No Api for languages

src/Squidex.Core/Schemas/Schema.cs

@@ -129,7 +129,7 @@ namespace Squidex.Core.Schemas
 
             if (!fieldsById.TryGetValue(fieldId, out field))
             {
-                throw new DomainObjectNotFoundException(fieldId.ToString(), typeof(Field));
+                throw new DomainObjectNotFoundException(fieldId.ToString(), "Fields", typeof(Field));
             }
 
             var newField = updater(field);

src/Squidex.Infrastructure/Dispatching/ActionContextDispatcher.cs

@@ -21,7 +21,7 @@ namespace Squidex.Infrastructure.Dispatching
         {
             Handlers =
                 typeof(TTarget)
-                    .GetMethods()
+                    .GetMethods(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance)
                     .Where(Helper.HasRightName)
                     .Where(Helper.HasRightParameters<TIn, TContext>)
                     .Select(ActionContextDispatcherFactory.CreateActionHandler<TTarget, TContext>)

src/Squidex.Infrastructure/Dispatching/ActionDispatcher.cs

@@ -21,7 +21,7 @@ namespace Squidex.Infrastructure.Dispatching
         {
             Handlers =
                 typeof(TTarget)
-                    .GetMethods()
+                    .GetMethods(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance)
                     .Where(Helper.HasRightName)
                     .Where(Helper.HasRightParameters<TIn>)
                     .Select(ActionDispatcherFactory.CreateActionHandler<TTarget>)

src/Squidex.Infrastructure/Dispatching/FuncDispatcher.cs

@@ -21,7 +21,7 @@ namespace Squidex.Infrastructure.Dispatching
         {
             Handlers =
                 typeof(TTarget)
-                    .GetMethods()
+                    .GetMethods(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance)
                     .Where(Helper.HasRightName)
                     .Where(Helper.HasRightParameters<TIn>)
                     .Where(Helper.HasRightReturnType<TOut>)

src/Squidex.Store.MongoDb/Apps/MongoAppRepository.cs

@@ -7,7 +7,6 @@
 // ==========================================================================
 
 using System.Collections.Generic;
-using System.Linq;
 using System.Threading.Tasks;
 using MongoDB.Driver;
 using Squidex.Events.Apps;

src/Squidex.Write/Apps/AppDomainObject.cs

@@ -7,21 +7,21 @@
 // ==========================================================================
 
 using System;
+using System.Collections.Generic;
 using Squidex.Core.Apps;
 using Squidex.Events.Apps;
 using Squidex.Infrastructure;
 using Squidex.Infrastructure.CQRS;
+using Squidex.Infrastructure.CQRS.Commands;
 using Squidex.Infrastructure.CQRS.Events;
 using Squidex.Infrastructure.Dispatching;
-using Squidex.Write.Apps.Commands;
-using System.Collections.Generic;
-using Squidex.Infrastructure.CQRS.Commands;
 using Squidex.Infrastructure.Reflection;
+using Squidex.Write.Apps.Commands;
 // ReSharper disable InvertIf
 
 namespace Squidex.Write.Apps
 {
-    public sealed class AppDomainObject : DomainObject
+    public class AppDomainObject : DomainObject
     {
         private static readonly Language DefaultLanguage = Language.GetLanguage("en");
         private readonly AppContributors contributors = new AppContributors();
@@ -44,47 +44,47 @@ namespace Squidex.Write.Apps
         {
         }
 
-        public void On(AppCreated @event)
+        protected void On(AppCreated @event)
         {
             name = @event.Name;
         }
 
-        public void On(AppContributorAssigned @event)
+        protected void On(AppContributorAssigned @event)
         {
             contributors.Assign(@event.ContributorId, @event.Permission);
         }
 
-        public void On(AppContributorRemoved @event)
+        protected void On(AppContributorRemoved @event)
         {
             contributors.Remove(@event.ContributorId);
         }
 
-        public void On(AppClientAttached @event)
+        protected void On(AppClientAttached @event)
         {
             clients.Add(@event.Id, @event.Secret, @event.ExpiresUtc);
         }
 
-        public void On(AppClientRenamed @event)
+        protected void On(AppClientRenamed @event)
         {
             clients.Rename(@event.Id, @event.Name);
         }
 
