Add websocket.handler.before/after/exception signals.

tests/test_ws_handlers.py

@@ -54,3 +54,65 @@ def test_ws_handler_async_for(
     )
     assert ws_proxy.client_sent == ["test 1", "test 2", ""]
     assert ws_proxy.client_received == ["test 1", "test 2"]
+
+
+def signalapp(app):
+    @app.signal("websocket.handler.before")
+    async def ws_before(request: Request, websocket: Websocket):
+        app.ctx.seq.append("before")
+        print("before")
+        await websocket.send("before: " + await websocket.recv())
+        print("before2")
+
+    @app.signal("websocket.handler.after")
+    async def ws_after(request: Request, websocket: Websocket):
+        app.ctx.seq.append("after")
+        await websocket.send("after: " + await websocket.recv())
+        await websocket.recv()
+
+    @app.signal("websocket.handler.exception")
+    async def ws_exception(
+        request: Request, websocket: Websocket, exception: Exception
+    ):
+        app.ctx.seq.append("exception")
+        await websocket.send(f"exception: {exception}")
+        await websocket.recv()
+
+    @app.websocket("/ws")
+    async def ws_handler(request: Request, ws: Websocket):
+        app.ctx.seq.append("ws")
+
+    @app.websocket("/wserror")
+    async def ws_error(request: Request, ws: Websocket):
+        print("wserr")
+        app.ctx.seq.append("wserror")
+        raise Exception(await ws.recv())
+        print("wserr2")
+
+
+def test_ws_signals(
+    app: Sanic,
+    simple_ws_mimic_client: MimicClientType,
+):
+    signalapp(app)
+
+    app.ctx.seq = []
+    _, ws_proxy = app.test_client.websocket(
+        "/ws", mimic=simple_ws_mimic_client
+    )
+    assert ws_proxy.client_received == ["before: test 1", "after: test 2"]
+    assert app.ctx.seq == ["before", "ws", "after"]
+
+
+def test_ws_signals_exception(
+    app: Sanic,
+    simple_ws_mimic_client: MimicClientType,
+):
+    signalapp(app)
+
+    app.ctx.seq = []
+    _, ws_proxy = app.test_client.websocket(
+        "/wserror", mimic=simple_ws_mimic_client
+    )
+    assert ws_proxy.client_received == ["before: test 1", "exception: test 2"]
+    assert app.ctx.seq == ["before", "wserror", "exception"]