Prevent creation of duplicate genres via the UI

src/MusicCatalogue.Api/Controllers/AlbumsController.cs

@@ -92,7 +92,7 @@ public async Task<ActionResult<IEnumerable<Album>>> GetAlbumsAsync([FromBody] Al
         public async Task<ActionResult<Album>> AddAlbumAsync([FromBody] Album template)
         {
             // Make sure the "other" Genre exists as a fallback for album updates where no genre is given
-            var otherGenre = _factory.Genres.AddAsync(OtherGenre);
+            var otherGenre = _factory.Genres.AddAsync(OtherGenre, false);
 
             // Add the album
             var album = await _factory.Albums.AddAsync(
@@ -120,7 +120,7 @@ public async Task<ActionResult<Album>> AddAlbumAsync([FromBody] Album template)
         public async Task<ActionResult<Album>> UpdateAlbumAsync([FromBody] Album template)
         {
             // Make sure the "other" Genre exists as a fallback for album updates where no genre is given
-            var otherGenre = _factory.Genres.AddAsync(OtherGenre);
+            var otherGenre = _factory.Genres.AddAsync(OtherGenre, false);
 
             // Attempt the update
             var album = await _factory.Albums.UpdateAsync(

src/MusicCatalogue.Api/Controllers/GenresController.cs

@@ -72,7 +72,7 @@ public async Task<ActionResult<Genre>> GetGenreByIdAsync(int id)
         [Route("")]
         public async Task<ActionResult<Genre>> AddGenreAsync([FromBody] Genre template)
         {
-            var genre = await _factory.Genres.AddAsync(template.Name);
+            var genre = await _factory.Genres.AddAsync(template.Name, true);
             return genre;
         }
 

src/MusicCatalogue.Api/MusicCatalogue.Api.csproj

@@ -2,9 +2,9 @@
 
   <PropertyGroup>
     <TargetFramework>net8.0</TargetFramework>
-    <ReleaseVersion>1.33.0.0</ReleaseVersion>
-    <FileVersion>1.33.0.0</FileVersion>
-    <ProductVersion>1.33.0</ProductVersion>
+    <ReleaseVersion>1.34.0.0</ReleaseVersion>
+    <FileVersion>1.34.0.0</FileVersion>
+    <ProductVersion>1.34.0</ProductVersion>
     <Nullable>enable</Nullable>
     <ImplicitUsings>enable</ImplicitUsings>
   </PropertyGroup>

src/MusicCatalogue.Data/MusicCatalogue.Data.csproj

@@ -5,7 +5,7 @@
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <PackageId>MusicCatalogue.Data</PackageId>
-    <PackageVersion>1.24.0.0</PackageVersion>
+    <PackageVersion>1.25.0.0</PackageVersion>
     <Authors>Dave Walker</Authors>
     <Copyright>Copyright (c) Dave Walker 2023</Copyright>
     <Owners>Dave Walker</Owners>
@@ -17,7 +17,7 @@
     <PackageProjectUrl>https://github.com/davewalker5/MusicCatalogue</PackageProjectUrl>
     <PackageLicenseExpression>MIT</PackageLicenseExpression>
     <PackageRequireLicenseAcceptance>false</PackageRequireLicenseAcceptance>
-    <ReleaseVersion>1.24.0.0</ReleaseVersion>
+    <ReleaseVersion>1.25.0.0</ReleaseVersion>
   </PropertyGroup>
 
   <ItemGroup>

src/MusicCatalogue.Entities/Exceptions/DuplicateGenreException.cs

@@ -0,0 +1,21 @@
+using System.Diagnostics.CodeAnalysis;
+
+namespace MusicCatalogue.Entities.Exceptions
+{
+    [Serializable]
+    [ExcludeFromCodeCoverage]
+    public class DuplicateGenreException : Exception
+    {
+        public DuplicateGenreException()
+        {
+        }
+
+        public DuplicateGenreException(string message) : base(message)
+        {
+        }
+
+        public DuplicateGenreException(string message, Exception inner) : base(message, inner)
+        {
+        }
+    }
+}

src/MusicCatalogue.Entities/Exceptions/GenreNotFoundException.cs

@@ -0,0 +1,21 @@
+using System.Diagnostics.CodeAnalysis;
+
+namespace MusicCatalogue.Entities.Exceptions
+{
+    [Serializable]
+    [ExcludeFromCodeCoverage]
+    public class GenreNotFoundException : Exception
+    {
+        public GenreNotFoundException()
+        {
+        }
+
+        public GenreNotFoundException(string message) : base(message)
+        {
+        }
+
+        public GenreNotFoundException(string message, Exception inner) : base(message, inner)
+        {
+        }
+    }
+}

