitForAction(
+          lowTimeoutBindAndMigrateActionId
+        );
+
+        const spyResult = await spyObject.getSpy();
+
+        assert.strictEqual(spyResult.spy.callCount, 1);
+
+        // PART 2 Verify traffic resumption
+        const currentTime = Date.now().toString();
+        await client.set("key", currentTime);
+        const result = await client.get("key");
+
+        assert.strictEqual(result, currentTime);
+
+        spyResult.restore();
+      });
+    }
   });
 
   describe("TLS Connection Handoff", () => {
-    it("TODO receiveMessagesWithTLSEnabledTest", async () => {
+    it.skip("TODO receiveMessagesWithTLSEnabledTest", async () => {
       //
     });
-    it("TODO connectionHandoffWithStaticInternalNameTest", async () => {
+    it.skip("TODO connectionHandoffWithStaticInternalNameTest", async () => {
       //
     });
-    it("TODO connectionHandoffWithStaticExternalNameTest", async () => {
+    it.skip("TODO connectionHandoffWithStaticExternalNameTest", async () => {
       //
     });
   });
 
-  describe("Traffic Resumption", () => {
-    it("Traffic resumed after handoff", async () => {
-      const { action_id } = await faultInjectorClient.migrateAndBindAction({
-        bdbId: clientConfig.bdbId,
-        clusterIndex: 0,
-      });
+  describe("Connection Cleanup", () => {
+    it("should shut down old connection", async () => {
+      const spyObject = spyOnTemporaryClientInstanceMethod(client, "destroy");
+
+      const { action_id: lowTimeoutBindAndMigrateActionId } =
+        await faultInjectorClient.migrateAndBindAction({
+          bdbId: clientConfig.bdbId,
+          clusterIndex: 0,
+        });
+
+      await faultInjectorClient.waitForAction(lowTimeoutBindAndMigrateActionId);
 
-      await faultInjectorClient.waitForAction(action_id);
+      const spyResult = await spyObject.getSpy();
 
-      const currentTime = Date.now().toString();
-      await client.set("key", currentTime);
-      const result = await client.get("key");
+      assert.equal(spyResult.spy.callCount, 1);
 
-      assert.strictEqual(result, currentTime);
+      spyResult.restore();
     });
   });
 });