add test

osu.Game.Tests/Visual/Gameplay/TestSceneGameplayLeaderboard.cs

@@ -155,7 +155,7 @@ namespace osu.Game.Tests.Visual.Gameplay
                 var api = (DummyAPIAccess)API;
 
                 api.Friends.Clear();
-                api.Friends.Add(friend);
+                api.Friends.Add(CreateAPIRelationFromAPIUser(friend));
             });
 
             int playerNumber = 1;

osu.Game.Tests/Visual/Online/TestSceneDashboardOverlay.cs

@@ -30,7 +30,7 @@ namespace osu.Game.Tests.Visual.Online
                 if (supportLevel > 3)
                     supportLevel = 0;
 
-                ((DummyAPIAccess)API).Friends.Add(new APIUser
+                ((DummyAPIAccess)API).Friends.Add(CreateAPIRelationFromAPIUser(new APIUser
                 {
                     Username = @"peppy",
                     Id = 2,
@@ -38,7 +38,7 @@ namespace osu.Game.Tests.Visual.Online
                     CoverUrl = @"https://osu.ppy.sh/images/headers/profile-covers/c3.jpg",
                     IsSupporter = supportLevel > 0,
                     SupportLevel = supportLevel
-                });
+                }));
             }
         }
 

osu.Game.Tests/Visual/Online/TestSceneUserProfileHeader.cs

@@ -3,17 +3,24 @@
 
 using System;
 using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
 using NUnit.Framework;
 using osu.Framework.Allocation;
+using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Testing;
 using osu.Game.Configuration;
 using osu.Game.Graphics.Containers;
+using osu.Game.Online.API;
+using osu.Game.Online.API.Requests;
 using osu.Game.Online.API.Requests.Responses;
 using osu.Game.Overlays;
 using osu.Game.Overlays.Profile;
+using osu.Game.Overlays.Profile.Header.Components;
 using osu.Game.Rulesets.Osu;
 using osu.Game.Users;
+using osuTK.Input;
 
 namespace osu.Game.Tests.Visual.Online
 {
@@ -22,6 +29,10 @@ namespace osu.Game.Tests.Visual.Online
         [Cached]
         private readonly OverlayColourProvider colourProvider = new OverlayColourProvider(OverlayColourScheme.Green);
 
+        private DummyAPIAccess dummyAPI => (DummyAPIAccess)API;
+
+        private readonly ManualResetEventSlim requestLock = new ManualResetEventSlim();
+
         [Resolved]
         private OsuConfigManager configManager { get; set; } = null!;
 
@@ -400,5 +411,74 @@ namespace osu.Game.Tests.Visual.Online
                 }
             }, new OsuRuleset().RulesetInfo));
         }
+
+        [Test]
+        public void TestAddFriend()
+        {
+            AddStep("clear friend list", () => dummyAPI.Friends.Clear());
+            AddStep("Show non-friend user", () => header.User.Value = new UserProfileData(TestSceneUserProfileOverlay.TEST_USER, new OsuRuleset().RulesetInfo));
+            AddStep("Setup request", () =>
+            {
+                requestLock.Reset();
+
+                dummyAPI.HandleRequest += request =>
+                {
+                    if (request is not FriendAddRequest req)
+                        return false;
+
+                    if (req.TargetId != 1)
+                        return false;
+
+                    var apiRelation = CreateAPIRelationFromAPIUser(TestSceneUserProfileOverlay.TEST_USER);
+
+                    Task.Run(() =>
+                    {
+                        requestLock.Wait(3000);
+                        req.TriggerSuccess(apiRelation);
+                    });
+
+                    dummyAPI.Friends.Add(apiRelation);
+                    return true;
+                };
+            });
+            AddStep("Click followers button", () => this.ChildrenOfType<FollowersButton>().First().TriggerClick());
+            AddStep("Complete request", () => requestLock.Set());
+            AddUntilStep("Friend added", () => API.Friends.Any(f => f.TargetID == TestSceneUserProfileOverlay.TEST_USER.OnlineID));
+        }
+
+        [Test]
+        public void TestAddFriendNonMutual()
+        {
+            AddStep("clear friend list", () => dummyAPI.Friends.Clear());
+            AddStep("Show non-friend user", () => header.User.Value = new UserProfileData(TestSceneUserProfileOverlay.TEST_USER, new OsuRuleset().RulesetInfo));
+            AddStep("Setup request", () =>
+            {
+                requestLock.Reset();
+
+                dummyAPI.HandleRequest += request =>
+                {
+                    if (request is not FriendAddRequest req)
+                        return false;
+
+                    if (req.TargetId != 1)
+                        return false;
+
+                    var apiRelation = CreateAPIRelationFromAPIUser(TestSceneUserProfileOverlay.TEST_USER);
+                    apiRelation.Mutual = false;
+
+                    Task.Run(() =>
+                    {
+                        requestLock.Wait(3000);
+                        req.TriggerSuccess(apiRelation);
+                    });
+
+                    dummyAPI.Friends.Add(apiRelation);
+                    return true;
+                };
+            });
+            AddStep("Click followers button", () => this.ChildrenOfType<FollowersButton>().First().TriggerClick());
+            AddStep("Complete request", () => requestLock.Set());
+            AddUntilStep("Friend added", () => API.Friends.Any(f => f.TargetID == TestSceneUserProfileOverlay.TEST_USER.OnlineID));
+        }
     }
 }