src/MusicCatalogue.Entities/Interfaces/IGenreManager.cs

@@ -5,7 +5,7 @@ namespace MusicCatalogue.Entities.Interfaces
 {
     public interface IGenreManager
     {
-        Task<Genre> AddAsync(string name);
+        Task<Genre> AddAsync(string name, bool raiseErrorIfExists);
         Task<Genre> GetAsync(Expression<Func<Genre, bool>> predicate);
         Task<List<Genre>> ListAsync(Expression<Func<Genre, bool>> predicate);
         Task<Genre?> UpdateAsync(int genreId, string name);

src/MusicCatalogue.Entities/MusicCatalogue.Entities.csproj

@@ -5,7 +5,7 @@
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <PackageId>MusicCatalogue.Entities</PackageId>
-    <PackageVersion>1.24.0.0</PackageVersion>
+    <PackageVersion>1.25.0.0</PackageVersion>
     <Authors>Dave Walker</Authors>
     <Copyright>Copyright (c) Dave Walker 2023</Copyright>
     <Owners>Dave Walker</Owners>
@@ -17,7 +17,7 @@
     <PackageProjectUrl>https://github.com/davewalker5/MusicCatalogue</PackageProjectUrl>
     <PackageLicenseExpression>MIT</PackageLicenseExpression>
     <PackageRequireLicenseAcceptance>false</PackageRequireLicenseAcceptance>
-    <ReleaseVersion>1.24.0.0</ReleaseVersion>
+    <ReleaseVersion>1.25.0.0</ReleaseVersion>
   </PropertyGroup>
 
   <ItemGroup>

src/MusicCatalogue.Logic/Collection/AlbumLookupManager.cs

@@ -79,7 +79,7 @@ private async Task<Album> StoreAlbumLocally(string artistName, Album template, b
             // Save the artist details, first. As with all the database calls in this method, the
             // logic to prevent duplication of artistsand genres is in the management class
             var artist = await _factory.Artists.AddAsync(artistName);
-            var genre = await _factory.Genres.AddAsync(template.Genre!.Name);
+            var genre = await _factory.Genres.AddAsync(template.Genre!.Name, false);
 
             // Save the album details
             var album = await _factory.Albums.AddAsync(

src/MusicCatalogue.Logic/DataExchange/Catalogue/CatalogueCsvImporter.cs

@@ -47,7 +47,7 @@ public async Task Import(string file)
                             // Inflate the CSV record to a track and save the artist and genre
                             var track = FlattenedTrack.FromCsv(fields!);
                             var artist = await _factory.Artists.AddAsync(track.ArtistName);
-                            var genre = await _factory.Genres.AddAsync(track.Genre!);
+                            var genre = await _factory.Genres.AddAsync(track.Genre!, false);
 
                             // Add the retailer
                             int? retailerId = null;

src/MusicCatalogue.Logic/Database/GenreManager.cs

@@ -41,8 +41,9 @@ public async Task<List<Genre>> ListAsync(Expression<Func<Genre, bool>> predicate
         /// Add a genre, if it doesn't already exist
         /// </summary>
         /// <param name="name"></param>
+        /// <param name="raiseErrorIfExists"></param>
         /// <returns></returns>
-        public async Task<Genre> AddAsync(string name)
+        public async Task<Genre> AddAsync(string name, bool raiseErrorIfExists)
         {
             var clean = StringCleaner.Clean(name)!;
             var genre = await GetAsync(a => a.Name == clean);
@@ -56,6 +57,11 @@ public async Task<Genre> AddAsync(string name)
                 await Context.Genres.AddAsync(genre);
                 await Context.SaveChangesAsync();
             }
+            else if (raiseErrorIfExists)
+            {
+                var message = $"Cannot create duplicate genre {genre.Name}";
+                throw new DuplicateGenreException(message);
+            }
 
             return genre;
         }
@@ -74,6 +80,11 @@ public async Task<Genre> AddAsync(string name)
                 genre.Name = StringCleaner.Clean(name)!;
                 await Context.SaveChangesAsync();
             }
+            else
+            {
+                var message = $"Genre '{name}' not found";
+                throw new GenreNotFoundException(message);
+            }
             return genre;
         }
 

src/MusicCatalogue.Logic/MusicCatalogue.Logic.csproj

@@ -5,7 +5,7 @@
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <PackageId>MusicCatalogue.Logic</PackageId>
-    <PackageVersion>1.24.0.0</PackageVersion>
+    <PackageVersion>1.25.0.0</PackageVersion>
     <Authors>Dave Walker</Authors>
     <Copyright>Copyright (c) Dave Walker 2023</Copyright>
     <Owners>Dave Walker</Owners>
@@ -17,7 +17,7 @@
     <PackageProjectUrl>https://github.com/davewalker5/MusicCatalogue</PackageProjectUrl>
     <PackageLicenseExpression>MIT</PackageLicenseExpression>
     <PackageRequireLicenseAcceptance>false</PackageRequireLicenseAcceptance>
-    <ReleaseVersion>1.24.0.0</ReleaseVersion>
+    <ReleaseVersion>1.25.0.0</ReleaseVersion>
   </PropertyGroup>
 
