Add tests

BudgetApp.Tests/Services/CategoryServiceTests.cs

@@ -0,0 +1,275 @@
+using BudgetApp.Data;
+using BudgetApp.Services;
+using BudgetApp.Tests.Helpers;
+using Microsoft.EntityFrameworkCore;
+using Xunit;
+
+namespace BudgetApp.Tests.Services;
+
+public class CategoryServiceTests
+{
+    [Fact]
+    public async Task GetCategoriesAsync_ReturnsOnlyUserCategories()
+    {
+        using var factory = new TestDbContextFactory();
+        using (var ctx = factory.CreateContext())
+        {
+            ctx.Categories.AddRange(
+                new Category { Name = "Mine", UserId = TestDbContextFactory.TestUserId },
+                new Category { Name = "Theirs", UserId = TestDbContextFactory.OtherUserId });
+            await ctx.SaveChangesAsync();
+        }
+
+        using var context = factory.CreateContext();
+        var service = new CategoryService(context);
+
+        var result = await service.GetCategoriesAsync(TestDbContextFactory.TestUserId);
+
+        Assert.Single(result);
+        Assert.Equal("Mine", result[0].Name);
+    }
+
+    [Fact]
+    public async Task GetCategoriesAsync_OrderedByName()
+    {
+        using var factory = new TestDbContextFactory();
+        using (var ctx = factory.CreateContext())
+        {
+            ctx.Categories.AddRange(
+                new Category { Name = "Zebra", UserId = TestDbContextFactory.TestUserId },
+                new Category { Name = "Alpha", UserId = TestDbContextFactory.TestUserId });
+            await ctx.SaveChangesAsync();
+        }
+
+        using var context = factory.CreateContext();
+        var service = new CategoryService(context);
+
+        var result = await service.GetCategoriesAsync(TestDbContextFactory.TestUserId);
+
+        Assert.Equal("Alpha", result[0].Name);
+        Assert.Equal("Zebra", result[1].Name);
+    }
+
+    [Fact]
+    public async Task EnsureDefaultCategoriesAsync_CreatesDefaults_WhenEmpty()
+    {
+        using var factory = new TestDbContextFactory();
+        using var context = factory.CreateContext();
+        var service = new CategoryService(context);
+
+        await service.EnsureDefaultCategoriesAsync(TestDbContextFactory.TestUserId);
+
+        using var verifyCtx = factory.CreateContext();
+        var categories = await verifyCtx.Categories
+            .Where(c => c.UserId == TestDbContextFactory.TestUserId)
+            .ToListAsync();
+
+        Assert.Equal(15, categories.Count);
+        Assert.Contains(categories, c => c.Name == "Groceries" && c.Icon == "🛒");
+        Assert.Contains(categories, c => c.Name == "Transport" && c.Icon == "🚗");
+        Assert.Contains(categories, c => c.Name == "Salary" && c.Icon == "💰");
+    }
+
+    [Fact]
+    public async Task EnsureDefaultCategoriesAsync_DoesNotDuplicate_WhenCalledAgain()
+    {
+        using var factory = new TestDbContextFactory();
+
+        using (var ctx = factory.CreateContext())
+        {
+            var service = new CategoryService(ctx);
+            await service.EnsureDefaultCategoriesAsync(TestDbContextFactory.TestUserId);
+        }
+
+        using (var ctx = factory.CreateContext())
+        {
+            var service = new CategoryService(ctx);
+            await service.EnsureDefaultCategoriesAsync(TestDbContextFactory.TestUserId);
+        }
+
+        using var verifyCtx = factory.CreateContext();
+        var count = await verifyCtx.Categories
+            .Where(c => c.UserId == TestDbContextFactory.TestUserId)
+            .CountAsync();
+
+        Assert.Equal(15, count);
+    }
+
+    [Fact]
+    public async Task EnsureDefaultCategoriesAsync_BackfillsIcons_WhenMissing()
+    {
+        using var factory = new TestDbContextFactory();
+        using (var ctx = factory.CreateContext())
+        {
+            ctx.Categories.Add(new Category
+            {
+                Name = "Groceries",
+                Icon = "",
+                UserId = TestDbContextFactory.TestUserId
+            });
+            await ctx.SaveChangesAsync();
+        }
+
+        using var context = factory.CreateContext();
+        var service = new CategoryService(context);
+        await service.EnsureDefaultCategoriesAsync(TestDbContextFactory.TestUserId);
+
+        using var verifyCtx = factory.CreateContext();
+        var category = await verifyCtx.Categories
+            .SingleAsync(c => c.Name == "Groceries" && c.UserId == TestDbContextFactory.TestUserId);
+
+        Assert.Equal("🛒", category.Icon);
+    }
+
+    [Fact]
+    public async Task EnsureDefaultCategoriesAsync_DoesNotOverwrite_ExistingIcons()
+    {
+        using var factory = new TestDbContextFactory();
+        using (var ctx = factory.CreateContext())
+        {
+            ctx.Categories.Add(new Category
+            {
+                Name = "Groceries",
+                Icon = "🥕",
+                UserId = TestDbContextFactory.TestUserId
+            });
+            await ctx.SaveChangesAsync();
+        }
+
+        using var context = factory.CreateContext();
