Change to using switch on err types with nonexistent rooms

clientapi/routing/admin.go

@@ -31,7 +31,7 @@ func AdminEvacuateRoom(req *http.Request, rsAPI roomserverAPI.ClientRoomserverAP
 	}
 
 	affected, err := rsAPI.PerformAdminEvacuateRoom(req.Context(), vars["roomID"])
-	switch err {
+	switch err.(type) {
 	case nil:
 	case eventutil.ErrRoomNoExists:
 		return util.JSONResponse{
@@ -231,10 +231,10 @@ func AdminDownloadState(req *http.Request, device *api.Device, rsAPI roomserverA
 		}
 	}
 	if err = rsAPI.PerformAdminDownloadState(req.Context(), roomID, device.UserID, spec.ServerName(serverName)); err != nil {
-		if errors.Is(err, eventutil.ErrRoomNoExists) {
+		if errors.Is(err, eventutil.ErrRoomNoExists{}) {
 			return util.JSONResponse{
 				Code: 200,
-				JSON: spec.NotFound(eventutil.ErrRoomNoExists.Error()),
+				JSON: spec.NotFound(err.Error()),
 			}
 		}
 		logrus.WithError(err).WithFields(logrus.Fields{

clientapi/routing/joinroom.go

@@ -16,7 +16,6 @@ package routing
 
 import (
 	"encoding/json"
-	"errors"
 	"net/http"
 	"time"
 
@@ -114,17 +113,16 @@ func JoinRoomByIDOrAlias(
 				Code: e.Code,
 				JSON: json.RawMessage(e.Message),
 			}
+		case eventutil.ErrRoomNoExists:
+			response = util.JSONResponse{
+				Code: http.StatusNotFound,
+				JSON: spec.NotFound(e.Error()),
+			}
 		default:
 			response = util.JSONResponse{
 				Code: http.StatusInternalServerError,
 				JSON: spec.InternalServerError(),
 			}
-			if errors.Is(err, eventutil.ErrRoomNoExists) {
-				response = util.JSONResponse{
-					Code: http.StatusNotFound,
-					JSON: spec.NotFound(e.Error()),
-				}
-			}
 		}
 		done <- response
 	}()

clientapi/routing/membership.go

@@ -398,28 +398,33 @@ func checkAndProcessThreepid(
 		req.Context(), device, body, cfg, rsAPI, profileAPI,
 		roomID, evTime,
 	)
-	if err == threepid.ErrMissingParameter {
+	switch e := err.(type) {
+	case nil:
+	case threepid.ErrMissingParameter:
+		util.GetLogger(req.Context()).WithError(err).Error("threepid.CheckAndProcessInvite failed")
 		return inviteStored, &util.JSONResponse{
 			Code: http.StatusBadRequest,
 			JSON: spec.BadJSON(err.Error()),
 		}
-	} else if err == threepid.ErrNotTrusted {
+	case threepid.ErrNotTrusted:
+		util.GetLogger(req.Context()).WithError(err).Error("threepid.CheckAndProcessInvite failed")
 		return inviteStored, &util.JSONResponse{
 			Code: http.StatusBadRequest,
 			JSON: spec.NotTrusted(body.IDServer),
 		}
-	} else if err == eventutil.ErrRoomNoExists {
+	case eventutil.ErrRoomNoExists:
+		util.GetLogger(req.Context()).WithError(err).Error("threepid.CheckAndProcessInvite failed")
 		return inviteStored, &util.JSONResponse{
 			Code: http.StatusNotFound,
 			JSON: spec.NotFound(err.Error()),
 		}
-	} else if e, ok := err.(gomatrixserverlib.BadJSONError); ok {
+	case gomatrixserverlib.BadJSONError:
+		util.GetLogger(req.Context()).WithError(err).Error("threepid.CheckAndProcessInvite failed")
 		return inviteStored, &util.JSONResponse{
 			Code: http.StatusBadRequest,
 			JSON: spec.BadJSON(e.Error()),
 		}
-	}
+	default:
-	if err != nil {
 		util.GetLogger(req.Context()).WithError(err).Error("threepid.CheckAndProcessInvite failed")
 		er := spec.InternalServerError()
 		return inviteStored, &er

clientapi/routing/redaction.go

@@ -16,6 +16,7 @@ package routing
 
 import (
 	"context"
+	"errors"
 	"net/http"
 	"time"
 
