Python: add LINSERT command (#227) (#1304)

* Python: add LINSERT command (#227)

* Minor update to test for clarification

* Fix linter

* PR suggestions

CHANGELOG.md

@@ -12,6 +12,7 @@
 * Python: Added GEOHASH command ([#1281](https://github.com/aws/glide-for-redis/pull/1281))
 * Python: Added ZLEXCOUNT command ([#1305](https://github.com/aws/glide-for-redis/pull/1305))
 * Python: Added ZREMRANGEBYLEX command ([#1306](https://github.com/aws/glide-for-redis/pull/1306))
+* Python: Added LINSERT command ([#1304](https://github.com/aws/glide-for-redis/pull/1304))
 
 #### Fixes
 * Python: Fix typing error "‘type’ object is not subscriptable" ([#1203](https://github.com/aws/glide-for-redis/pull/1203))

python/python/glide/async_commands/core.py

@@ -202,6 +202,11 @@ def get_cmd_args(self) -> List[str]:
         return [self.cmd_arg] if self.value is None else [self.cmd_arg, self.value]
 
 
+class InsertPosition(Enum):
+    BEFORE = "BEFORE"
+    AFTER = "AFTER"
+
+
 class CoreCommands(Protocol):
     async def _execute_command(
         self,
@@ -1060,6 +1065,37 @@ async def rpop_count(self, key: str, count: int) -> Optional[List[str]]:
             await self._execute_command(RequestType.RPop, [key, str(count)]),
         )
 
+    async def linsert(
+        self, key: str, position: InsertPosition, pivot: str, element: str
+    ) -> int:
+        """
+        Inserts `element` in the list at `key` either before or after the `pivot`.
+
+        See https://redis.io/commands/linsert/ for details.
+
+        Args:
+            key (str): The key of the list.
+            position (InsertPosition): The relative position to insert into - either `InsertPosition.BEFORE` or
+                `InsertPosition.AFTER` the `pivot`.
+            pivot (str): An element of the list.
+            element (str): The new element to insert.
+
+        Returns:
+            int: The list length after a successful insert operation.
+                If the `key` doesn't exist returns `-1`.
+                If the `pivot` wasn't found, returns `0`.
+
+        Examples:
+            >>> await client.linsert("my_list", InsertPosition.BEFORE, "World", "There")
+                3 # "There" was inserted before "World", and the new length of the list is 3.
+        """
+        return cast(
+            int,
+            await self._execute_command(
+                RequestType.LInsert, [key, position.value, pivot, element]
+            ),
+        )
+
     async def sadd(self, key: str, members: List[str]) -> int:
         """
         Add specified members to the set stored at `key`.

python/python/glide/async_commands/transaction.py

@@ -9,6 +9,7 @@
     ExpirySet,
     GeospatialData,
     InfoSection,
+    InsertPosition,
     UpdateOptions,
 )
 from glide.async_commands.sorted_set import (
@@ -773,6 +774,30 @@ def rpop_count(self: TTransaction, key: str, count: int) -> TTransaction:
         """
         return self.append_command(RequestType.RPop, [key, str(count)])
 
+    def linsert(
+        self: TTransaction, key: str, position: InsertPosition, pivot: str, element: str
+    ) -> TTransaction:
+        """
+        Inserts `element` in the list at `key` either before or after the `pivot`.
+
+        See https://redis.io/commands/linsert/ for details.
+
+        Args:
+            key (str): The key of the list.
+            position (InsertPosition): The relative position to insert into - either `InsertPosition.BEFORE` or
+                `InsertPosition.AFTER` the `pivot`.
+            pivot (str): An element of the list.
+            element (str): The new element to insert.
+
+        Command response:
+            int: The list length after a successful insert operation.
+                If the `key` doesn't exist returns `-1`.
+                If the `pivot` wasn't found, returns `0`.
+        """
+        return self.append_command(
+            RequestType.LInsert, [key, position.value, pivot, element]
+        )
+
     def sadd(self: TTransaction, key: str, members: List[str]) -> TTransaction:
         """
         Add specified members to the set stored at `key`.

python/python/tests/test_async_client.py

@@ -19,6 +19,7 @@
     GeospatialData,
     InfBound,
     InfoSection,
+    InsertPosition,
     UpdateOptions,
 )
 from glide.async_commands.sorted_set import (
@@ -908,6 +909,37 @@ async def test_rpushx(self, redis_client: TRedisClient):
         with pytest.raises(RequestError):
             await redis_client.rpushx(key2, [])
 
+    @pytest.mark.parametrize("cluster_mode", [True, False])
+    @pytest.mark.parametrize("protocol", [ProtocolVersion.RESP2, ProtocolVersion.RESP3])
+    async def test_linsert(self, redis_client: TRedisClient):
+        key1 = get_random_string(10)
+        key2 = get_random_string(10)
+
+        assert await redis_client.lpush(key1, ["4", "3", "2", "1"]) == 4
+        assert await redis_client.linsert(key1, InsertPosition.BEFORE, "2", "1.5") == 5
+        assert await redis_client.linsert(key1, InsertPosition.AFTER, "3", "3.5") == 6
+        assert await redis_client.lrange(key1, 0, -1) == [
+            "1",
+            "1.5",
+            "2",
+            "3",
+            "3.5",
+            "4",
+        ]
+
+        assert (
+            await redis_client.linsert(
+                "non_existing_key", InsertPosition.BEFORE, "pivot", "elem"
+            )
+            == 0
+        )
+        assert await redis_client.linsert(key1, InsertPosition.AFTER, "5", "6") == -1
+
+        # key exists, but it is not a list
+        assert await redis_client.set(key2, "value") == OK
+        with pytest.raises(RequestError):
+            await redis_client.linsert(key2, InsertPosition.AFTER, "p", "e")
+
     @pytest.mark.parametrize("cluster_mode", [True, False])
     @pytest.mark.parametrize("protocol", [ProtocolVersion.RESP2, ProtocolVersion.RESP3])
     async def test_sadd_srem_smembers_scard(self, redis_client: TRedisClient):

python/python/tests/test_transaction.py

@@ -5,7 +5,7 @@
 
 import pytest
 from glide import RequestError
-from glide.async_commands.core import GeospatialData
+from glide.async_commands.core import GeospatialData, InsertPosition
 from glide.async_commands.sorted_set import (
     InfBound,
     LexBoundary,
@@ -38,6 +38,7 @@ async def transaction_test(
     key7 = "{{{}}}:{}".format(keyslot, get_random_string(3))
     key8 = "{{{}}}:{}".format(keyslot, get_random_string(3))
     key9 = "{{{}}}:{}".format(keyslot, get_random_string(3))
+    key10 = "{{{}}}:{}".format(keyslot, get_random_string(3))  # list
 
     value = datetime.now(timezone.utc).strftime("%m/%d/%Y, %H:%M:%S")
     value2 = get_random_string(5)
@@ -147,6 +148,8 @@ async def transaction_test(
     args.append([value2, value])
     transaction.lpop_count(key5, 2)
     args.append([value2, value])
+    transaction.linsert(key5, InsertPosition.BEFORE, "non_existing_pivot", "element")
+    args.append(0)
 
     transaction.rpush(key6, [value, value2, value2])
     args.append(3)