Implement room version capabilities in CS API (#866)

* Add wiring for querying the roomserver for the default room version

* Try to implement /capabilities for room versions

* Update copyright notices

* Update sytests, add /capabilities endpoint into CS API

* Update sytest-whitelist

* Add GetDefaultRoomVersion

* Fix cases where state package was shadowed

* Fix version formatting

* Update Dockerfile to Go 1.13.6

* oh yes types I remember

* And fix the default too

2 files changed, 57 insertions, 0 deletions

diff --git a/clientapi/routing/capabilities.go b/clientapi/routing/capabilities.go
new file mode 100644
index 00000000..c8743386
--- /dev/null
+++ b/clientapi/routing/capabilities.go
@@ -0,0 +1,51 @@
+// Copyright 2020 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package routing
+
+import (
+	"net/http"
+
+	"github.com/matrix-org/dendrite/clientapi/httputil"
+	roomserverAPI "github.com/matrix-org/dendrite/roomserver/api"
+
+	"github.com/matrix-org/util"
+)
+
+// SendMembership implements PUT /rooms/{roomID}/(join|kick|ban|unban|leave|invite)
+// by building a m.room.member event then sending it to the room server
+func GetCapabilities(
+	req *http.Request, queryAPI roomserverAPI.RoomserverQueryAPI,
+) util.JSONResponse {
+	roomVersionsQueryReq := roomserverAPI.QueryRoomVersionCapabilitiesRequest{}
+	var roomVersionsQueryRes roomserverAPI.QueryRoomVersionCapabilitiesResponse
+	if err := queryAPI.QueryRoomVersionCapabilities(
+		req.Context(),
+		&roomVersionsQueryReq,
+		&roomVersionsQueryRes,
+	); err != nil {
+		return httputil.LogThenError(req, err)
+	}
+
+	response := map[string]interface{}{
+		"capabilities": map[string]interface{}{
+			"m.room_versions": roomVersionsQueryRes,
+		},
+	}
+
+	return util.JSONResponse{
+		Code: http.StatusOK,
+		JSON: response,
+	}
+}
diff --git a/clientapi/routing/routing.go b/clientapi/routing/routing.go
index 5c98cd0d..bd326900 100644
--- a/clientapi/routing/routing.go
+++ b/clientapi/routing/routing.go
@@ -551,4 +551,10 @@ func Setup(
 			return DeleteTag(req, accountDB, device, vars["userId"], vars["roomId"], vars["tag"], syncProducer)
 		}),
 	).Methods(http.MethodDelete, http.MethodOptions)
+
+	r0mux.Handle("/capabilities",
+		common.MakeAuthAPI("capabilities", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
+			return GetCapabilities(req, queryAPI)
+		}),
+	).Methods(http.MethodGet)
 }