@@ -131,7 +132,7 @@ func SendRedaction(
 
 	var queryRes roomserverAPI.QueryLatestEventsAndStateResponse
 	e, err := eventutil.QueryAndBuildEvent(req.Context(), &proto, cfg.Matrix, identity, time.Now(), rsAPI, &queryRes)
-	if err == eventutil.ErrRoomNoExists {
+	if errors.Is(err, eventutil.ErrRoomNoExists{}) {
 		return util.JSONResponse{
 			Code: http.StatusNotFound,
 			JSON: spec.NotFound("Room does not exist"),

clientapi/routing/sendevent.go

@@ -284,28 +284,30 @@ func generateSendEvent(
 
 	var queryRes api.QueryLatestEventsAndStateResponse
 	e, err := eventutil.QueryAndBuildEvent(ctx, &proto, cfg.Matrix, identity, evTime, rsAPI, &queryRes)
-	if err == eventutil.ErrRoomNoExists {
+	switch specificErr := err.(type) {
+	case nil:
+	case eventutil.ErrRoomNoExists:
 		return nil, &util.JSONResponse{
 			Code: http.StatusNotFound,
 			JSON: spec.NotFound("Room does not exist"),
 		}
-	} else if e, ok := err.(gomatrixserverlib.BadJSONError); ok {
+	case gomatrixserverlib.BadJSONError:
 		return nil, &util.JSONResponse{
 			Code: http.StatusBadRequest,
-			JSON: spec.BadJSON(e.Error()),
+			JSON: spec.BadJSON(specificErr.Error()),
 		}
-	} else if e, ok := err.(gomatrixserverlib.EventValidationError); ok {
+	case gomatrixserverlib.EventValidationError:
-		if e.Code == gomatrixserverlib.EventValidationTooLarge {
+		if specificErr.Code == gomatrixserverlib.EventValidationTooLarge {
 			return nil, &util.JSONResponse{
 				Code: http.StatusRequestEntityTooLarge,
-				JSON: spec.BadJSON(e.Error()),
+				JSON: spec.BadJSON(specificErr.Error()),
 			}
 		}
 		return nil, &util.JSONResponse{
 			Code: http.StatusBadRequest,
-			JSON: spec.BadJSON(e.Error()),
+			JSON: spec.BadJSON(specificErr.Error()),
 		}
-	} else if err != nil {
+	default:
 		util.GetLogger(ctx).WithError(err).Error("eventutil.BuildEvent failed")
 		resErr := spec.InternalServerError()
 		return nil, &resErr

clientapi/routing/threepid.go

@@ -74,12 +74,15 @@ func RequestEmailToken(req *http.Request, threePIDAPI api.ClientUserAPI, cfg *co
 	}
 
 	resp.SID, err = threepid.CreateSession(req.Context(), body, cfg, client)
-	if err == threepid.ErrNotTrusted {
+	switch err.(type) {
+	case nil:
+	case threepid.ErrNotTrusted:
+		util.GetLogger(req.Context()).WithError(err).Error("threepid.CreateSession failed")
 		return util.JSONResponse{
 			Code: http.StatusBadRequest,
 			JSON: spec.NotTrusted(body.IDServer),
 		}
-	} else if err != nil {
+	default:
 		util.GetLogger(req.Context()).WithError(err).Error("threepid.CreateSession failed")
 		return spec.InternalServerError()
 	}
@@ -102,12 +105,15 @@ func CheckAndSave3PIDAssociation(
 
 	// Check if the association has been validated
 	verified, address, medium, err := threepid.CheckAssociation(req.Context(), body.Creds, cfg, client)
-	if err == threepid.ErrNotTrusted {
+	switch err.(type) {
+	case nil:
+	case threepid.ErrNotTrusted:
+		util.GetLogger(req.Context()).WithError(err).Error("threepid.CheckAssociation failed")
 		return util.JSONResponse{
 			Code: http.StatusBadRequest,
 			JSON: spec.NotTrusted(body.Creds.IDServer),
 		}
-	} else if err != nil {
+	default:
 		util.GetLogger(req.Context()).WithError(err).Error("threepid.CheckAssociation failed")
 		return spec.InternalServerError()
 	}

clientapi/routing/upgrade_room.go

@@ -68,7 +68,7 @@ func UpgradeRoom(
 			JSON: spec.Forbidden(e.Error()),
 		}
 	default:
-		if errors.Is(err, eventutil.ErrRoomNoExists) {
+		if errors.Is(err, eventutil.ErrRoomNoExists{}) {
 			return util.JSONResponse{
 				Code: http.StatusNotFound,
 				JSON: spec.NotFound("Room does not exist"),

clientapi/threepid/invites.go

@@ -64,14 +64,34 @@ type idServerStoreInviteResponse struct {
 }
 
 var (
-	// ErrMissingParameter is the error raised if a request for 3PID invite has
+	errMissingParameter = fmt.Errorf("'address', 'id_server' and 'medium' must all be supplied")
-	// an incomplete body
+	errNotTrusted       = fmt.Errorf("untrusted server")
-	ErrMissingParameter = errors.New("'address', 'id_server' and 'medium' must all be supplied")
-	// ErrNotTrusted is the error raised if an identity server isn't in the list
-	// of trusted servers in the configuration file.
-	ErrNotTrusted = errors.New("untrusted server")
 )
 