-        public void On(AppClientRevoked @event)
+        protected void On(AppClientRevoked @event)
         {
             clients.Revoke(@event.Id);
         }
 
-        public void On(AppLanguageAdded @event)
+        protected void On(AppLanguageAdded @event)
         {
             languages.Add(@event.Language);
         }
 
-        public void On(AppLanguageRemoved @event)
+        protected void On(AppLanguageRemoved @event)
         {
             languages.Remove(@event.Language);
         }
 
-        public void On(AppMasterLanguageSet @event)
+        protected void On(AppMasterLanguageSet @event)
         {
             languages.SetMasterLanguage(@event.Language);
         }

src/Squidex.Write/Apps/AppLanguages.cs

@@ -18,11 +18,6 @@ namespace Squidex.Write.Apps
         private readonly HashSet<Language> languages = new HashSet<Language>();
         private Language masterLanguage;
 
-        public IReadOnlyCollection<Language> Languages
-        {
-            get { return languages; }
-        }
-
         public void Add(Language language)
         {
             Func<string> message = () => "Cannot add language";

src/Squidex.Write/Apps/Commands/ConfigureLanguages.cs

@@ -1,26 +0,0 @@
-// ==========================================================================
-//  ConfigureLanguages.cs
-//  Squidex Headless CMS
-// ==========================================================================
-//  Copyright (c) Squidex Group
-//  All rights reserved.
-// ==========================================================================
-
-using System.Collections.Generic;
-using Squidex.Infrastructure;
-
-namespace Squidex.Write.Apps.Commands
-{
-    public sealed class ConfigureLanguages : AppAggregateCommand, IValidatable
-    {
-        public List<Language> Languages { get; set; }
-
-        public void Validate(IList<ValidationError> errors)
-        {
-            if (Languages == null || Languages.Count == 0)
-            {
-                errors.Add(new ValidationError("Languages need at least one element.", nameof(Languages)));
-            }
-        }
-    }
-}

src/Squidex.Write/Schemas/SchemaDomainObject.cs

@@ -50,47 +50,47 @@ namespace Squidex.Write.Schemas
             schema = schema.AddOrUpdateField(registry.CreateField(@event.FieldId, @event.Name, @event.Properties));
         }
 
-        public void On(SchemaCreated @event)
+        protected void On(SchemaCreated @event)
         {
             schema = Schema.Create(@event.Name, @event.Properties);
         }
 
-        public void On(FieldUpdated @event)
+        protected void On(FieldUpdated @event)
         {
             schema = schema.UpdateField(@event.FieldId, @event.Properties);
         }
 
-        public void On(FieldHidden @event)
+        protected void On(FieldHidden @event)
         {
             schema = schema.HideField(@event.FieldId);
         }
 
-        public void On(FieldShown @event)
+        protected void On(FieldShown @event)
         {
             schema = schema.ShowField(@event.FieldId);
         }
 
-        public void On(FieldDisabled @event)
+        protected void On(FieldDisabled @event)
         {
             schema = schema.DisableField(@event.FieldId);
         }
 
-        public void On(FieldEnabled @event)
+        protected void On(FieldEnabled @event)
         {
             schema = schema.EnableField(@event.FieldId);
         }
 
-        public void On(SchemaUpdated @event)
+        protected void On(SchemaUpdated @event)
         {
             schema = schema.Update(@event.Properties);
         }
 
-        public void On(FieldDeleted @event)
+        protected void On(FieldDeleted @event)
         {
             schema = schema.DeleteField(@event.FieldId);
         }
 
-        public void On(SchemaDeleted @event)
+        protected void On(SchemaDeleted @event)
         {
             isDeleted = true;
         }

