Add group users limit verification

Src/DeUrgenta.Api/Startup.cs

@@ -46,7 +46,7 @@ public void ConfigureServices(IServiceCollection services)
             services.AddDatabase<DeUrgentaContext>(Configuration.GetConnectionString("DbConnectionString"));
             services.AddExceptionHandling(WebHostEnvironment);
 
-            services.AddUserApiServices();
+            services.AddUserApiServices(Configuration);
             services.AddBackpackApiServices();
             services.AddGroupApiServices(Configuration);
             services.AddCertificationsApiServices();         

Src/DeUrgenta.Api/appsettings.json

@@ -47,7 +47,8 @@
   },
   "Group": {
     "MaxJoinedGroupsPerUser": 5,
-    "MaxCreatedGroupsPerUser": 5
+    "MaxCreatedGroupsPerUser": 5,
+    "UsersLimit": 30
   },
   "Passwords": {
     "RequiredLength": 6,

Src/DeUrgenta.User.Api/BootstrappingExtensions.cs

@@ -116,8 +116,10 @@ public static void SetupEmailService(this IServiceCollection services, IConfigur
             }
         }
 
-        public static IServiceCollection AddUserApiServices(this IServiceCollection services)
+        public static IServiceCollection AddUserApiServices(this IServiceCollection services, IConfiguration configuration)
         {
+            services.Configure<GroupsConfig>(configuration.GetSection(GroupsConfig.SectionName));
+
             services.AddTransient<IValidateRequest<GetUser>, GetUserValidator>();
             services.AddTransient<IValidateRequest<UpdateUser>, UpdateUserValidator>();
             services.AddTransient<IValidateRequest<GetBackpackInvites>, GetBackpackInvitesValidator>();

Src/DeUrgenta.User.Api/Options/GroupsConfig.cs

@@ -0,0 +1,8 @@
+namespace DeUrgenta.User.Api.Options
+{
+    public class GroupsConfig
+    {
+        public const string SectionName = "Group";
+        public int UsersLimit { get; set; }
+    }
+}

Src/DeUrgenta.User.Api/Validators/AcceptGroupInviteValidator.cs

@@ -1,18 +1,23 @@
-using System.Threading.Tasks;
+using System.Linq;
+using System.Threading.Tasks;
 using DeUrgenta.Common.Validation;
 using DeUrgenta.Domain;
 using DeUrgenta.User.Api.Commands;
+using DeUrgenta.User.Api.Options;
 using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Options;
 
 namespace DeUrgenta.User.Api.Validators
 {
     public class AcceptGroupInviteValidator : IValidateRequest<AcceptGroupInvite>
     {
         private readonly DeUrgentaContext _context;
+        private readonly IOptions<GroupsConfig> _options;
 
-        public AcceptGroupInviteValidator(DeUrgentaContext context)
+        public AcceptGroupInviteValidator(DeUrgentaContext context, IOptions<GroupsConfig> options)
         {
             _context = context;
+            _options = options;
         }
 
         public async Task<bool> IsValidAsync(AcceptGroupInvite request)
@@ -24,11 +29,29 @@ public async Task<bool> IsValidAsync(AcceptGroupInvite request)
                 return false;
             }
 
-            var inviteExists = await _context
+            var invite = await _context
                 .GroupInvites
-                .AnyAsync(bi => bi.InvitationReceiver.Sub == request.UserSub && bi.Id == request.GroupInviteId);
+                .FirstOrDefaultAsync(bi => bi.InvitationReceiver.Sub == request.UserSub && bi.Id == request.GroupInviteId);
 
-            return inviteExists;
+            if (invite is null)
+            {
+                return false;
+            }
+
+            var config = _options.Value;
+
+            var exceedsLimit = await _context.UsersToGroups
+                .Where(x => x.GroupId == invite.GroupId)
+                .GroupBy(x => x.GroupId)
+                .Where(g => g.Count() >= config.UsersLimit)
+                .AnyAsync();
+
+            if (exceedsLimit)
+            {
+                return false;
+            }
+
+            return true;
         }
     }
 }

