Add Quart adapter (resolving #619)

slack_bolt/adapter/quart/__init__.py

@@ -0,0 +1 @@
+from .async_handler import AsyncSlackRequestHandler

slack_bolt/adapter/quart/async_handler.py

@@ -0,0 +1,48 @@
+from quart import Request, Response, make_response
+
+from slack_bolt import BoltResponse
+from slack_bolt.async_app import AsyncApp, AsyncBoltRequest
+from slack_bolt.oauth.async_oauth_flow import AsyncOAuthFlow
+
+async def to_async_bolt_request(req: Request) -> AsyncBoltRequest:
+    body = await req.get_data(as_text=True)
+    return AsyncBoltRequest(
+        body=body,
+        query=req.query_string.decode("utf-8"),
+        headers=req.headers,
+    )
+
+async def to_quart_response(bolt_resp: BoltResponse) -> Response:
+    resp = await make_response(bolt_resp.body, bolt_resp.status)
+    for k, values in bolt_resp.headers.items():
+        if k.lower() == "content-type" and resp.headers.get("content-type") is not None:
+            # Remove the one set by Flask
+            resp.headers.pop("content-type")
+        for v in values:
+            resp.headers.add_header(k, v)
+    return resp
+
+class AsyncSlackRequestHandler:
+    def __init__(self, app: AsyncApp):  # type: ignore
+        self.app = app
+
+    async def handle(self, req: Request) -> Response:
+        if req.method == "GET":
+            if self.app.oauth_flow is not None:
+                oauth_flow: AsyncOAuthFlow = self.app.oauth_flow
+                if req.path == oauth_flow.install_path:
+                    bolt_resp = await oauth_flow.handle_installation(
+                        await to_async_bolt_request(req)
+                    )
+                    return await to_quart_response(bolt_resp)
+                elif req.path == oauth_flow.redirect_uri_path:
+                    bolt_resp = await oauth_flow.handle_callback(
+                        await to_async_bolt_request(req)
+                    )
+                    return await to_quart_response(bolt_resp)
+
+        elif req.method == "POST":
+            bolt_resp = await self.app.async_dispatch(await to_async_bolt_request(req))
+            return await to_quart_response(bolt_resp)
+
+        return await make_response("Not Found", 404)