src/Squidex/Controllers/Api/Apps/AppContributorsController.cs

@@ -66,7 +66,7 @@ namespace Squidex.Controllers.Api.Apps
         /// Assign contributor to app.
         /// </summary>
         /// <param name="app">The name of the app.</param>
-        /// <param name="model">Contributor object that needs to be added to the app.</param>
+        /// <param name="request">Contributor object that needs to be added to the app.</param>
         /// <returns>
         /// 204 => User assigned to app.
         /// 400 => User is already assigned to the app or not found.
@@ -74,10 +74,10 @@ namespace Squidex.Controllers.Api.Apps
         /// </returns>
         [HttpPost]
         [Route("apps/{app}/contributors/")]
-        [ProducesResponseType(typeof(ErrorDto[]), 400)]
-        public async Task<IActionResult> PostContributor(string app, [FromBody] AssignContributorDto model)
+        [ProducesResponseType(typeof(ErrorDto), 400)]
+        public async Task<IActionResult> PostContributor(string app, [FromBody] AssignContributorDto request)
         {
-            await CommandBus.PublishAsync(SimpleMapper.Map(model, new AssignContributor()));
+            await CommandBus.PublishAsync(SimpleMapper.Map(request, new AssignContributor()));
 
             return NoContent();
         }
@@ -93,7 +93,7 @@ namespace Squidex.Controllers.Api.Apps
         /// </returns>
         [HttpDelete]
         [Route("apps/{app}/contributors/{id}/")]
-        [ProducesResponseType(typeof(ErrorDto[]), 400)]
+        [ProducesResponseType(typeof(ErrorDto), 400)]
         public async Task<IActionResult> DeleteContributor(string app, string id)
         {
             await CommandBus.PublishAsync(new RemoveContributor { ContributorId = id });

src/Squidex/Controllers/Api/Apps/AppController.cs

@@ -71,7 +71,7 @@ namespace Squidex.Controllers.Api.Apps
         /// <summary>
         /// Create a new app.
         /// </summary>
-        /// <param name="model">The app object that needs to be added to squidex.</param>
+        /// <param name="request">The app object that needs to be added to squidex.</param>
         /// <returns>
         /// 201 => App created.
         /// 400 => App object is not valid.
@@ -86,9 +86,9 @@ namespace Squidex.Controllers.Api.Apps
         [ProducesResponseType(typeof(EntityCreatedDto), 201)]
         [ProducesResponseType(typeof(ErrorDto), 400)]
         [ProducesResponseType(typeof(ErrorDto), 409)]
-        public async Task<IActionResult> PostApp([FromBody] CreateAppDto model)
+        public async Task<IActionResult> PostApp([FromBody] CreateAppDto request)
         {
-            var command = SimpleMapper.Map(model, new CreateApp());
+            var command = SimpleMapper.Map(request, new CreateApp());
 
             var context = await CommandBus.PublishAsync(command);
             var result = context.Result<Guid>();

src/Squidex/Controllers/Api/Apps/AppLanguagesController.cs

@@ -14,6 +14,7 @@ using NSwag.Annotations;
 using Squidex.Infrastructure.CQRS.Commands;
 using Squidex.Infrastructure.Reflection;
 using Squidex.Controllers.Api.Apps.Models;
+using Squidex.Infrastructure;
 using Squidex.Pipeline;
 using Squidex.Read.Apps.Services;
 using Squidex.Write.Apps.Commands;
@@ -63,26 +64,66 @@ namespace Squidex.Controllers.Api.Apps
         }
 
