Fix for stream uploads that subclass SyncByteStream/AsyncByteStream (#2016)

Author: tomchristie

httpx/_content.py

@@ -50,7 +50,9 @@ def __iter__(self) -> Iterator[bytes]:
             raise StreamConsumed()
 
         self._is_stream_consumed = True
-        if hasattr(self._stream, "read"):
+        if hasattr(self._stream, "read") and not isinstance(
+            self._stream, SyncByteStream
+        ):
             # File-like interfaces should use 'read' directly.
             chunk = self._stream.read(self.CHUNK_SIZE)  # type: ignore
             while chunk:
@@ -75,7 +77,9 @@ async def __aiter__(self) -> AsyncIterator[bytes]:
             raise StreamConsumed()
 
         self._is_stream_consumed = True
-        if hasattr(self._stream, "aread"):
+        if hasattr(self._stream, "aread") and not isinstance(
+            self._stream, AsyncByteStream
+        ):
             # File-like interfaces should use 'aread' directly.
             chunk = await self._stream.aread(self.CHUNK_SIZE)  # type: ignore
             while chunk:

tests/test_api.py

@@ -28,6 +28,18 @@ def data():
     assert response.reason_phrase == "OK"
 
 
+def test_post_byte_stream(server):
+    class Data(httpx.SyncByteStream):
+        def __iter__(self):
+            yield b"Hello"
+            yield b", "
+            yield b"world!"
+
+    response = httpx.post(server.url, content=Data())
+    assert response.status_code == 200
+    assert response.reason_phrase == "OK"
+
+
 def test_options(server):
     response = httpx.options(server.url)
     assert response.status_code == 200