update tests, add repro of issue. reorder client.rpc_metadata setter

Author: jazev-stripe

temporalio/client.py

@@ -312,8 +312,9 @@ def rpc_metadata(self, value: Mapping[str, str | bytes]) -> None:
         mapping if changes are needed.
         """
         # Update config and perform update
-        self.service_client.config.rpc_metadata = value
+        # This may raise if the metadata is invalid:
         self.service_client.update_rpc_metadata(value)
+        self.service_client.config.rpc_metadata = value
 
     @property
     def api_key(self) -> Optional[str]:

tests/api/test_grpc_stub.py

@@ -1,5 +1,7 @@
 from datetime import timedelta
-from typing import Mapping
+from typing import Mapping, Any, cast
+import pytest
+import re
 
 from google.protobuf.empty_pb2 import Empty
 from google.protobuf.timestamp_pb2 import Timestamp
@@ -153,7 +155,7 @@ async def test_grpc_metadata():
     # Binary metadata should be configurable on the client:
     client.rpc_metadata = {
         "my-binary-key-bin": b"\x00\x01",
-        "my-binary-key-bin2": b"\x02\x03",
+        "my-binary-key2-bin": b"\x02\x03",
     }
     await client.workflow_service.get_system_info(
         GetSystemInfoRequest(),
@@ -165,7 +167,100 @@ async def test_grpc_metadata():
         {
             "authorization": "Bearer my-api-key",
             "my-binary-key-bin": b"abc",
-            "my-binary-key-bin2": b"\x02\x03",
+            "my-binary-key2-bin": b"\x02\x03",
+        }
+    )
+
+    # Setting invalid RPC metadata should raise:
+    with pytest.raises(
+        ValueError,
+        match="Invalid binary header key 'my-ascii-key': invalid gRPC metadata key name",
+    ):
+        client.rpc_metadata = {
+            "my-ascii-key": b"binary-value",
+        }
+    with pytest.raises(
+        ValueError,
+        match="Invalid ASCII header key 'my-binary-key-bin': invalid gRPC metadata key name",
+    ):
+        client.rpc_metadata = {
+            "my-binary-key-bin": "ascii-value",
+        }
+
+    # Making a request with invalid RPC metadata should raise:
+    with pytest.raises(
+        ValueError,
+        match="Invalid metadata value for ASCII key my-ascii-key: expected str",
+    ):
+        await client.workflow_service.get_system_info(
+            GetSystemInfoRequest(),
+            metadata={
+                "my-ascii-key": b"binary-value",
+            },
+        )
+    with pytest.raises(
+        ValueError,
+        match="Invalid metadata value for binary key my-binary-key-bin: expected bytes",
+    ):
+        await client.workflow_service.get_system_info(
+            GetSystemInfoRequest(),
+            metadata={
+                "my-binary-key-bin": "ascii-value",
+            },
+        )
+
+    # Passing in non-`str | bytes` should raise:
+    with pytest.raises(TypeError) as err:
+        await client.workflow_service.get_system_info(
+            GetSystemInfoRequest(),
+            metadata={
+                # Not a valid header:
+                "my-int-key": cast(Any, 256),
+            },
+        )
+    cause = err.value.__cause__
+    assert isinstance(cause, TypeError)
+    assert re.match(
+        re.escape(r"failed to extract enum RpcMetadataValue ('str | bytes')"),
+        str(cause),
+    )
+    with pytest.raises(
+        TypeError,
+        match=re.escape(r"failed to extract enum RpcMetadataValue ('str | bytes')"),
+    ) as err:
+        client.rpc_metadata = {
+            "my-binary-key-bin": cast(Any, 256),
+        }
+
+    # Setting invalid RPC metadata in a mixed client will partially fail:
+    client.rpc_metadata = {
+        "x-my-binary-bin": b"\x00",
+        "x-my-ascii": "foo",
+    }
+    assert client.rpc_metadata == {
+        "x-my-binary-bin": b"\x00",
+        "x-my-ascii": "foo",
+    }
+    with pytest.raises(
+        ValueError,
+        match="Invalid binary header key 'x-invalid-ascii-with-bin-value': invalid gRPC metadata key name",
+    ):
+        client.rpc_metadata = {
+            "x-invalid-ascii-with-bin-value": b"not-ascii",
+            "x-my-ascii": "bar",
+        }
+    assert client.rpc_metadata == {
+        "x-my-binary-bin": b"\x00",
+        "x-my-ascii": "foo",
+    }
+    await client.workflow_service.get_system_info(GetSystemInfoRequest())
+    workflow_server.assert_last_metadata(
+        {
+            "authorization": "Bearer my-api-key",
+            # This is inconsistent with what `client.rpc_metadata` returns
+            # (`x-my-ascii` was updated):
+            "x-my-binary-bin": b"\x00",
+            "x-my-ascii": "bar",
         }
     )