         /// <summary>
-        /// Configure the app languages.
+        /// Attaches an app language.
         /// </summary>
         /// <param name="app">The name of the app.</param>
-        /// <param name="model">The language configuration for the app.</param>
+        /// <param name="request">The language to add to the app.</param>
         /// <returns>
-        /// 204 => App languages configured.
-        /// 400 => Language configuration is empty or contains an invalid language.
+        /// 201 => App language created.
+        /// 400 => Language is an invalid language.
         /// 404 => App not found.
         /// </returns>
-        /// <remarks>
-        /// The ordering of the languages matterns: When you retrieve a content with a localized content squidex tries
-        /// to resolve the correct language for these properties. When there is no value for a property in the specified language,
-        /// the previous languages from languages list is uses as a fallback. 
-        /// </remarks>
         [HttpPost]
         [Route("apps/{app}/languages/")]
-        [ProducesResponseType(typeof(ErrorDto[]), 400)]
-        public async Task<IActionResult> PostLanguages(string app, [FromBody] ConfigureLanguagesDto model)
+        [ProducesResponseType(typeof(LanguageDto), 201)]
+        [ProducesResponseType(typeof(ErrorDto), 400)]
+        public async Task<IActionResult> PostLanguage(string app, [FromBody] AddLanguageDto request)
         {
-            await CommandBus.PublishAsync(SimpleMapper.Map(model, new ConfigureLanguages()));
+            await CommandBus.PublishAsync(SimpleMapper.Map(request, new AddLanguage()));
+
+            var response = SimpleMapper.Map(request.Language, new LanguageDto());
+
+            return StatusCode(201, response);
+        }
+        
+        /// <summary>
+        /// Updates an app language.
+        /// </summary>
+        /// <param name="app">The name of the app.</param>
+        /// <param name="language">The language to delete from the app.</param>
+        /// <param name="model">The language properties.</param>
+        /// <returns>
+        /// 204 => App language updated.
+        /// 400 => Language is an invalid language.
+        /// 404 => App not found.
+        /// </returns>
+        [HttpPut]
+        [Route("apps/{app}/languages/{language}")]
+        public async Task<IActionResult> Update(string app, string language, [FromBody] SetMasterLanguageDto model)
+        {
+            if (model.IsMasterLanguage)
+            {
+                await CommandBus.PublishAsync(new SetMasterLanguage { Language = Language.GetLanguage(language) });
+            }
+
+            return NoContent();
+        }
+
+        /// <summary>
+        /// Deletes an app language.
+        /// </summary>
+        /// <param name="app">The name of the app.</param>
+        /// <param name="language">The language to delete from the app.</param>
+        /// <returns>
+        /// 204 => App language deleted.
+        /// 400 => Language is an invalid language.
+        /// 404 => App not found.
+        /// </returns>
+        [HttpDelete]
+        [Route("apps/{app}/languages/{language}")]
+        public async Task<IActionResult> DeleteLanguage(string app, string language)
+        {
+            await CommandBus.PublishAsync(new RemoveLanguage { Language = Language.GetLanguage(language) });
 
             return NoContent();
         }

src/Squidex/Controllers/Api/Apps/Models/ConfigureLanguagesDto.cs → src/Squidex/Controllers/Api/Apps/Models/AddLanguageDto.cs

@@ -1,21 +1,22 @@
 // ==========================================================================
-//  ConfigureLanguagesDto.cs
+//  AddLanguageDto.cs
 //  Squidex Headless CMS
 // ==========================================================================
 //  Copyright (c) Squidex Group
 //  All rights reserved.
 // ==========================================================================
 
-using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
 using Squidex.Infrastructure;
 
 namespace Squidex.Controllers.Api.Apps.Models
 {
-    public sealed class ConfigureLanguagesDto
+    public class AddLanguageDto
     {
         /// <summary>
-        /// The list of languages to configure the app.
+        /// The language to add.
         /// </summary>
-        public List<Language> Languages { get; set; }
+        [Required]
+        public Language Language { get; set; }
     }
 }

src/Squidex/Controllers/Api/Apps/Models/SetMasterLanguageDto.cs

@@ -0,0 +1,18 @@
+// ==========================================================================
+//  SetMasterLanguageDto.cs
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex Group
+//  All rights reserved.
+// ==========================================================================
+
+namespace Squidex.Controllers.Api.Apps.Models
+{
+    public class SetMasterLanguageDto
+    {
+        /// <summary>
+        /// Set the value to true to make the language to the master language.
+        /// </summary>
+        public bool IsMasterLanguage { get; set; }
+    }
+}

src/Squidex/Controllers/Api/Schemas/SchemaFieldsController.cs

@@ -36,21 +36,21 @@ namespace Squidex.Controllers.Api.Schemas
         /// </summary>
         /// <param name="app">The name of the app.</param>
         /// <param name="name">The name of the schema.</param>
-        /// <param name="model">The field object that needs to be added to the schema.</param>
+        /// <param name="request">The field object that needs to be added to the schema.</param>
         /// <returns>
-        /// 201 => Field created.
-        /// 409 => Field name already in use.
+        /// 201 => Schema field created.
+        /// 409 => Schema field name already in use.
         /// 404 => App or schema not found.
-        /// 404 => Field properties not valid.
+        /// 404 => Schema field properties not valid.
         /// </returns>
         [HttpPost]
         [Route("apps/{app}/schemas/{name}/fields/")]
         [ProducesResponseType(typeof(EntityCreatedDto), 201)]
         [ProducesResponseType(typeof(ErrorDto), 409)]
         [ProducesResponseType(typeof(ErrorDto), 400)]
-        public async Task<IActionResult> PostField(string app, string name, [FromBody] AddFieldDto model)
+        public async Task<IActionResult> PostField(string app, string name, [FromBody] AddFieldDto request)
         {
-            var command = new AddField { Name = model.Name, Properties = model.Properties.ToProperties() };
+            var command = new AddField { Name = request.Name, Properties = request.Properties.ToProperties() };
 
