LehrerApp/LehrerApp.Desktop.Tests/StudentPickerDialogViewModelTests.cs

using LehrerApp.Core.Models;
using LehrerApp.Desktop.ViewModels.Students;
using Xunit;

namespace LehrerApp.Desktop.Tests;

public sealed class StudentPickerDialogViewModelTests
{
    private static (StudentPickerDialogViewModel Vm, Student Anna, Student Ben) Build()
    {
        var anna = new Student { FirstName = "Anna", LastName = "Adler" };
        var ben = new Student { FirstName = "Ben", LastName = "Bauer" };
        var vm = new StudentPickerDialogViewModel(new FakeStudents([anna, ben]));
        return (vm, anna, ben);
    }

    [Fact]
    public void SearchText_FiltertNachTeilstring()
    {
        var (vm, anna, _) = Build();

        vm.SearchText = "ann";

        Assert.Single(vm.Students);
        Assert.Equal(anna.FullName, vm.Students[0].FullName);
    }

    [Fact]
    public void Select_OhneAuswahl_SetztValidationMessage()
    {
        var (vm, _, _) = Build();

        vm.SelectCommand.Execute(null);

        Assert.Null(vm.Result);
        Assert.NotEqual("", vm.ValidationMessage);
    }

    [Fact]
    public void Select_MitAuswahl_LiefertVollenSchueler()
    {
        var (vm, anna, _) = Build();
        vm.SelectedStudent = vm.Students.Single(s => s.Id == anna.Id);

        vm.SelectCommand.Execute(null);

        Assert.Equal(anna.Id, vm.Result?.Id);
    }
}