   <ItemGroup>

src/MusicCatalogue.Tests/AlbumLookupManagerTest.cs

@@ -132,7 +132,7 @@ public void ArtistInDbButAlbumNotInDbTest()
         public void ArtistAndAlbumInDbTest()
         {
             var artistId = Task.Run(() => _factory!.Artists.AddAsync(ArtistName)).Result.Id;
-            var genreId = Task.Run(() => _factory!.Genres.AddAsync(Genre)).Result.Id;
+            var genreId = Task.Run(() => _factory!.Genres.AddAsync(Genre, false)).Result.Id;
             Task.Run(() => _factory!.Albums.AddAsync(artistId, genreId, AlbumTitle, Released, CoverUrl, false, null, null, null)).Wait();
             var album = Task.Run(() => _manager!.LookupAlbum(ArtistName, AlbumTitle, false)).Result;
 

src/MusicCatalogue.Tests/AlbumManagerTest.cs

@@ -33,7 +33,7 @@ public void TestInitialize()
 
             // Add the test entities to the database
             _retailerId = Task.Run(() => _factory.Retailers.AddAsync(RetailerName)).Result.Id;
-            _genreId = Task.Run(() => _factory.Genres.AddAsync(Genre)).Result.Id;
+            _genreId = Task.Run(() => _factory.Genres.AddAsync(Genre, false)).Result.Id;
             _artistId = Task.Run(() => _factory.Artists.AddAsync(ArtistName)).Result.Id;
             _albumId = Task.Run(() => _factory.Albums.AddAsync(_artistId, _genreId, AlbumTitle, Released, CoverUrl, false, null, null, null)).Result.Id;
             Task.Run(() => _factory.Tracks.AddAsync(_albumId, TrackTitle, TrackNumber, TrackDuration)).Wait();

src/MusicCatalogue.Tests/AlbumSearchManagerTest.cs

@@ -24,8 +24,8 @@ public void TestInitialize()
             _factory = new MusicCatalogueFactory(context);
 
             // Add the genres
-            _jazzGenreId = Task.Run(() => _factory.Genres.AddAsync("Jazz")).Result.Id;
-            _popGenreId = Task.Run(() => _factory.Genres.AddAsync("Pop")).Result.Id;
+            _jazzGenreId = Task.Run(() => _factory.Genres.AddAsync("Jazz", false)).Result.Id;
+            _popGenreId = Task.Run(() => _factory.Genres.AddAsync("Pop", false)).Result.Id;
 
             // Add the artists
             _jazzArtistId = Task.Run(() => _factory.Artists.AddAsync("Diana Krall")).Result.Id;

src/MusicCatalogue.Tests/ArtistManagerTest.cs

@@ -94,7 +94,7 @@ public async Task DeleteTest()
         [ExpectedException(typeof(ArtistInUseException))]
         public async Task CannotDeleteWithAlbumTest()
         {
-            var genreId = Task.Run(() => _factory!.Genres.AddAsync(Genre)).Result.Id;
+            var genreId = Task.Run(() => _factory!.Genres.AddAsync(Genre, false)).Result.Id;
             Task.Run(() => _factory!.Albums.AddAsync(_artistId, genreId, AlbumTitle, Released, null, false, null, null, null)).Wait();
             await _factory!.Artists.DeleteAsync(_artistId);
         }

src/MusicCatalogue.Tests/ArtistSearchManagerTest.cs

@@ -26,8 +26,8 @@ public void TestInitialize()
             _factory = new MusicCatalogueFactory(context);
 
             // Add the genres
-            _jazzGenreId = Task.Run(() => _factory.Genres.AddAsync("Jazz")).Result.Id;
-            _popGenreId = Task.Run(() => _factory.Genres.AddAsync("Pop")).Result.Id;
+            _jazzGenreId = Task.Run(() => _factory.Genres.AddAsync("Jazz", false)).Result.Id;
+            _popGenreId = Task.Run(() => _factory.Genres.AddAsync("Pop", false)).Result.Id;
 