             var context = await CommandBus.PublishAsync(command);
             var result = context.Result<long>();
@@ -63,20 +63,20 @@ namespace Squidex.Controllers.Api.Schemas
         /// </summary>
         /// <param name="app">The name of the app.</param>
         /// <param name="name">The name of the schema.</param>
-        /// <param name="model">The field object that needs to be added to the schema.</param>
+        /// <param name="request">The field object that needs to be added to the schema.</param>
         /// <returns>
-        /// 204 => Field created.
-        /// 409 => Field name already in use.
+        /// 204 => Schema field created.
+        /// 409 => Schema field name already in use.
         /// 404 => App, schema or field not found.
-        /// 404 => Field properties not valid.
+        /// 404 => Schema field properties not valid.
         /// </returns>
         [HttpPut]
         [Route("apps/{app}/schemas/{name}/fields/{id:long}/")]
         [ProducesResponseType(typeof(ErrorDto), 409)]
         [ProducesResponseType(typeof(ErrorDto), 400)]
-        public async Task<IActionResult> PutField(string app, string name, long id, [FromBody] UpdateFieldDto model)
+        public async Task<IActionResult> PutField(string app, string name, long id, [FromBody] UpdateFieldDto request)
         {
-            var command = new UpdateField { FieldId = id, Properties = model.Properties.ToProperties() };
+            var command = new UpdateField { FieldId = id, Properties = request.Properties.ToProperties() };
 
             await CommandBus.PublishAsync(command);
 
@@ -90,7 +90,7 @@ namespace Squidex.Controllers.Api.Schemas
         /// <param name="name">The name of the schema.</param>
         /// <param name="id">The id of the field to hide.</param>
         /// <returns>
-        /// 400 => Field already hidden.
+        /// 400 => Schema field already hidden.
         /// 204 => Schema field hidden.
         /// 404 => App, schema or field not found.
         /// </returns>
@@ -116,7 +116,7 @@ namespace Squidex.Controllers.Api.Schemas
         /// <param name="name">The name of the schema.</param>
         /// <param name="id">The id of the field to shows.</param>
         /// <returns>
-        /// 400 => Field already visible.
+        /// 400 => Schema field already visible.
         /// 204 => Schema field shown.
         /// 404 => App, schema or field not found.
         /// </returns>
@@ -142,7 +142,7 @@ namespace Squidex.Controllers.Api.Schemas
         /// <param name="name">The name of the schema.</param>
         /// <param name="id">The id of the field to enable.</param>
         /// <returns>
-        /// 400 => Field already enabled.
+        /// 400 => Schema field already enabled.
         /// 204 => Schema field enabled.
         /// 404 => App, schema or field not found.
         /// </returns>
@@ -169,7 +169,7 @@ namespace Squidex.Controllers.Api.Schemas
         /// <param name="name">The name of the schema.</param>
         /// <param name="id">The id of the field to disable.</param>
         /// <returns>
-        /// 400 => Field already disabled.
+        /// 400 => Schema field already disabled.
         /// 204 => Schema field disabled.
         /// 404 => App, schema or field not found.
         /// </returns>

src/Squidex/Controllers/Api/Schemas/SchemasController.cs

@@ -85,7 +85,7 @@ namespace Squidex.Controllers.Api.Schemas
         /// <summary>
         /// Create a new schema.
         /// </summary>
-        /// <param name="model">The schema object that needs to be added to the app.</param>
+        /// <param name="request">The schema object that needs to be added to the app.</param>
         /// <param name="app">The name of the app to create the schema to.</param>
         /// <returns>
         /// 201 => Schema created.  
@@ -97,13 +97,13 @@ namespace Squidex.Controllers.Api.Schemas
         [ProducesResponseType(typeof(EntityCreatedDto), 201)]
         [ProducesResponseType(typeof(ErrorDto), 400)]
         [ProducesResponseType(typeof(ErrorDto), 409)]
-        public async Task<IActionResult> PostSchema(string app, [FromBody] CreateSchemaDto model)
+        public async Task<IActionResult> PostSchema(string app, [FromBody] CreateSchemaDto request)
         {
-            var command = SimpleMapper.Map(model, new CreateSchema { AggregateId = Guid.NewGuid() });
+            var command = SimpleMapper.Map(request, new CreateSchema { AggregateId = Guid.NewGuid() });
 
             await CommandBus.PublishAsync(command);
 