+// ErrMissingParameter is the error raised if a request for 3PID invite has
+// an incomplete body
+type ErrMissingParameter struct{}
+
+func (e ErrMissingParameter) Error() string {
+	return errMissingParameter.Error()
+}
+
+func (e ErrMissingParameter) Unwrap() error {
+	return errMissingParameter
+}
+
+// ErrNotTrusted is the error raised if an identity server isn't in the list
+// of trusted servers in the configuration file.
+type ErrNotTrusted struct{}
+
+func (e ErrNotTrusted) Error() string {
+	return errNotTrusted.Error()
+}
+
+func (e ErrNotTrusted) Unwrap() error {
+	return errNotTrusted
+}
+
 // CheckAndProcessInvite analyses the body of an incoming membership request.
 // If the fields relative to a third-party-invite are all supplied, lookups the
 // matching Matrix ID from the given identity server. If no Matrix ID is
@@ -99,7 +119,7 @@ func CheckAndProcessInvite(
 	} else if body.Address == "" || body.IDServer == "" || body.Medium == "" {
 		// If at least one of the 3PID-specific fields is supplied but not all
 		// of them, return an error
-		err = ErrMissingParameter
+		err = ErrMissingParameter{}
 		return
 	}
 

clientapi/threepid/threepid.go

@@ -186,5 +186,5 @@ func isTrusted(idServer string, cfg *config.ClientAPI) error {
 			return nil
 		}
 	}
-	return ErrNotTrusted
+	return ErrNotTrusted{}
 }

federationapi/routing/join.go

@@ -119,20 +119,24 @@ func MakeJoin(
 			RoomVersion: roomVersion,
 		}
 		event, err := eventutil.QueryAndBuildEvent(httpReq.Context(), proto, cfg.Matrix, identity, time.Now(), rsAPI, &queryRes)
-		if err == eventutil.ErrRoomNoExists {
+		switch e := err.(type) {
+		case nil:
+		case eventutil.ErrRoomNoExists:
+			util.GetLogger(httpReq.Context()).WithError(err).Error("eventutil.BuildEvent failed")
 			return nil, nil, &util.JSONResponse{
 				Code: http.StatusNotFound,
 				JSON: spec.NotFound("Room does not exist"),
 			}
-		} else if e, ok := err.(gomatrixserverlib.BadJSONError); ok {
+		case gomatrixserverlib.BadJSONError:
+			util.GetLogger(httpReq.Context()).WithError(err).Error("eventutil.BuildEvent failed")
 			return nil, nil, &util.JSONResponse{
 				Code: http.StatusBadRequest,
 				JSON: spec.BadJSON(e.Error()),
 			}
-		} else if err != nil {
+		default:
 			util.GetLogger(httpReq.Context()).WithError(err).Error("eventutil.BuildEvent failed")
-			e := spec.InternalServerError()
+			internalErr := spec.InternalServerError()
-			return nil, nil, &e
+			return nil, nil, &internalErr
 		}
 
 		stateEvents := make([]gomatrixserverlib.PDU, len(queryRes.StateEvents))

federationapi/routing/leave.go

@@ -75,17 +75,21 @@ func MakeLeave(
 
 	var queryRes api.QueryLatestEventsAndStateResponse
 	event, err := eventutil.QueryAndBuildEvent(httpReq.Context(), &proto, cfg.Matrix, identity, time.Now(), rsAPI, &queryRes)
-	if err == eventutil.ErrRoomNoExists {
+	switch e := err.(type) {
+	case nil:
+	case eventutil.ErrRoomNoExists:
+		util.GetLogger(httpReq.Context()).WithError(err).Error("eventutil.BuildEvent failed")
 		return util.JSONResponse{
 			Code: http.StatusNotFound,
 			JSON: spec.NotFound("Room does not exist"),
 		}
-	} else if e, ok := err.(gomatrixserverlib.BadJSONError); ok {
+	case gomatrixserverlib.BadJSONError:
+		util.GetLogger(httpReq.Context()).WithError(err).Error("eventutil.BuildEvent failed")
 		return util.JSONResponse{
 			Code: http.StatusBadRequest,
 			JSON: spec.BadJSON(e.Error()),
 		}
-	} else if err != nil {
+	default:
 		util.GetLogger(httpReq.Context()).WithError(err).Error("eventutil.BuildEvent failed")
 		return spec.InternalServerError()
 	}

internal/eventutil/events.go

@@ -31,7 +31,17 @@ import (
 
 // ErrRoomNoExists is returned when trying to lookup the state of a room that
 // doesn't exist
-var ErrRoomNoExists = errors.New("room does not exist")
+var errRoomNoExists = fmt.Errorf("room does not exist")
+
+type ErrRoomNoExists struct{}
+
+func (e ErrRoomNoExists) Error() string {
+	return errRoomNoExists.Error()
+}
+
+func (e ErrRoomNoExists) Unwrap() error {
+	return errRoomNoExists
+}
 
