LehrerApp/LehrerApp.Data.Tests/ChangeHookTests.cs

using LehrerApp.Core.Models;
using LehrerApp.Data.Repositories;
using Xunit;

namespace LehrerApp.Data.Tests;

// Vorlage-Test für den OnChange-Hook (Baustein 2), den die übrigen Repositories in den
// Bausteinen 3/4 auf dieselbe Weise bekommen.
public sealed class ChangeHookTests
{
    private static LiteDbContext NewInMemoryContext() => new(new MemoryStream());

    [Fact]
    public void StudentRepository_Save_LoestOnChangeMitKorrektenArgumentenAus()
    {
        using var db = NewInMemoryContext();
        var calls = new List<(string EntityType, string EntityId, string Operation, object? Payload)>();
        db.OnChange = (type, id, op, payload) => calls.Add((type, id, op, payload));
        var repo = new StudentRepository(db);
        var student = new Student { FirstName = "Anna", LastName = "Beispiel" };

        repo.Save(student);

        var call = Assert.Single(calls);
        Assert.Equal("Student", call.EntityType);
        Assert.Equal(student.Id.ToString(), call.EntityId);
        Assert.Equal("Save", call.Operation);
        Assert.Same(student, call.Payload);
    }

    [Fact]
    public void StudentRepository_Delete_LoestOnChangeMitNullPayloadAus()
    {
        using var db = NewInMemoryContext();
        var repo = new StudentRepository(db);
        var student = new Student { FirstName = "Anna", LastName = "Beispiel" };
        repo.Save(student);
        var calls = new List<(string EntityType, string EntityId, string Operation, object? Payload)>();
        db.OnChange = (type, id, op, payload) => calls.Add((type, id, op, payload));

        repo.Delete(student.Id);

        var call = Assert.Single(calls);
        Assert.Equal("Student", call.EntityType);
        Assert.Equal(student.Id.ToString(), call.EntityId);
        Assert.Equal("Delete", call.Operation);
        Assert.Null(call.Payload);
    }

    [Fact]
    public void StudentRepository_Save_OhneGesetztenHook_WirftNicht()
    {
        using var db = NewInMemoryContext();
        var repo = new StudentRepository(db);

        var exception = Record.Exception(() => repo.Save(new Student { FirstName = "Anna", LastName = "Beispiel" }));

        Assert.Null(exception);
    }
}