-            return CreatedAtAction(nameof(GetSchema), new { name = model.Name }, new EntityCreatedDto { Id = command.Name });
+            return CreatedAtAction(nameof(GetSchema), new { name = request.Name }, new EntityCreatedDto { Id = command.Name });
         }
 
         /// <summary>
@@ -111,15 +111,15 @@ namespace Squidex.Controllers.Api.Schemas
         /// </summary>
         /// <param name="app">The app where the schema is a part of.</param>
         /// <param name="name">The name of the schema.</param>
-        /// <param name="model">The schema object that needs to updated.</param>
+        /// <param name="request">The schema object that needs to updated.</param>
         /// <returns>
         /// 204 => Schema updated.
         /// </returns>
         [HttpPut]
         [Route("apps/{app}/schemas/{name}/")]
-        public async Task<IActionResult> PutSchema(string app, string name, [FromBody] UpdateSchemaDto model)
+        public async Task<IActionResult> PutSchema(string app, string name, [FromBody] UpdateSchemaDto request)
         {
-            var command = SimpleMapper.Map(model, new UpdateSchema());
+            var command = SimpleMapper.Map(request, new UpdateSchema());
 
             await CommandBus.PublishAsync(command);
 

src/Squidex/Controllers/Api/Users/UsersController.cs

@@ -61,7 +61,7 @@ namespace Squidex.Controllers.Api.Users
         /// <param name="id">The id of the user (GUID).</param>
         /// <returns>
         /// 200 => User found.
-        /// 400 => User not found.
+        /// 404 => User not found.
         /// </returns>
         [HttpGet]
         [Route("users/{id}/")]

tests/Squidex.Write.Tests/Apps/AppCommandHandlerTests.cs

@@ -7,7 +7,6 @@
 // ==========================================================================
 
 using System;
-using System.Collections.Generic;
 using System.Threading.Tasks;
 using FluentAssertions;
 using Moq;

tests/Squidex.Write.Tests/Apps/AppDomainObjectTests.cs

@@ -164,7 +164,7 @@ namespace Squidex.Write.Apps
         }
 
         [Fact]
-        public void AttachClient_should_throw_if_name_already_exists()
+        public void AttachClient_should_throw_if_id_already_exists()
         {
             CreateApp();
 
@@ -191,7 +191,7 @@ namespace Squidex.Write.Apps
         }
 
         [Fact]
-        public void RevokeKey_should_throw_if_not_created()
+        public void RevokeClient_should_throw_if_not_created()
         {
             Assert.Throws<DomainException>(() => sut.RevokeClient(new RevokeClient { Id = "not-found" }));
         }
@@ -230,7 +230,7 @@ namespace Squidex.Write.Apps
         }
 
         [Fact]
-        public void RenameKey_should_throw_if_not_created()
+        public void RenameClient_should_throw_if_not_created()
         {
             Assert.Throws<DomainException>(() => sut.RenameClient(new RenameClient { Id = "not-found", Name = clientNewName }));
         }
@@ -268,6 +268,135 @@ namespace Squidex.Write.Apps
                     });
         }
 
