Python: adds HLEN command (#944)

CHANGELOG.md

@@ -10,6 +10,7 @@
 * Standalone client: Improve connection errors. ([#854](https://github.com/aws/glide-for-redis/pull/854))
 * Python, Node: When recieving LPOP/RPOP with count, convert result to Array. ([#811](https://github.com/aws/glide-for-redis/pull/811))
 * Python: Added TYPE command ([#945](https://github.com/aws/glide-for-redis/pull/945))
+* Python: Added HLEN command ([#944](https://github.com/aws/glide-for-redis/pull/944))
 
 #### Features
 * Python, Node: Added support in Lua Scripts ([#775](https://github.com/aws/glide-for-redis/pull/775), [#860](https://github.com/aws/glide-for-redis/pull/860))

glide-core/src/protobuf/redis_request.proto

@@ -104,6 +104,7 @@ enum RequestType {
     ZIncrBy = 66;
     ZScore = 67;
     Type = 68;
+    HLen = 69;
 }
 
 message Command {

glide-core/src/socket_listener.rs

@@ -347,6 +347,7 @@ fn get_command(request: &Command) -> Option<Cmd> {
         RequestType::ZIncrBy => Some(cmd("ZINCRBY")),
         RequestType::ZScore => Some(cmd("ZSCORE")),
         RequestType::Type => Some(cmd("TYPE")),
+        RequestType::HLen => Some(cmd("HLEN")),
     }
 }
 

python/python/glide/async_commands/core.py

@@ -589,6 +589,27 @@ async def hdel(self, key: str, fields: List[str]) -> int:
             int, await self._execute_command(RequestType.HashDel, [key] + fields)
         )
 
+    async def hlen(self, key: str) -> int:
+        """
+        Returns the number of fields contained in the hash stored at `key`.
+
+        See https://redis.io/commands/hlen/ for more details.
+
+        Args:
+            key (str): The key of the hash.
+
+        Returns:
+            int: The number of fields in the hash, or 0 when the key does not exist.
+            If `key` holds a value that is not a hash, an error is returned.
+
+        Examples:
+            >>> await client.hlen("my_hash")
+                3
+            >>> await client.hlen("non_existing_key")
+                0
+        """
+        return cast(int, await self._execute_command(RequestType.HLen, [key]))
+
     async def lpush(self, key: str, elements: List[str]) -> int:
         """Insert 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

python/python/glide/async_commands/transaction.py

@@ -366,6 +366,21 @@ def hexists(self, key: str, field: str):
         """
         self.append_command(RequestType.HashExists, [key, field])
 
+    def hlen(self, key: str):
+        """
+        Returns the number of fields contained in the hash stored at `key`.
+
+        See https://redis.io/commands/hlen/ for more details.
+
+        Args:
+            key (str): The key of the hash.
+
+        Command response:
+            int: The number of fields in the hash, or 0 when the key does not exist.
+            If `key` holds a value that is not a hash, the transaction fails with an error.
+        """
+        self.append_command(RequestType.HLen, [key])
+
     def client_getname(self):
         """
         Get the name of the connection on which the transaction is being executed.

python/python/tests/test_async_client.py

@@ -718,6 +718,25 @@ async def test_hexist(self, redis_client: TRedisClient):
         assert await redis_client.hexists(key, "nonExistingField") == False
         assert await redis_client.hexists("nonExistingKey", field2) == False
 
+    @pytest.mark.parametrize("cluster_mode", [True, False])
+    @pytest.mark.parametrize("protocol", [ProtocolVersion.RESP2, ProtocolVersion.RESP3])
+    async def test_hlen(self, redis_client: TRedisClient):
+        key = get_random_string(10)
+        key2 = get_random_string(5)
+        field = get_random_string(5)
+        field2 = get_random_string(5)
+        field_value_map = {field: "value", field2: "value2"}
+
+        assert await redis_client.hset(key, field_value_map) == 2
+        assert await redis_client.hlen(key) == 2
+        assert await redis_client.hdel(key, [field]) == 1
+        assert await redis_client.hlen(key) == 1
+        assert await redis_client.hlen("non_existing_hash") == 0
+
+        assert await redis_client.set(key2, "value") == OK
+        with pytest.raises(RequestError):
+            await redis_client.hlen(key2)
+
     @pytest.mark.parametrize("cluster_mode", [True, False])
     @pytest.mark.parametrize("protocol", [ProtocolVersion.RESP2, ProtocolVersion.RESP3])
     async def test_lpush_lpop_lrange(self, redis_client: TRedisClient):

python/python/tests/test_transaction.py

@@ -62,6 +62,7 @@ def transaction_test(
 
     transaction.hset(key4, {key: value, key2: value2})
     transaction.hget(key4, key2)
+    transaction.hlen(key4)
 
     transaction.hincrby(key4, key3, 5)
     transaction.hincrbyfloat(key4, key3, 5.5)
@@ -116,6 +117,7 @@ def transaction_test(
         {"timeout": "1000"},
         2,
         value2,
+        2,
         5,
         10.5,
         True,