Add GetTagsQueryHandlerTests tests

src/Blogger.Application/Articles/GetTags/GetTagsQuery.cs

@@ -1,3 +1,3 @@
 namespace Blogger.Application.Articles.GetTags;
 public record GetTagsQuery()
-    : IRequest<IReadOnlyList<GetTagsQueryResponse>>;
+    : IRequest<IReadOnlyCollection<GetTagsQueryResponse>>;

src/Blogger.Application/Articles/GetTags/GetTagsQueryHandler.cs

@@ -1,16 +1,14 @@
 namespace Blogger.Application.Articles.GetTags;
 
 public class GetTagsQueryHandler(IArticleRepository articleRepository)
-    : IRequestHandler<GetTagsQuery, IReadOnlyList<GetTagsQueryResponse>>
+    : IRequestHandler<GetTagsQuery, IReadOnlyCollection<GetTagsQueryResponse>>
 {
     private readonly IArticleRepository _articleRepository = articleRepository;
 
-    public async Task<IReadOnlyList<GetTagsQueryResponse>> Handle(GetTagsQuery request, CancellationToken cancellationToken)
+    public async Task<IReadOnlyCollection<GetTagsQueryResponse>> Handle(GetTagsQuery request, CancellationToken cancellationToken)
     {
         var tags = await _articleRepository.GetTagsAsync(cancellationToken);
 
-        return tags.GroupBy(x => x)
-                   .Select(x => new GetTagsQueryResponse(x.Key, x.Count()))
-                   .ToImmutableList();
+        return [.. tags.Select(x => new GetTagsQueryResponse(x.Tag, x.Count))];
     }
 }

src/Blogger.Domain/ArticleAggregate/IArticleRepository.cs

@@ -20,8 +20,8 @@ public interface IArticleRepository
 
     Task<IReadOnlyCollection<Article>> GetLatestArticlesAsync(Tag tag, CancellationToken cancellationToken);
 
+    Task<IReadOnlyCollection<TagModel>> GetTagsAsync(CancellationToken cancellationToken);
 
-    Task<IReadOnlyList<Tag>> GetTagsAsync(CancellationToken cancellationToken);
     Task SaveChangesAsync(CancellationToken cancellationToken);
     void Delete(Article draft);
     Task<Article?> GetDraftByIdAsync(ArticleId draftId, CancellationToken cancellationToken);

src/Blogger.Domain/ArticleAggregate/Models/TagModel.cs

@@ -0,0 +1,2 @@
+namespace Blogger.Domain.ArticleAggregate.Models;
+public sealed record TagModel(Tag Tag, int Count);

src/Blogger.Infrastructure/Persistence/Repositories/ArticleRepository.cs

@@ -83,19 +83,18 @@ public async Task<IReadOnlyCollection<Article>> GetLatestArticlesAsync(Tag tag,
 
         return [.. articles];
     }
-
-
-
-
-    public async Task<IReadOnlyList<Tag>> GetTagsAsync(CancellationToken cancellationToken)
+
+    public async Task<IReadOnlyCollection<TagModel>> GetTagsAsync(CancellationToken cancellationToken)
     {
         var tags = await bloggerDbContext.Articles
                                          .AsNoTracking()
                                          .Where(x => x.Status == ArticleStatus.Published)
                                          .SelectMany(x => x.Tags)
+                                         .GroupBy(x => x.Value)
+                                         .Select(x => new TagModel(Tag.Create(x.Key), x.Count()))
                                          .ToListAsync(cancellationToken);
 
-        return tags.ToImmutableList();
+        return[.. tags];
     }
 
 

tests/Blogger.IntegrationTests/Articles/GetTagsQueryHandlerTests.cs

@@ -0,0 +1,69 @@
+using System.Collections.Immutable;
+using Blogger.Application.Articles.GetTags;
+using Blogger.Domain.ArticleAggregate;
+using Blogger.Infrastructure.Persistence.Repositories;
+using Blogger.IntegrationTests.Fixtures;
+
+using FluentAssertions;
+
+namespace Blogger.IntegrationTests.Articles;
+public class GetTagsQueryHandlerTests : IClassFixture<BloggerDbContextFixture>
+{
+    private readonly BloggerDbContextFixture _fixture;
+
+    public GetTagsQueryHandlerTests(BloggerDbContextFixture fixture)
+    {
+        _fixture = fixture;
+    }
+
+    [Fact]
+    public async Task Handle_ShouldReturnTags_WhenTagsExist()
+    {
+        // Arrange
+        var articleRepository = new ArticleRepository(_fixture.BuildDbContext(Guid.NewGuid().ToString()));
+        var sut = new GetTagsQueryHandler(articleRepository);
+
+        var article_1 = Article.CreateArticle("Title 1", "Test Body", "Test Summary", [Tag.Create("tag1"), Tag.Create("tag3")]);
+        var article_2 = Article.CreateArticle("Title 2", "Test Body", "Test Summary", [Tag.Create("tag1"), Tag.Create("tag4")]);
+
+        articleRepository.Add(article_1);
+        articleRepository.Add(article_2);
+
+        await articleRepository.SaveChangesAsync(CancellationToken.None);
+
+        var request = new GetTagsQuery();
+
+        // Act
+        var response = (await sut.Handle(request, CancellationToken.None)).ToImmutableList();
+
+        // Assert
+        response.Should().NotBeNull();
+        response.Should().HaveCount(3);
+
+        response[0].Tag.Value.Should().Be("tag1");
+        response[0].Count.Should().Be(2);
+
+        response[1].Tag.Value.Should().Be("tag3");
+        response[1].Count.Should().Be(1);
+
+        response[2].Tag.Value.Should().Be("tag4");
+        response[2].Count.Should().Be(1);
+    }
+
+    [Fact]
+    public async Task Handle_ShouldReturnEmpty_WhenNoTagsExist()
+    {
+        // Arrange
+        var articleRepository = new ArticleRepository(_fixture.BuildDbContext(Guid.NewGuid().ToString()));
+        var sut = new GetTagsQueryHandler(articleRepository);
+
+        var request = new GetTagsQuery();
+
+        // Act
+        var response = await sut.Handle(request, CancellationToken.None);
+
+        // Assert
+        response.Should().NotBeNull();
+        response.Should().BeEmpty();
+    }
+}