+        [Fact]
+        public void AddLanguage_should_throw_if_not_created()
+        {
+            Assert.Throws<DomainException>(() => sut.AddLanguage(new AddLanguage { Language = Language.GetLanguage("de") }));
+        }
+
+        [Fact]
+        public void AddLanguage_should_throw_if_command_is_not_valid()
+        {
+            CreateApp();
+
+            Assert.Throws<ValidationException>(() => sut.AddLanguage(new AddLanguage()));
+        }
+
+        [Fact]
+        public void AddLanguage_should_throw_if_language_already_exists()
+        {
+            CreateApp();
+
+            Assert.Throws<ValidationException>(() => sut.AddLanguage(new AddLanguage { Language = Language.GetLanguage("en") }));
+        }
+
+        [Fact]
+        public void AddLanguage_should_create_events()
+        {
+            CreateApp();
+
+            sut.AddLanguage(new AddLanguage { Language = Language.GetLanguage("de") });
+
+            sut.GetUncomittedEvents().Select(x => x.Payload).ToArray()
+                .ShouldBeEquivalentTo(
+                    new IEvent[]
+                    {
+                        new AppLanguageAdded { Language = Language.GetLanguage("de") }
+                    });
+        }
+
+        [Fact]
+        public void RemoveLanguage_should_throw_if_not_created()
+        {
+            Assert.Throws<DomainException>(() => sut.RemoveLanguage(new RemoveLanguage { Language = Language.GetLanguage("en") }));
+        }
+
+        [Fact]
+        public void RemoveLanguage_should_throw_if_command_is_not_valid()
+        {
+            CreateApp();
+
+            Assert.Throws<ValidationException>(() => sut.RemoveLanguage(new RemoveLanguage()));
+        }
+
+        [Fact]
+        public void RemoveLanguage_should_throw_if_language_not_found()
+        {
+            CreateApp();
+
+            Assert.Throws<DomainObjectNotFoundException>(() => sut.RemoveLanguage(new RemoveLanguage { Language = Language.GetLanguage("de") }));
+        }
+
+        [Fact]
+        public void RemoveLanguage_should_throw_if_master_language()
+        {
+            CreateApp();
+
+            Assert.Throws<ValidationException>(() => sut.RemoveLanguage(new RemoveLanguage { Language = Language.GetLanguage("en") }));
+        }
+
+        [Fact]
+        public void RemoveLanguage_should_create_events()
+        {
+            CreateApp();
+
+            sut.AddLanguage(new AddLanguage { Language = Language.GetLanguage("de") });
+            sut.RemoveLanguage(new RemoveLanguage { Language = Language.GetLanguage("de") });
+
+            sut.GetUncomittedEvents().Select(x => x.Payload).Skip(1).ToArray()
+                .ShouldBeEquivalentTo(
+                    new IEvent[]
+                    {
+                        new AppLanguageRemoved { Language = Language.GetLanguage("de") }
+                    });
+        }
+
+        [Fact]
+        public void SetMasterLanguage_should_throw_if_not_created()
+        {
+            Assert.Throws<DomainException>(() => sut.SetMasterLanguage(new SetMasterLanguage { Language = Language.GetLanguage("en") }));
+        }
+
+        [Fact]
+        public void SetMasterLanguage_should_throw_if_command_is_not_valid()
+        {
+            CreateApp();
+
+            Assert.Throws<ValidationException>(() => sut.SetMasterLanguage(new SetMasterLanguage()));
+        }
+
+        [Fact]
+        public void SetMasterLanguage_should_throw_if_language_not_found()
+        {
+            CreateApp();
+
+            Assert.Throws<DomainObjectNotFoundException>(() => sut.SetMasterLanguage(new SetMasterLanguage { Language = Language.GetLanguage("de") }));
+        }
+
+        [Fact]
+        public void SetMasterLanguage_should_throw_if_already_master_language()
+        {
+            CreateApp();
+
+            Assert.Throws<ValidationException>(() => sut.SetMasterLanguage(new SetMasterLanguage { Language = Language.GetLanguage("en") }));
+        }
+
+        [Fact]
+        public void SetMasterLanguage_should_create_events()
+        {
+            CreateApp();
+
+            sut.AddLanguage(new AddLanguage { Language = Language.GetLanguage("de") });
+            sut.SetMasterLanguage(new SetMasterLanguage { Language = Language.GetLanguage("de") });
+
+            sut.GetUncomittedEvents().Select(x => x.Payload).Skip(1).ToArray()
+                .ShouldBeEquivalentTo(
+                    new IEvent[]
+                    {
+                        new AppMasterLanguageSet { Language = Language.GetLanguage("de") }
+                    });
+        }
+
         private void CreateApp()
         {
             sut.Create(new CreateApp { Name = TestName, User = user });