Node: Added hlen command.

node/src/BaseClient.ts

@@ -28,6 +28,7 @@ import {
     createHGetAll,
     createHIncrBy,
     createHIncrByFloat,
+    createHLen,
     createHMGet,
     createHSet,
     createIncr,
@@ -616,6 +617,16 @@ export class BaseClient {
         return this.createWritePromise(createHIncrByFloat(key, field, amount));
     }
 
+    /** Returns the number of fields contained in the hash stored at `key`.
+     * See https://redis.io/commands/hlen/ for more details.
+     * 
+     * @param key - The key of the hash.
+     * @returns The number of fields in the hash, or 0 when the key does not exist.
+     */
+    public hlen(key: string): Promise<number> {
+        return this.createWritePromise(createHLen(key));
+    }
+
     /** Inserts all the specified values at the head of the list stored at `key`.
      * `elements` are inserted one after the other to the head of the list, from the leftmost element to the rightmost element.
      * If `key` does not exist, it is created as empty list before performing the push operations.

node/src/Commands.ts

@@ -585,6 +585,13 @@ export function createHIncrByFloat(
     ]);
 }
 
+/**
+ * @internal
+ */
+export function createHLen(key: string): redis_request.Command {
+    return createCommand(RequestType.HLen, [key]);
+}
+
 /**
  * @internal
  */

node/src/Transaction.ts

@@ -28,6 +28,7 @@ import {
     createHGetAll,
     createHIncrBy,
     createHIncrByFloat,
+    createHLen,
     createHMGet,
     createHSet,
     createIncr,
@@ -409,6 +410,17 @@ export class BaseTransaction<T extends BaseTransaction<T>> {
         return this.addAndReturn(createHIncrByFloat(key, field, amount));
     }
 
+    /** Returns the number of fields contained in the hash stored at `key`.
+     * See https://redis.io/commands/hlen/ for more details.
+     * 
+     * @param key - The key of the hash.
+     * 
+     * Command Response - The number of fields in the hash, or 0 when the key does not exist.
+     */
+    public hlen(key: string): T {
+        return this.addAndReturn(createHLen(key));
+    }
+
     /** Inserts all the specified values at the head of the list stored at `key`.
      * `elements` are inserted one after the other to the head of the list, from the leftmost element to the rightmost element.
      * If `key` does not exist, it is created as empty list before performing the push operations.

node/tests/SharedTests.ts

@@ -750,6 +750,28 @@ export function runBaseTests<Context>(config: {
         config.timeout
     );
 
+    it.each([ProtocolVersion.RESP2, ProtocolVersion.RESP3])(
+        `hlen test_%p`,
+        async (protocol) => {
+            await runTest(async (client: BaseClient) => {
+                const key1 = uuidv4();
+                const field1 = uuidv4();
+                const field2 = uuidv4();
+                const fieldValueMap = {
+                    [field1]: "value1",
+                    [field2]: "value2",
+                };
+
+                expect(await client.hset(key1, fieldValueMap)).toEqual(2);
+                expect(await client.hlen(key1)).toEqual(2);
+                expect(await client.hdel(key1, [field1])).toEqual(1);
+                expect(await client.hlen(key1)).toEqual(1);
+                expect(await client.hlen("nonExistingHash")).toEqual(0);
+            }, protocol);
+        },
+        config.timeout
+    );
+
     it.each([ProtocolVersion.RESP2, ProtocolVersion.RESP3])(
         `lpush, lpop and lrange with existing and non existing key_%p`,
         async (protocol) => {

node/tests/TestUtilities.ts

@@ -82,6 +82,8 @@ export function transactionTest(
     args.push(1);
     baseTransaction.hset(key4, { [field]: value });
     args.push(1);
+    baseTransaction.hlen(key4);
+    args.push(1);
     baseTransaction.hget(key4, field);
     args.push(value);
     baseTransaction.hgetall(key4);