             // Add the artists
             var jazzArtistId = Task.Run(() => _factory.Artists.AddAsync(JazzArtistName)).Result.Id;

src/MusicCatalogue.Tests/CatalogueDataExchangeTest.cs

@@ -33,7 +33,7 @@ public void Initialise()
             // Add an artist, an album and one track
             var retailer = Task.Run(() => _factory.Retailers.AddAsync(RetailerName)).Result;
             var artist = Task.Run(() => _factory.Artists.AddAsync(ArtistName)).Result;
-            var genre = Task.Run(() => _factory.Genres.AddAsync(Genre)).Result;
+            var genre = Task.Run(() => _factory.Genres.AddAsync(Genre, false)).Result;
             var album = Task.Run(() => _factory.Albums.AddAsync(artist.Id, genre.Id, AlbumName, Released, CoverUrl, false, Purchased, Price, retailer.Id)).Result;
             Task.Run(() => _factory.Tracks.AddAsync(album.Id, TrackName, TrackNumber, Duration)).Wait();
         }

src/MusicCatalogue.Tests/GenreManagerTest.cs

@@ -30,13 +30,21 @@ public void TestInitialize()
         {
             MusicCatalogueDbContext context = MusicCatalogueDbContextFactory.CreateInMemoryDbContext();
             _factory = new MusicCatalogueFactory(context);
-            _genreId = Task.Run(() => _factory.Genres.AddAsync(Genre)).Result.Id;
+            _genreId = Task.Run(() => _factory.Genres.AddAsync(Genre, false)).Result.Id;
         }
 
         [TestMethod]
-        public async Task AddDuplicateTest()
+        [ExpectedException(typeof(DuplicateGenreException))]
+        public async Task AddDuplicateWithErrorTest()
         {
-            await _factory!.Genres.AddAsync(Genre);
+            await _factory!.Genres.AddAsync(Genre, true);
+        }
+
+        [TestMethod]
+
+        public async Task AddDuplicateWithNoErrorTest()
+        {
+            await _factory!.Genres.AddAsync(Genre, false);
             var genres = await _factory!.Genres.ListAsync(x => true);
             Assert.AreEqual(1, genres.Count);
         }
@@ -82,10 +90,10 @@ public async Task UpdateTest()
         }
 
         [TestMethod]
+        [ExpectedException(typeof(GenreNotFoundException))]
         public async Task UpdateMissingTest()
         {
-            var genre = await _factory!.Genres.UpdateAsync(-1, UpdatedGenre);
-            Assert.IsNull(genre);
+            _ = await _factory!.Genres.UpdateAsync(-1, UpdatedGenre);
         }
 
         [TestMethod]

src/MusicCatalogue.Tests/GenreSearchManagerTest.cs

@@ -24,8 +24,8 @@ public void TestInitialize()
             _factory = new MusicCatalogueFactory(context);
 
             // Add the genres
-            _jazzGenreId = Task.Run(() => _factory.Genres.AddAsync("Jazz")).Result.Id;
-            _popGenreId = Task.Run(() => _factory.Genres.AddAsync("Pop")).Result.Id;
+            _jazzGenreId = Task.Run(() => _factory.Genres.AddAsync("Jazz", false)).Result.Id;
+            _popGenreId = Task.Run(() => _factory.Genres.AddAsync("Pop", false)).Result.Id;
 
             // Add the artists
             _jazzArtistId = Task.Run(() => _factory.Artists.AddAsync("Diana Krall")).Result.Id;

src/MusicCatalogue.Tests/RetailerManagerTest.cs

@@ -106,7 +106,7 @@ public async Task DeleteInUseTest()
         {
             // Add an album that uses the retailer
             var artist = await _factory!.Artists.AddAsync(ArtistName);
-            var genre = await _factory.Genres.AddAsync(Genre);
+            var genre = await _factory.Genres.AddAsync(Genre, false);
             await _factory.Albums.AddAsync(artist.Id, genre.Id, AlbumTitle, Released, CoverUrl, false, null, null, _retailerId);
 
             // Now try to delete the retailer - this should raise an exception

src/MusicCatalogue.Tests/TrackManagerTest.cs

@@ -33,7 +33,7 @@ public void TestInitialize()
 
             // Set up an artist and album for the tracks to belong to
             _artistId = Task.Run(() => factory.Artists.AddAsync(ArtistName)).Result.Id;
-            var genreId = Task.Run(() => factory.Genres.AddAsync(Genre)).Result.Id;
+            var genreId = Task.Run(() => factory.Genres.AddAsync(Genre, false)).Result.Id;
             _albumId = Task.Run(() => factory.Albums.AddAsync(_artistId, genreId, AlbumTitle, Released, CoverUrl, false, null, null, null)).Result.Id;
 
             // Create a track manager and add a test track