 // QueryAndBuildEvent builds a Matrix event using the event builder and roomserver query
 // API client provided. If also fills roomserver query API response (if provided)
@@ -116,7 +126,7 @@ func addPrevEventsToEvent(
 	queryRes *api.QueryLatestEventsAndStateResponse,
 ) error {
 	if !queryRes.RoomExists {
-		return ErrRoomNoExists
+		return ErrRoomNoExists{}
 	}
 
 	verImpl, err := gomatrixserverlib.GetRoomVersion(queryRes.RoomVersion)

roomserver/internal/perform/perform_admin.go

@@ -52,7 +52,7 @@ func (r *Admin) PerformAdminEvacuateRoom(
 		return nil, err
 	}
 	if roomInfo == nil || roomInfo.IsStub() {
-		return nil, eventutil.ErrRoomNoExists
+		return nil, eventutil.ErrRoomNoExists{}
 	}
 
 	memberNIDs, err := r.DB.GetMembershipEventNIDsForRoom(ctx, roomInfo.RoomNID, true, true)
@@ -240,7 +240,7 @@ func (r *Admin) PerformAdminDownloadState(
 	}
 
 	if roomInfo == nil || roomInfo.IsStub() {
-		return eventutil.ErrRoomNoExists
+		return eventutil.ErrRoomNoExists{}
 	}
 
 	fwdExtremities, _, depth, err := r.DB.LatestEventIDs(ctx, roomInfo.RoomNID)

roomserver/internal/perform/perform_join.go

@@ -286,7 +286,7 @@ func (r *Joiner) performJoinRoomByID(
 	}
 	event, err := eventutil.QueryAndBuildEvent(ctx, &proto, r.Cfg.Matrix, identity, time.Now(), r.RSAPI, &buildRes)
 
-	switch err {
+	switch err.(type) {
 	case nil:
 		// The room join is local. Send the new join event into the
 		// roomserver. First of all check that the user isn't already
@@ -328,7 +328,7 @@ func (r *Joiner) performJoinRoomByID(
 			// Otherwise we'll try a federated join as normal, since it's quite
 			// possible that the room still exists on other servers.
 			if len(req.ServerNames) == 0 {
-				return "", "", eventutil.ErrRoomNoExists
+				return "", "", eventutil.ErrRoomNoExists{}
 			}
 		}
 

roomserver/internal/perform/perform_upgrade.go

@@ -274,7 +274,7 @@ func publishNewRoomAndUnpublishOldRoom(
 
 func (r *Upgrader) validateRoomExists(ctx context.Context, roomID string) error {
 	if _, err := r.URSAPI.QueryRoomVersionForRoom(ctx, roomID); err != nil {
-		return eventutil.ErrRoomNoExists
+		return eventutil.ErrRoomNoExists{}
 	}
 	return nil
 }
@@ -556,15 +556,18 @@ func (r *Upgrader) makeHeaderedEvent(ctx context.Context, evTime time.Time, user
 	}
 	var queryRes api.QueryLatestEventsAndStateResponse
 	headeredEvent, err := eventutil.QueryAndBuildEvent(ctx, &proto, r.Cfg.Matrix, identity, evTime, r.URSAPI, &queryRes)
-	if err == eventutil.ErrRoomNoExists {
+	switch e := err.(type) {
-		return nil, err
+	case nil:
-	} else if e, ok := err.(gomatrixserverlib.BadJSONError); ok {
+	case eventutil.ErrRoomNoExists:
 		return nil, e
-	} else if e, ok := err.(gomatrixserverlib.EventValidationError); ok {
+	case gomatrixserverlib.BadJSONError:
 		return nil, e
-	} else if err != nil {
+	case gomatrixserverlib.EventValidationError:
+		return nil, e
+	default:
 		return nil, fmt.Errorf("failed to build new %q event: %w", proto.Type, err)
 	}
+
 	// check to see if this user can perform this operation
 	stateEvents := make([]gomatrixserverlib.PDU, len(queryRes.StateEvents))
 	for i := range queryRes.StateEvents {