protocol: support grpc-web

conformance/client_config.yaml

@@ -5,6 +5,7 @@ features:
   protocols:
     - PROTOCOL_CONNECT
     - PROTOCOL_GRPC
+    - PROTOCOL_GRPC_WEB
   codecs:
     - CODEC_PROTO
   compressions:
@@ -15,7 +16,6 @@ features:
     - STREAM_TYPE_CLIENT_STREAM
     - STREAM_TYPE_SERVER_STREAM
     - STREAM_TYPE_HALF_DUPLEX_BIDI_STREAM
-    # - STREAM_TYPE_FULL_DUPLEX_BIDI_STREAM
 
   supports_h2c: true
   supports_tls: true

conformance/server_config.yaml

@@ -5,6 +5,7 @@ features:
   protocols:
     - PROTOCOL_CONNECT
     - PROTOCOL_GRPC
+    - PROTOCOL_GRPC_WEB
   codecs:
     - CODEC_PROTO
     - CODEC_JSON

src/connect/envelope.py

@@ -23,6 +23,7 @@ class EnvelopeFlags(Flag):
 
     compressed = 0b00000001
     end_stream = 0b00000010
+    trailer = 0b10000000
 
 
 class Envelope:
@@ -253,7 +254,7 @@ class EnvelopeReader:
     stream: AsyncIterable[bytes] | None
     buffer: bytes
     bytes_read: int
-    last_data: bytes | None
+    last: Envelope | None
 
     def __init__(
         self,
@@ -277,7 +278,7 @@ def __init__(
         self.stream = stream
         self.buffer = b""
         self.bytes_read = 0
-        self.last_data = None
+        self.last = None
 
     async def unmarshal(self, message: Any) -> AsyncIterator[tuple[Any, bool]]:
         """Asynchronously unmarshals messages from the stream.
@@ -325,7 +326,7 @@ async def unmarshal(self, message: Any) -> AsyncIterator[tuple[Any, bool]]:
                     env.data = self.compression.decompress(env.data, self.read_max_bytes)
 
                 if env.flags != EnvelopeFlags(0) and env.flags != EnvelopeFlags.compressed:
-                    self.last_data = env.data
+                    self.last = env
                     end = True
                     obj = None
                 else:

src/connect/handler.py

@@ -123,7 +123,7 @@ def create_protocol_handlers(config: HandlerConfig) -> list[ProtocolHandler]:
         list[ProtocolHandler]: A list of initialized protocol handlers.
 
     """
-    protocols = [ProtocolConnect(), ProtocolGRPC(web=False)]
+    protocols = [ProtocolConnect(), ProtocolGRPC(web=False), ProtocolGRPC(web=True)]
 
     codecs = CodecMap(config.codecs)
 

src/connect/protocol_connect.py

@@ -1189,8 +1189,8 @@ async def unmarshal(self, message: Any) -> AsyncIterator[tuple[Any, bool]]:
 
         """
         async for obj, end in super().unmarshal(message):
-            if self.last_data:
-                error, trailers = end_stream_from_bytes(self.last_data)
+            if self.last:
+                error, trailers = end_stream_from_bytes(self.last.data)
                 self._end_stream_error = error
                 self._trailers = trailers