Src/Tests/DeUrgenta.User.Api.Tests/Validators/AcceptGroupInviteValidator.cs

@@ -5,8 +5,11 @@
 using DeUrgenta.Tests.Helpers;
 using DeUrgenta.Tests.Helpers.Builders;
 using DeUrgenta.User.Api.Commands;
+using DeUrgenta.User.Api.Options;
 using DeUrgenta.User.Api.Validators;
 using FluentAssertions;
+using Microsoft.Extensions.Options;
+using NSubstitute;
 using Xunit;
 
 namespace DeUrgenta.User.Api.Tests.Validators
@@ -15,10 +18,11 @@ namespace DeUrgenta.User.Api.Tests.Validators
     public class AcceptGroupInviteValidatorShould
     {
         private readonly DeUrgentaContext _dbContext;
-
+        private readonly IOptions<GroupsConfig> _defaultOptions = Substitute.For<IOptions<GroupsConfig>>();
         public AcceptGroupInviteValidatorShould(DatabaseFixture fixture)
         {
             _dbContext = fixture.Context;
+            _defaultOptions.Value.Returns(new GroupsConfig { UsersLimit = 30 });
         }
 
         [Theory]
@@ -28,7 +32,7 @@ public AcceptGroupInviteValidatorShould(DatabaseFixture fixture)
         public async Task Invalidate_request_when_no_user_found_by_sub(string sub)
         {
             // Arrange
-            var sut = new AcceptGroupInviteValidator(_dbContext);
+            var sut = new AcceptGroupInviteValidator(_dbContext, _defaultOptions);
 
             // Act
             var isValid = await sut.IsValidAsync(new AcceptGroupInvite(sub, Guid.NewGuid()));
@@ -40,7 +44,7 @@ public async Task Invalidate_request_when_no_user_found_by_sub(string sub)
         [Fact]
         public async Task Invalidate_when_invite_is_for_other_user()
         {
-            var sut = new AcceptGroupInviteValidator(_dbContext);
+            var sut = new AcceptGroupInviteValidator(_dbContext, _defaultOptions);
 
             // Arrange
             var userSub = Guid.NewGuid().ToString();
@@ -84,7 +88,7 @@ public async Task Invalidate_when_invite_is_for_other_user()
         [Fact]
         public async Task Invalidate_when_invite_does_not_exist()
         {
-            var sut = new AcceptGroupInviteValidator(_dbContext);
+            var sut = new AcceptGroupInviteValidator(_dbContext, _defaultOptions);
 
             // Arrange
             var userSub = Guid.NewGuid().ToString();
@@ -113,10 +117,57 @@ public async Task Invalidate_when_invite_does_not_exist()
             isValid.Should().BeFalse();
         }
 
+        [Fact]
+        public async Task Invalidate_when_exceeds_group_users_limit()
+        {
+            var options = Substitute.For<IOptions<GroupsConfig>>();
+            options.Value.Returns(new GroupsConfig { UsersLimit = 2 });
+            var sut = new AcceptGroupInviteValidator(_dbContext, options);
+
+            // Arrange
+            var userSub = Guid.NewGuid().ToString();
+            var user = new UserBuilder().WithSub(userSub).Build();
+
+            var secondUserSub = Guid.NewGuid().ToString();
+            var secondUser = new UserBuilder().WithSub(secondUserSub).Build();
+
+            var adminSub = Guid.NewGuid().ToString();
+            var admin = new UserBuilder().WithSub(adminSub).Build();
+
+            await _dbContext.Users.AddAsync(user);
+            await _dbContext.Users.AddAsync(admin);
+
+            var group = new Group
+            {
+                Admin = admin,
+                Name = "group"
+            };
+
+            await _dbContext.UsersToGroups.AddAsync(new UserToGroup { Group = group, User = admin });
+            await _dbContext.UsersToGroups.AddAsync(new UserToGroup { Group = group, User = user });
+
+            var groupInvite = new GroupInvite
+            {
+                InvitationReceiver = secondUser,
+                InvitationSender = admin,
+                Group = group
+            };
+            await _dbContext.GroupInvites.AddAsync(groupInvite);
+            await _dbContext.Groups.AddAsync(group);
+
+            await _dbContext.SaveChangesAsync();
+
+            // Act
+            var isValid = await sut.IsValidAsync(new AcceptGroupInvite(secondUserSub, groupInvite.Id));
+
+            // Assert
+            isValid.Should().BeFalse();
+        }
+
         [Fact]
         public async Task Validate_when_an_invite_exists()
         {
-            var sut = new AcceptGroupInviteValidator(_dbContext);
+            var sut = new AcceptGroupInviteValidator(_dbContext, _defaultOptions);
 
             // Arrange
             var userSub = Guid.NewGuid().ToString();