From e2a78cb60773a7a17f3a204e9826b3507d20c4d4 Mon Sep 17 00:00:00 2001
From: Adan <adanwat@amazon.com>
Date: Wed, 21 Feb 2024 16:22:07 +0000
Subject: [PATCH] Node: added echo command.

---
 node/src/BaseClient.ts      | 11 +++++++++++
 node/src/Commands.ts        |  7 +++++++
 node/src/Transaction.ts     | 12 ++++++++++++
 node/tests/SharedTests.ts   | 11 +++++++++++
 node/tests/TestUtilities.ts |  2 ++
 5 files changed, 43 insertions(+)

diff --git a/node/src/BaseClient.ts b/node/src/BaseClient.ts
index a73c40f47e..ff86a54263 100644
--- a/node/src/BaseClient.ts
+++ b/node/src/BaseClient.ts
@@ -18,6 +18,7 @@ import {
     createDecr,
     createDecrBy,
     createDel,
+    createEcho,
     createExists,
     createExpire,
     createExpireAt,
@@ -1138,6 +1139,16 @@ export class BaseClient {
         return this.createWritePromise(createZpopmax(key, count));
     }
 
+    /** Echoes the provided `message` back.
+     * See https://redis.io/commands/echo for more details.
+     * 
+     * @param message - The message to be echoed back.
+     * @returns The provided `message`.
+     */
+    public echo(message: string): Promise<string> {
+        return this.createWritePromise(createEcho(message));
+    }
+
     private readonly MAP_READ_FROM_STRATEGY: Record<
         ReadFrom,
         connection_request.ReadFrom
diff --git a/node/src/Commands.ts b/node/src/Commands.ts
index ffd24f4731..9b856cfdf3 100644
--- a/node/src/Commands.ts
+++ b/node/src/Commands.ts
@@ -863,3 +863,10 @@ export function createZpopmax(key: string, count?: number): redis_request.Comman
     const args: string[] = count == undefined ? [key] : [key, count.toString()];
     return createCommand(RequestType.ZPopMax, args);
 }
+
+/**
+ * @internal
+ */
+export function createEcho(message: string): redis_request.Command {
+    return createCommand(RequestType.Echo, [message]);
+}
diff --git a/node/src/Transaction.ts b/node/src/Transaction.ts
index cf6f3826b9..296f63c400 100644
--- a/node/src/Transaction.ts
+++ b/node/src/Transaction.ts
@@ -18,6 +18,7 @@ import {
     createDecr,
     createDecrBy,
     createDel,
+    createEcho,
     createExists,
     createExpire,
     createExpireAt,
@@ -900,6 +901,17 @@ export class BaseTransaction<T extends BaseTransaction<T>> {
         return this.addAndReturn(createZpopmax(key, count));
     }
 
+    /** Echoes the provided `message` back.
+     * See https://redis.io/commands/echo for more details.
+     * 
+     * @param message - The message to be echoed back.
+     * 
+     * Command Response - The provided `message`.
+     */
+    public echo(message: string): T {
+        return this.addAndReturn(createEcho(message));
+    }
+
     /** Executes a single command, without checking inputs. Every part of the command, including subcommands,
      *  should be added as a separate value in args.
      *
diff --git a/node/tests/SharedTests.ts b/node/tests/SharedTests.ts
index 2ed87bedbb..cb23636dbc 100644
--- a/node/tests/SharedTests.ts
+++ b/node/tests/SharedTests.ts
@@ -1532,6 +1532,17 @@ export function runBaseTests<Context>(config: {
         config.timeout
     );
 
+    it.each([ProtocolVersion.RESP2, ProtocolVersion.RESP3])(
+        `echo test_%p`,
+        async (protocol) => {
+            await runTest(async (client: BaseClient) => {
+                const message = uuidv4();
+                expect(await client.echo(message)).toEqual(message);
+            }, protocol);
+        },
+        config.timeout
+    );
+
     it.each([ProtocolVersion.RESP2, ProtocolVersion.RESP3])(
         `strlen test_%p`,
         async (protocol) => {
diff --git a/node/tests/TestUtilities.ts b/node/tests/TestUtilities.ts
index fadf6e5fde..553b3b3224 100644
--- a/node/tests/TestUtilities.ts
+++ b/node/tests/TestUtilities.ts
@@ -68,6 +68,8 @@ export function transactionTest(
     args.push("OK");
     baseTransaction.type(key1);
     args.push("string");
+    baseTransaction.echo(value);
+    args.push(value);
     baseTransaction.set(key2, "baz", {
         returnOldValue: true,
     });