Add unit tests for LocalStorageService: implement tests for GetItem, SetItem, and RemoveItem methods

FoodsharingSiegen.Tests/LocalStorageServiceTests.cs

@@ -0,0 +1,87 @@
+using System.Text.Json;
+using FoodsharingSiegen.Server.Service;
+using Microsoft.JSInterop;
+using Moq;
+using Xunit;
+
+namespace FoodsharingSiegen.Tests
+{
+    public class LocalStorageServiceTests
+    {
+        [Fact]
+        public async Task GetItem_ReturnsDeserializedObject_WhenItemExists()
+        {
+            // Arrange
+            var mockJsRuntime = new Mock<IJSRuntime>();
+            var service = new LocalStorageService(mockJsRuntime.Object);
+            var expectedObject = new { Name = "Test" };
+            var jsonString = JsonSerializer.Serialize(expectedObject);
+
+            mockJsRuntime.Setup(x => x.InvokeAsync<string>("localStorage.getItem", It.IsAny<object[]>()))
+                         .ReturnsAsync(jsonString);
+
+            // Act
+            var result = await service.GetItem<dynamic>("testKey");
+
+            // Assert
+            Assert.NotNull(result);
+            mockJsRuntime.Verify(x => x.InvokeAsync<string>("localStorage.getItem", It.Is<object[]>(args => args.Length == 1 && args[0].ToString() == "testKey")), Times.Once);
+        }
+
+        [Fact]
+        public async Task GetItem_ReturnsDefault_WhenItemDoesNotExist()
+        {
+            // Arrange
+            var mockJsRuntime = new Mock<IJSRuntime>();
+            var service = new LocalStorageService(mockJsRuntime.Object);
+
+            mockJsRuntime.Setup(x => x.InvokeAsync<string>("localStorage.getItem", It.IsAny<object[]>()))
+                         .ReturnsAsync((string?)null);
+
+            // Act
+            var result = await service.GetItem<string>("testKey");
+
+            // Assert
+            Assert.Null(result);
+        }
+
+        [Fact]
+        public async Task SetItem_CallsSetItemInLocalStorage()
+        {
+            // Arrange
+            var mockJsRuntime = new Mock<IJSRuntime>();
+            var service = new LocalStorageService(mockJsRuntime.Object);
+            var objectToSave = new { Name = "Test" };
+            var expectedJson = JsonSerializer.Serialize(objectToSave);
+
+            // Act
+            await service.SetItem("testKey", objectToSave);
+
+            // Assert
+            // Note: InvokeVoidAsync is an extension method that calls InvokeAsync<IJSVoidResult> under the hood in Blazor.
+            mockJsRuntime.Verify(
+                x => x.InvokeAsync<It.IsAnyType>(
+                    "localStorage.setItem", 
+                    It.Is<object[]>(args => args.Length == 2 && args[0].ToString() == "testKey" && args[1].ToString() == expectedJson)),
+                Times.Once);
+        }
+
+        [Fact]
+        public async Task RemoveItem_CallsRemoveItemInLocalStorage()
+        {
+            // Arrange
+            var mockJsRuntime = new Mock<IJSRuntime>();
+            var service = new LocalStorageService(mockJsRuntime.Object);
+
+            // Act
+            await service.RemoveItem("testKey");
+
+            // Assert
+            mockJsRuntime.Verify(
+                x => x.InvokeAsync<It.IsAnyType>(
+                    "localStorage.removeItem", 
+                    It.Is<object[]>(args => args.Length == 1 && args[0].ToString() == "testKey")),
+                Times.Once);
+        }
+    }
+}