SetItemAsStringAsync.cs

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

namespace Blazored.SessionStorage.Tests.SessionStorageServiceTests;

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

    private const string Key = "testKey";

    public SetItemAsStringAsync()
    {
        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
        const string data = "Data";
        var action = new Func<Task>(async () => await _sut.SetItemAsStringAsync(key, data));

        // assert
        Assert.ThrowsAsync<ArgumentNullException>(action);
    }
        
    [Fact]
    public void ThrowsArgumentNullException_When_DataIsNull()
    {
        // arrange / act
        var data = (string)null;
        var action = new Func<Task>(async () => await _sut.SetItemAsStringAsync("MyValue", data));

        // assert
        Assert.ThrowsAsync<ArgumentNullException>(action);
    }

    [Fact]
    public async Task RaisesOnChangingEvent_When_SavingNewData()
    {
        // arrange
        var onChangingCalled = false;
        _sut.Changing += (_, _) => onChangingCalled = true;

        // act
        await _sut.SetItemAsStringAsync("Key", "Data");

        // assert
        Assert.True(onChangingCalled);
    }
        
    [Fact]
    public async Task OnChangingEventContainsEmptyOldValue_When_SavingData()
    {
        // arrange
        var oldValue = "";
        _sut.Changing += (_, args) => oldValue = args.OldValue?.ToString();

        // act
        await _sut.SetItemAsStringAsync("Key", "Data");

        // assert
        Assert.Equal(default, oldValue);
    }
        
    [Fact]
    public async Task OnChangingEventContainsNewValue_When_SavingNewData()
    {
        // arrange
        const string data = "Data";
        var newValue = "";
        _sut.Changing += (_, args) => newValue = args.NewValue.ToString();

        // act
        await _sut.SetItemAsStringAsync("Key", data);

        // assert
        Assert.Equal(data, newValue);
    }
        
    [Fact]
    public async Task OnChangingEventIsCancelled_When_SettingCancelToTrue_When_SavingNewData()
    {
        // arrange
        _sut.Changing += (_, args) => args.Cancel = true;

        // act
        await _sut.SetItemAsStringAsync("Key", "Data");

        // assert
        Assert.Equal(0, _storageProvider.Length());
    }
        
    [Fact]
    public async Task SavesDataToStore()
    {
        // Act
        var valueToSave = "StringValue";
        await _sut.SetItemAsStringAsync(Key, valueToSave);

        // Assert
        var valueFromStore = _storageProvider.GetItem(Key);

        Assert.Equal(1, _storageProvider.Length());
        Assert.Equal(valueToSave, valueFromStore);
    }
        
    [Fact]
    public async Task OverwriteExistingValueInStore_When_UsingTheSameKey()
    {
        // Arrange
        const string existingValue = "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJodHRwOi8vc2NoZW1hcy54bWxzb2FwLm9yZy93cy8yMDA1LzA1L2lkZW50aXR5L2NsYWltcy9uYW1lIjoiYWRtaW4iLCJodHRwOi8vc2NoZW1hcy5taWNyb3NvZnQuY29tL3dzLzIwMDgvMDYvaWRlbnRpdHkvY2xhaW1zL3JvbGUiOiJBZG1pbmlzdHJhdG9yIiwiZXhwIjoxNTg1NjYwNzEyLCJpc3MiOiJDb2RlUmVkQm9va2luZy5TZXJ2ZXIiLCJhdWQiOiJDb2RlUmVkQm9va2luZy5DbGllbnRzIn0.JhK1M1H7NLCFexujJYCDjTn9La0HloGYADMHXGCFksU";
        const string newValue = "6QLE0LL7iw7tHPAwold31qUENt3lVTUZxDGqeXQFx38=";

        _storageProvider.SetItem(Key, existingValue);

        // Act
        await _sut.SetItemAsStringAsync(Key, newValue);

        // Assert
        var updatedValue = _storageProvider.GetItem(Key);

        Assert.Equal(newValue, updatedValue);
    }
        
    [Fact]
    public async Task RaisesOnChangedEvent_When_SavingData()
    {
        // arrange
        var onChangedCalled = false;
        _sut.Changed += (_, _) => onChangedCalled = true;

        // act
        await _sut.SetItemAsStringAsync("Key", "Data");

        // assert
        Assert.True(onChangedCalled);
    }
        
    [Fact]
    public async Task OnChangedEventContainsEmptyOldValue_When_SavingNewData()
    {
        // arrange
        var oldValue = "";
        _sut.Changed += (_, args) => oldValue = args.OldValue?.ToString();

        // act
        await _sut.SetItemAsStringAsync("Key", "Data");

        // assert
        Assert.Equal(default, oldValue);
    }
        
    [Fact]
    public async Task OnChangedEventContainsNewValue_When_SavingNewData()
    {
        // arrange
        const string data = "Data";
        var newValue = "";
        _sut.Changed += (_, args) => newValue = args.NewValue.ToString();

        // act
        await _sut.SetItemAsStringAsync("Key", data);

        // assert
        Assert.Equal(data, newValue);
    }
        
    [Fact]
    public async Task OnChangedEventContainsOldValue_When_UpdatingExistingData()
    {
        // arrange
        var existingValue = "Foo";
        _storageProvider.SetItem("Key", existingValue);
        var oldValue = "";
        _sut.Changed += (_, args) => oldValue = args.OldValue?.ToString();

        // act
        await _sut.SetItemAsStringAsync("Key", "Data");

        // assert
        Assert.Equal(existingValue, oldValue);
    }
}