roomserver/alias: Add test cases, load from DB if appserviceAPI says AliasExists

Signed-off-by: Serra Allgood <serra@allgood.dev>

roomserver/alias/alias.go

@@ -84,6 +84,19 @@ func (r *RoomserverAliasAPI) SetRoomAlias(
 	return r.sendUpdatedAliasesEvent(context.TODO(), request.UserID, request.RoomID)
 }
 
+func getRoomIDFromDB(
+	ctx context.Context,
+	db RoomserverAliasAPIDatabase,
+	request *roomserverAPI.GetRoomIDForAliasRequest,
+) (string, error) {
+	roomID, err := db.GetRoomIDForAlias(ctx, request.Alias)
+	if err != nil {
+		return "", err
+	}
+
+	return roomID, nil
+}
+
 // GetRoomIDForAlias implements alias.RoomserverAliasAPI
 func (r *RoomserverAliasAPI) GetRoomIDForAlias(
 	ctx context.Context,
@@ -91,12 +104,12 @@ func (r *RoomserverAliasAPI) GetRoomIDForAlias(
 	response *roomserverAPI.GetRoomIDForAliasResponse,
 ) error {
 	// Look up the room ID in the database
-	roomID, err := r.DB.GetRoomIDForAlias(ctx, request.Alias)
+	roomID, err := getRoomIDFromDB(ctx, r.DB, request)
 	if err != nil {
 		return err
 	}
 
-	if len(roomID) == 0 {
+	if roomID == "" {
 		// No rooms found locally, try our application services by making a call to
 		// the appservice component
 		aliasReq := appserviceAPI.RoomAliasExistsRequest{Alias: request.Alias}
@@ -104,6 +117,13 @@ func (r *RoomserverAliasAPI) GetRoomIDForAlias(
 		if err = r.AppserviceAPI.RoomAliasExists(ctx, &aliasReq, &aliasResp); err != nil {
 			return err
 		}
+
+		if aliasResp.AliasExists {
+			roomID, err = getRoomIDFromDB(ctx, r.DB, request)
+			if err != nil {
+				return err
+			}
+		}
 	}
 
 	response.RoomID = roomID

src/github.com/matrix-org/dendrite/roomserver/alias/alias_test.go

@@ -1,4 +1,4 @@
-// Copyright 2017 Vector Creations Ltd
+// Copyright 2019 Serra Allgood
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -17,20 +17,21 @@ package alias
 import (
 	"context"
 	"fmt"
+	"strings"
 	"testing"
 
 	appserviceAPI "github.com/matrix-org/dendrite/appservice/api"
 	roomserverAPI "github.com/matrix-org/dendrite/roomserver/api"
 )
 
-type MockRoomserverAliasAPIDatabase struct{}
-
-func (db MockRoomserverAliasAPIDatabase) SetRoomAlias(ctx context.Context, alias string, roomID string) error {
-	return nil
+type MockRoomserverAliasAPIDatabase struct {
+	methodModes map[string]string
+	attempts    int
 }
 
-func (db MockRoomserverAliasAPIDatabase) GetRoomIDForAlias(ctx context.Context, alias string) (string, error) {
-	return "123", nil
+// Those methods can be essentially noop
+func (db MockRoomserverAliasAPIDatabase) SetRoomAlias(ctx context.Context, alias string, roomID string) error {
+	return nil
 }
 
 func (db MockRoomserverAliasAPIDatabase) GetAliasesForRoomID(ctx context.Context, roomID string) ([]string, error) {
@@ -42,8 +43,36 @@ func (db MockRoomserverAliasAPIDatabase) RemoveRoomAlias(ctx context.Context, al
 	return nil
 }
 
-type MockAppServiceQueryAPI struct{}
+// This method needs to change depending on test case
+func (db MockRoomserverAliasAPIDatabase) GetRoomIDForAlias(ctx context.Context, alias string) (string, error) {
+	switch db.methodModes["GetRoomIDForAlias"] {
+	case "empty":
+		return "", nil
+	case "error":
+		return "", fmt.Errorf("found an error from GetRoomIDForAlias")
+	case "found":
+		return "123", nil
+	case "emptyFound":
+		switch db.attempts {
+		case 0:
+			db.attempts = 1
+			return "", nil
+		case 1:
+			db.attempts = 0
+			return "123", nil
+		default:
+			return "", nil
+		}
+	default:
+		return "", fmt.Errorf("Unknown option used")
+	}
+}
 
