Add LoadableViewModel tests

StabilityMatrix.Tests/Avalonia/LoadableViewModelBaseTests.cs

@@ -0,0 +1,203 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using Moq;
+using StabilityMatrix.Avalonia.Models;
+using StabilityMatrix.Avalonia.ViewModels;
+#pragma warning disable CS0657 // Not a valid attribute location for this declaration
+
+namespace StabilityMatrix.Tests.Avalonia;
+
+// Example subclass
+public class TestLoadableViewModel : LoadableViewModelBase
+{
+    [JsonInclude]
+    public string? Included { get; set; }
+    
+    public int Id { get; set; }
+    
+    [JsonIgnore]
+    public int Ignored { get; set; }
+}
+
+public partial class TestLoadableViewModelObservable : LoadableViewModelBase
+{
+    [ObservableProperty]
+    [property: JsonIgnore]
+    private string? title;
+    
+    [ObservableProperty]
+    private int id;
+    
+    [RelayCommand]
+    private void TestCommand()
+    {
+        throw new NotImplementedException();
+    }
+}
+
+public class TestLoadableViewModelNestedInterface : LoadableViewModelBase
+{
+    public IJsonLoadableState? NestedState { get; set; }
+}
+
+public class TestLoadableViewModelNested : LoadableViewModelBase
+{
+    public TestLoadableViewModel? NestedState { get; set; }
+}
+
+[TestClass]
+public class LoadableViewModelBaseTests
+{
+    [TestMethod]
+    public void TestSaveStateToJsonObject_JsonIgnoreAttribute()
+    {
+        var vm = new TestLoadableViewModel
+        {
+            Included = "abc",
+            Id = 123,
+            Ignored = 456,
+        };
+        
+        var state = vm.SaveStateToJsonObject();
+        
+        // [JsonInclude] and not marked property should be serialized.
+        // Ignored property should be ignored.
+        Assert.AreEqual(2, state.Count);
+        Assert.AreEqual("abc", state["Included"].Deserialize<string>());
+        Assert.AreEqual(123, state["Id"].Deserialize<int>());
+    }
+
+    [TestMethod]
+    public void TestSaveStateToJsonObject_Observable()
+    {
+        // Mvvm ObservableProperty should be serialized.
+        var vm = new TestLoadableViewModelObservable
+        {
+            Title = "abc",
+            Id = 123,
+        };
+        var state = vm.SaveStateToJsonObject();
+        
+        // Title should be ignored since it has [JsonIgnore]
+        // Command should be ignored from excluded type rules
+        // Id should be serialized
+        
+        Assert.AreEqual(1, state.Count);
+        Assert.AreEqual(123, state["Id"].Deserialize<int>());
+    }
+
+    [TestMethod]
+    public void TestSaveStateToJsonObject_IJsonLoadableState()
+    {
+        // Properties of type IJsonLoadableState should be serialized by calling their
+        // SaveStateToJsonObject method.
+        
+        // Make a mock IJsonLoadableState
+        var mockState = new Mock<IJsonLoadableState>();
+
+        var vm = new TestLoadableViewModelNestedInterface
+        {
+            NestedState = mockState.Object
+        };
+        
+        // Serialize
+        var state = vm.SaveStateToJsonObject();
+        
+        // Check results
+        Assert.AreEqual(1, state.Count);
+        
+        // Check that SaveStateToJsonObject was called
+        mockState.Verify(x => x.SaveStateToJsonObject(), Times.Once);
+    }
+
+    [TestMethod]
+    public void TestLoadStateFromJsonObject()
+    {
+        // Simple round trip save / load
+        var vm = new TestLoadableViewModel
+        {
+            Included = "abc",
+            Id = 123,
+            Ignored = 456,
+        };
+        
+        var state = vm.SaveStateToJsonObject();
+        
+        // Create a new instance and load the state
+        var vm2 = new TestLoadableViewModel();
+        vm2.LoadStateFromJsonObject(state);
+        
+        // Check [JsonInclude] and not marked property was loaded
+        Assert.AreEqual("abc", vm2.Included);
+        Assert.AreEqual(123, vm2.Id);
+        // Check ignored property was not loaded
+        Assert.AreEqual(0, vm2.Ignored);
+    }
+    
+    [TestMethod]
+    public void TestLoadStateFromJsonObject_Nested_DefaultCtor()
+    {
+        // Round trip save / load with nested IJsonLoadableState property
+        var nested = new TestLoadableViewModel
+        {
+            Included = "abc",
+            Id = 123,
+            Ignored = 456,
+        };
+        
+        var vm = new TestLoadableViewModelNested
+        {
+            NestedState = nested
+        };
+        
+        var state = vm.SaveStateToJsonObject();
+        
+        // Create a new instance with null NestedState, rely on default ctor
+        var vm2 = new TestLoadableViewModelNested();
+        vm2.LoadStateFromJsonObject(state);
+        
+        // Check nested state was loaded
+        Assert.IsNotNull(vm2.NestedState);
+        
+        var loadedNested = (TestLoadableViewModel) vm2.NestedState;
+        Assert.AreEqual("abc", loadedNested.Included);
+        Assert.AreEqual(123, loadedNested.Id);
+        Assert.AreEqual(0, loadedNested.Ignored);
+    }
+    
+    [TestMethod]
+    public void TestLoadStateFromJsonObject_Nested_Existing()
+    {
+        // Round trip save / load with nested IJsonLoadableState property
+        var nested = new TestLoadableViewModel
+        {
+            Included = "abc",
+            Id = 123,
+            Ignored = 456,
+        };
+        
+        var vm = new TestLoadableViewModelNestedInterface
+        {
+            NestedState = nested
+        };
+        
+        var state = vm.SaveStateToJsonObject();
+        
+        // Create a new instance with existing NestedState
+        var vm2 = new TestLoadableViewModelNestedInterface
+        {
+            NestedState = new TestLoadableViewModel()
+        };
+        vm2.LoadStateFromJsonObject(state);
+        
+        // Check nested state was loaded
+        Assert.IsNotNull(vm2.NestedState);
+        
+        var loadedNested = (TestLoadableViewModel) vm2.NestedState;
+        Assert.AreEqual("abc", loadedNested.Included);
+        Assert.AreEqual(123, loadedNested.Id);
+        Assert.AreEqual(0, loadedNested.Ignored);
+    }
+}