Handle MINID in xadd

aredis/commands/streams.py

@@ -50,7 +50,7 @@ class StreamsCommandMixin:
     )
 
     async def xadd(self, name: str, entry: dict,
-                   max_len=None, stream_id='*',
+                   max_len=None, min_id=None, stream_id="*",
                    approximate=True) -> str:
         """
         Appends the specified stream entry to the stream at the specified key.
@@ -62,9 +62,12 @@ async def xadd(self, name: str, entry: dict,
         :param name: name of the stream
         :param entry: key-values to be appended to the stream
         :param max_len: max length of the stream
-        length will not be limited max_len is set to None
-        notice: max_len should be int greater than 0,
-        if set to 0 or negative, the stream length will not be limited
+        length will not be limited if max_len is set to None
+        notice: max_len should be an int greater than 0,
+
+        :param min_id: minimum id of the stream
+        if set, evicts entries with IDs lower than the one specified
+        max_len & min_id are mutually exclusive
 
         :param stream_id: id of the options appended to the stream.
         The XADD command will auto-generate a unique id for you
@@ -80,17 +83,28 @@ async def xadd(self, name: str, entry: dict,
         notice: specified id without "-" character will be completed like "id-0"
         """
         pieces = []
+
+        if max_len is not None and min_id is not None:
+            raise RedisError("XADD max_len & min_id are mutually exclusive")
         if max_len is not None:
             if not isinstance(max_len, int) or max_len < 1:
                 raise RedisError("XADD maxlen must be a positive integer")
-            pieces.append('MAXLEN')
+            pieces.append("MAXLEN")
             if approximate:
-                pieces.append('~')
+                pieces.append("~")
             pieces.append(str(max_len))
+        if min_id is not None:
+            if not isinstance(min_id, str):
+                raise RedisError("XADD min_id must be a string")
+            pieces.append("MINID")
+            if approximate:
+                pieces.append("~")
+            pieces.append(min_id)
+
         pieces.append(stream_id)
         for kv in entry.items():
             pieces.extend(list(kv))
-        return await self.execute_command('XADD', name, *pieces)
+        return await self.execute_command("XADD", name, *pieces)
 
     async def xlen(self, name: str) -> int:
         """