+type MockAppServiceQueryAPI struct {
+	methodModes map[string]string
+}
+
+// This method can be noop
 func (q MockAppServiceQueryAPI) UserIDExists(
 	ctx context.Context,
 	req *appserviceAPI.UserIDExistsRequest,
@@ -57,26 +86,48 @@ func (q MockAppServiceQueryAPI) RoomAliasExists(
 	req *appserviceAPI.RoomAliasExistsRequest,
 	resp *appserviceAPI.RoomAliasExistsResponse,
 ) error {
-	return fmt.Errorf("Should not have called this")
+	switch q.methodModes["RoomAliasExists"] {
+	case "error":
+		return fmt.Errorf("found an error from RoomAliasExists")
+	case "found":
+		resp.AliasExists = true
+		return nil
+	case "empty":
+		resp.AliasExists = false
+		return nil
+	default:
+		return fmt.Errorf("Unknown option used")
+	}
 }
 
 func TestGetRoomIDForAlias(t *testing.T) {
-	type args struct {
+	type arguments struct {
 		ctx      context.Context
 		request  *roomserverAPI.GetRoomIDForAliasRequest
 		response *roomserverAPI.GetRoomIDForAliasResponse
 	}
 
+	args := arguments{
+		context.Background(),
+		&roomserverAPI.GetRoomIDForAliasRequest{},
+		&roomserverAPI.GetRoomIDForAliasResponse{},
+	}
+
+	setup := func(modes map[string]string) *RoomserverAliasAPI {
+		mockAliasAPIDB := MockRoomserverAliasAPIDatabase{modes, 0}
+		mockAppServiceQueryAPI := MockAppServiceQueryAPI{modes}
+
+		return &RoomserverAliasAPI{
+			DB:            mockAliasAPIDB,
+			AppserviceAPI: mockAppServiceQueryAPI,
+		}
+	}
+
 	t.Run("Found local alias", func(t *testing.T) {
-		aliasAPI := &RoomserverAliasAPI{
-			DB:            MockRoomserverAliasAPIDatabase{},
-			AppserviceAPI: MockAppServiceQueryAPI{},
-		}
-		args := args{
-			context.Background(),
-			&roomserverAPI.GetRoomIDForAliasRequest{},
-			&roomserverAPI.GetRoomIDForAliasResponse{},
-		}
+		methodModes := make(map[string]string)
+		methodModes["GetRoomIDForAlias"] = "found"
+		methodModes["RoomAliasExists"] = "error"
+		aliasAPI := setup(methodModes)
 
 		err := aliasAPI.GetRoomIDForAlias(args.ctx, args.request, args.response)
 		if err != nil {
@@ -87,4 +138,61 @@ func TestGetRoomIDForAlias(t *testing.T) {
 			t.Errorf("Got %s; wanted 123", args.response.RoomID)
 		}
 	})
+
+	t.Run("found appservice alias", func(t *testing.T) {
+		methodModes := make(map[string]string)
+		methodModes["GetRoomIDForAlias"] = "emptyFound"
+		methodModes["RoomAliasExists"] = "found"
+		aliasAPI := setup(methodModes)
+
+		if err := aliasAPI.GetRoomIDForAlias(args.ctx, args.request, args.response); err != nil {
+			t.Fatalf("Got %s; wanted no error", err)
+		}
+
+		if args.response.RoomID != "123" {
+			t.Errorf("Got %s; wanted 123", args.response.RoomID)
+		}
+	})
+
+	t.Run("error returned from DB", func(t *testing.T) {
+		methodModes := make(map[string]string)
+		methodModes["GetRoomIDForAlias"] = "error"
+		aliasAPI := setup(methodModes)
+
+		err := aliasAPI.GetRoomIDForAlias(args.ctx, args.request, args.response)
+		if err == nil {
+			t.Fatalf("Got no error; wanted error from DB")
+		} else if !strings.Contains(err.Error(), "GetRoomIDForAlias") {
+			t.Errorf("Got %s; wanted error from GetRoomIDForAlias", err)
+		}
+	})
+
+	t.Run("error returned from appserviceAPI", func(t *testing.T) {
+		methodModes := make(map[string]string)
+		methodModes["GetRoomIDForAlias"] = "empty"
+		methodModes["RoomAliasExists"] = "error"
+		aliasAPI := setup(methodModes)
+
+		err := aliasAPI.GetRoomIDForAlias(args.ctx, args.request, args.response)
+		if err == nil {
+			t.Fatalf("Got no error; wanted error from appserviceAPI")
+		} else if !strings.Contains(err.Error(), "RoomAliasExists") {
+			t.Errorf("Got %s; wanted error from RoomAliasExists", err)
+		}
+	})
+
+	t.Run("no errors but no alias", func(t *testing.T) {
+		methodModes := make(map[string]string)
+		methodModes["GetRoomIDForAlias"] = "empty"
+		methodModes["RoomAliasExists"] = "empty"
+		aliasAPI := setup(methodModes)
+		args.response.RoomID = "Should be empty"
+
+		if err := aliasAPI.GetRoomIDForAlias(args.ctx, args.request, args.response); err != nil {
+			t.Fatalf("Got %s; wanted no error", err)
+		}
+		if args.response.RoomID != "" {
+			t.Errorf("response.RoomID should have been empty")
+		}
+	})
 }