From 3a45d3291b117d376c901108cb061440fd2ad964 Mon Sep 17 00:00:00 2001
From: Adam Hopkins <admhpkns@gmail.com>
Date: Mon, 22 Feb 2021 13:39:16 +0200
Subject: [PATCH] Add support for 3.7 checking of mock transport

---
 sanic/models/asgi.py      | 95 +++++++++++++++++++++++++++++++++++++++
 sanic/models/transport.py | 21 +++++++++
 2 files changed, 116 insertions(+)
 create mode 100644 sanic/models/asgi.py
 create mode 100644 sanic/models/transport.py

diff --git a/sanic/models/asgi.py b/sanic/models/asgi.py
new file mode 100644
index 00000000..595b0553
--- /dev/null
+++ b/sanic/models/asgi.py
@@ -0,0 +1,95 @@
+import asyncio
+
+from typing import Any, Awaitable, Callable, MutableMapping, Optional, Union
+
+from sanic.exceptions import InvalidUsage
+from sanic.websocket import WebSocketConnection
+
+
+ASGIScope = MutableMapping[str, Any]
+ASGIMessage = MutableMapping[str, Any]
+ASGISend = Callable[[ASGIMessage], Awaitable[None]]
+ASGIReceive = Callable[[], Awaitable[ASGIMessage]]
+
+
+class MockProtocol:
+    def __init__(self, transport: "MockTransport", loop):
+        self.transport = transport
+        self._not_paused = asyncio.Event(loop=loop)
+        self._not_paused.set()
+        self._complete = asyncio.Event(loop=loop)
+
+    def pause_writing(self) -> None:
+        self._not_paused.clear()
+
+    def resume_writing(self) -> None:
+        self._not_paused.set()
+
+    async def complete(self) -> None:
+        self._not_paused.set()
+        await self.transport.send(
+            {"type": "http.response.body", "body": b"", "more_body": False}
+        )
+
+    @property
+    def is_complete(self) -> bool:
+        return self._complete.is_set()
+
+    async def push_data(self, data: bytes) -> None:
+        if not self.is_complete:
+            await self.transport.send(
+                {"type": "http.response.body", "body": data, "more_body": True}
+            )
+
+    async def drain(self) -> None:
+        await self._not_paused.wait()
+
+
+class MockTransport:
+    _protocol: Optional[MockProtocol]
+
+    def __init__(
+        self, scope: ASGIScope, receive: ASGIReceive, send: ASGISend
+    ) -> None:
+        self.scope = scope
+        self._receive = receive
+        self._send = send
+        self._protocol = None
+        self.loop = None
+
+    def get_protocol(self) -> MockProtocol:
+        if not self._protocol:
+            self._protocol = MockProtocol(self, self.loop)
+        return self._protocol
+
+    def get_extra_info(self, info: str) -> Union[str, bool, None]:
+        if info == "peername":
+            return self.scope.get("client")
+        elif info == "sslcontext":
+            return self.scope.get("scheme") in ["https", "wss"]
+        return None
+
+    def get_websocket_connection(self) -> WebSocketConnection:
+        try:
+            return self._websocket_connection
+        except AttributeError:
+            raise InvalidUsage("Improper websocket connection.")
+
+    def create_websocket_connection(
+        self, send: ASGISend, receive: ASGIReceive
+    ) -> WebSocketConnection:
+        self._websocket_connection = WebSocketConnection(
+            send, receive, self.scope.get("subprotocols", [])
+        )
+        return self._websocket_connection
+
+    def add_task(self) -> None:
+        raise NotImplementedError
+
+    async def send(self, data) -> None:
+        # TODO:
+        # - Validation on data and that it is formatted properly and is valid
+        await self._send(data)
+
+    async def receive(self) -> ASGIMessage:
+        return await self._receive()
diff --git a/sanic/models/transport.py b/sanic/models/transport.py
new file mode 100644
index 00000000..fc612dd6
--- /dev/null
+++ b/sanic/models/transport.py
@@ -0,0 +1,21 @@
+import sys
+
+from typing import Union
+
+
+if sys.version_info < (3, 8):
+    from asyncio import BaseTransport
+
+    from sanic.models.asgi import MockTransport
+
+    TransportProtocol = Union[MockTransport, BaseTransport]
+else:
+    # Protocol is a 3.8+ feature
+    from typing import Protocol
+
+    class TransportProtocol(Protocol):
+        def get_protocol(self):
+            ...
+
+        def get_extra_info(self, info: str) -> Union[str, bool, None]:
+            ...