osu.Game/Online/API/Requests/FriendAddRequest.cs

@@ -9,11 +9,11 @@ namespace osu.Game.Online.API.Requests
 {
     public class FriendAddRequest : APIRequest<APIRelation>
     {
-        private readonly int targetId;
+        public readonly int TargetId;
 
         public FriendAddRequest(int targetId)
         {
-            this.targetId = targetId;
+            TargetId = targetId;
         }
 
         protected override WebRequest CreateWebRequest()
@@ -21,7 +21,7 @@ namespace osu.Game.Online.API.Requests
             var req = base.CreateWebRequest();
 
             req.Method = HttpMethod.Post;
-            req.AddParameter("target", targetId.ToString(), RequestParameterType.Query);
+            req.AddParameter("target", TargetId.ToString(), RequestParameterType.Query);
 
             return req;
         }

osu.Game/Online/API/Requests/FriendDeleteRequest.cs

@@ -8,11 +8,11 @@ namespace osu.Game.Online.API.Requests
 {
     public class FriendDeleteRequest : APIRequest
     {
-        private readonly int targetId;
+        public readonly int TargetId;
 
         public FriendDeleteRequest(int targetId)
         {
-            this.targetId = targetId;
+            TargetId = targetId;
         }
 
         protected override WebRequest CreateWebRequest()
@@ -22,6 +22,6 @@ namespace osu.Game.Online.API.Requests
             return req;
         }
 
-        protected override string Target => $@"friends/{targetId}";
+        protected override string Target => $@"friends/{TargetId}";
     }
 }

osu.Game/Overlays/Profile/Header/Components/FollowersButton.cs

@@ -37,7 +37,7 @@ namespace osu.Game.Overlays.Profile.Header.Components
         private OverlayColourProvider colourProvider { get; set; } = null!;
 
         [BackgroundDependencyLoader]
-        private void load(IAPIProvider api, INotificationOverlay notifications)
+        private void load(IAPIProvider api, INotificationOverlay? notifications)
         {
             localUser.BindTo(api.LocalUser);
 

osu.Game/Tests/Visual/OsuTestScene.cs

@@ -317,6 +317,15 @@ namespace osu.Game.Tests.Visual
             return result;
         }
 
+        public static APIRelation CreateAPIRelationFromAPIUser(APIUser user) =>
+            new APIRelation
+            {
+                Mutual = true,
+                RelationType = RelationType.Friend,
+                TargetID = user.OnlineID,
+                TargetUser = user
+            };
+
         protected WorkingBeatmap CreateWorkingBeatmap(RulesetInfo ruleset) =>
             CreateWorkingBeatmap(CreateBeatmap(ruleset));