+        var service = new CategoryService(context);
+        await service.EnsureDefaultCategoriesAsync(TestDbContextFactory.TestUserId);
+
+        using var verifyCtx = factory.CreateContext();
+        var category = await verifyCtx.Categories
+            .SingleAsync(c => c.Name == "Groceries" && c.UserId == TestDbContextFactory.TestUserId);
+
+        Assert.Equal("🥕", category.Icon);
+    }
+
+    [Fact]
+    public async Task EnsureDefaultCategoriesAsync_IsolatedPerUser()
+    {
+        using var factory = new TestDbContextFactory();
+
+        using (var ctx = factory.CreateContext())
+        {
+            var service = new CategoryService(ctx);
+            await service.EnsureDefaultCategoriesAsync(TestDbContextFactory.TestUserId);
+        }
+
+        using (var ctx = factory.CreateContext())
+        {
+            var service = new CategoryService(ctx);
+            await service.EnsureDefaultCategoriesAsync(TestDbContextFactory.OtherUserId);
+        }
+
+        using var verifyCtx = factory.CreateContext();
+        var totalCount = await verifyCtx.Categories.CountAsync();
+        Assert.Equal(30, totalCount);
+    }
+
+    [Fact]
+    public async Task CreateCategoryAsync_AddsToDatabase()
+    {
+        using var factory = new TestDbContextFactory();
+        using var context = factory.CreateContext();
+        var service = new CategoryService(context);
+
+        await service.CreateCategoryAsync(new Category
+        {
+            Name = "Custom",
+            Icon = "🎯",
+            UserId = TestDbContextFactory.TestUserId
+        });
+
+        using var verifyCtx = factory.CreateContext();
+        Assert.Single(verifyCtx.Categories);
+    }
+
+    [Fact]
+    public async Task UpdateCategoryAsync_UpdatesNameAndIcon()
+    {
+        using var factory = new TestDbContextFactory();
+        int categoryId;
+        using (var ctx = factory.CreateContext())
+        {
+            var category = new Category { Name = "Old", Icon = "📁", UserId = TestDbContextFactory.TestUserId };
+            ctx.Categories.Add(category);
+            await ctx.SaveChangesAsync();
+            categoryId = category.Id;
+        }
+
+        using var context = factory.CreateContext();
+        var service = new CategoryService(context);
+        await service.UpdateCategoryAsync(categoryId, TestDbContextFactory.TestUserId, "New", "🎯");
+
+        using var verifyCtx = factory.CreateContext();
+        var updated = verifyCtx.Categories.Single();
+        Assert.Equal("New", updated.Name);
+        Assert.Equal("🎯", updated.Icon);
+    }
+
+    [Fact]
+    public async Task UpdateCategoryAsync_WrongUser_DoesNothing()
+    {
+        using var factory = new TestDbContextFactory();
+        int categoryId;
+        using (var ctx = factory.CreateContext())
+        {
+            var category = new Category { Name = "Original", Icon = "📁", UserId = TestDbContextFactory.TestUserId };
+            ctx.Categories.Add(category);
+            await ctx.SaveChangesAsync();
+            categoryId = category.Id;
+        }
+
+        using var context = factory.CreateContext();
+        var service = new CategoryService(context);
+        await service.UpdateCategoryAsync(categoryId, TestDbContextFactory.OtherUserId, "Hacked", "💀");
+
+        using var verifyCtx = factory.CreateContext();
+        Assert.Equal("Original", verifyCtx.Categories.Single().Name);
+    }
+
+    [Fact]
+    public async Task DeleteCategoryAsync_RemovesCategory()
+    {
+        using var factory = new TestDbContextFactory();
+        int categoryId;
+        using (var ctx = factory.CreateContext())
+        {
+            var category = new Category { Name = "ToDelete", UserId = TestDbContextFactory.TestUserId };
+            ctx.Categories.Add(category);
+            await ctx.SaveChangesAsync();
+            categoryId = category.Id;
+        }
+
+        using var context = factory.CreateContext();
+        var service = new CategoryService(context);
+        await service.DeleteCategoryAsync(categoryId, TestDbContextFactory.TestUserId);
+
+        using var verifyCtx = factory.CreateContext();
+        Assert.Empty(verifyCtx.Categories);
+    }
+
+    [Fact]
+    public async Task DeleteCategoryAsync_WrongUser_DoesNothing()
+    {
+        using var factory = new TestDbContextFactory();
+        int categoryId;
+        using (var ctx = factory.CreateContext())
+        {
+            var category = new Category { Name = "Protected", UserId = TestDbContextFactory.TestUserId };
+            ctx.Categories.Add(category);
+            await ctx.SaveChangesAsync();
+            categoryId = category.Id;
+        }
+
+        using var context = factory.CreateContext();
+        var service = new CategoryService(context);
+        await service.DeleteCategoryAsync(categoryId, TestDbContextFactory.OtherUserId);
+
+        using var verifyCtx = factory.CreateContext();
+        Assert.Single(verifyCtx.Categories);
+    }
+}