GetItem.cs

using System;
using System.Text.Json;
using Blazored.SessionStorage.JsonConverters;
using Blazored.SessionStorage.Serialization;
using Blazored.SessionStorage.StorageOptions;
using Blazored.SessionStorage.TestExtensions;
using Blazored.SessionStorage.Tests.TestAssets;
using Microsoft.Extensions.Options;
using Moq;
using Xunit;

namespace Blazored.SessionStorage.Tests.SessionStorageServiceTests;

public class GetItem
{
    private readonly SessionStorageService _sut;
    private readonly IStorageProvider _storageProvider;
    private readonly IJsonSerializer _serializer;

    private const string Key = "testKey";

    public GetItem()
    {
        var mockOptions = new Mock<IOptions<SessionStorageOptions>>();
        var jsonOptions = new JsonSerializerOptions();
        jsonOptions.Converters.Add(new TimespanJsonConverter());
        mockOptions.Setup(u => u.Value).Returns(new SessionStorageOptions());
        _serializer = new SystemTextJsonSerializer(mockOptions.Object);
        _storageProvider = new InMemoryStorageProvider();
        _sut = new SessionStorageService(_storageProvider, _serializer);
    }

    [Theory]
    [InlineData("")]
    [InlineData("  ")]
    [InlineData(null)]
    public void ThrowsArgumentNullException_When_KeyIsInvalid(string key)
    {
        // arrange / act
        var action = new Action(() => _sut.GetItem<object>(key));

        // assert
        Assert.Throws<ArgumentNullException>(action);
    }
        
    [Theory]
    [InlineData("Item1", "stringTest")]
    [InlineData("Item2", 11)]
    [InlineData("Item3", 11.11)]
    public void ReturnsDeserializedDataFromStore<T>(string key, T data)
    {
        // Arrange
        _sut.SetItem(key, data);
            
        // Act
        var result = _sut.GetItem<T>(key);

        // Assert
        Assert.Equal(data, result);
    }

    [Fact]
    public void ReturnsComplexObjectFromStore()
    {
        // Arrange
        var objectToSave = new TestObject(2, "Jane Smith");
        _sut.SetItem(Key, objectToSave);

        // Act
        var result = _sut.GetItem<TestObject>(Key);

        // Assert
        Assert.Equal(objectToSave.Id, result.Id);
        Assert.Equal(objectToSave.Name, result.Name);
    }
        
    [Fact]
    public void ReturnsNullFromStore_When_NullValueSaved()
    {
        // Arrange
        var valueToSave = (string)null;
        _sut.SetItem(Key, valueToSave);

        // Act
        var result = _sut.GetItem<string>(Key);

        // Assert
        Assert.Null(result);
    }
        
    [Fact]
    public void ReturnsStringFromStore_When_JsonExceptionIsThrown()
    {
        // Arrange
        var jsonData = "[{ id: 5, name: \"Jane Smith\"}]";
        _storageProvider.SetItem(Key, jsonData);

        // Act
        var result = _sut.GetItem<string>(Key);

        // Assert
        Assert.Equal(jsonData, result);
    }
}