PixiEditor/src/PixiEditorTests/ModelsTests/DataHoldersTests/SelectionTests.cs

using PixiEditor.Helpers;
using PixiEditor.Models.DataHolders;
using PixiEditor.Models.Enums;
using PixiEditor.Models.Position;
using System;
using System.Collections.Generic;
using Xunit;

namespace PixiEditorTests.ModelsTests.DataHoldersTests;

public class SelectionTests
{
    [Fact]
    public void TestThatSetSelectionNewSetsCorrectSelection()
    {
        Selection selection = new Selection(Array.Empty<Coordinates>(), new(10, 10));
        Coordinates[] points = { new Coordinates(0, 0), new Coordinates(1, 1) };

        selection.SetSelection(points, SelectionType.New);
        selection.SetSelection(points, SelectionType.New); // Doing it twice, to check if it sets every time properly

        Assert.Equal(points.Length, selection.SelectedPoints.Count);
    }

    [Fact]
    public void TestThatSetSelectionAddSetsCorrectSelection()
    {
        Selection selection = new Selection(Array.Empty<Coordinates>(), new PixelSize(10, 10));
        Coordinates[] points = { new Coordinates(0, 0), new Coordinates(1, 1) };
        Coordinates[] points2 = { new Coordinates(2, 4), new Coordinates(5, 7) };

        selection.SetSelection(points, SelectionType.Add);
        selection.SetSelection(points2, SelectionType.Add); // Doing it twice, to check if it sets every time properly

        Assert.Equal(points.Length + points2.Length, selection.SelectedPoints.Count);
    }

    [Fact]
    public void TestThatSetSelectionSubtractSetsCorrectSelection()
    {
        Selection selection = new Selection(Array.Empty<Coordinates>(), new PixelSize(10, 10));
        Coordinates[] points = { new Coordinates(0, 0), new Coordinates(1, 1) };
        Coordinates[] points2 = { new Coordinates(1, 1) };

        selection.SetSelection(points, SelectionType.Add);
        selection.SetSelection(points2, SelectionType.Subtract); // Doing it twice, to check if it sets every time properly

        Assert.Single(selection.SelectedPoints);
    }

    [Fact]
    public void TestClearWorks()
    {
        Selection selection = new Selection(new[] { new Coordinates(0, 0), new Coordinates(5, 7) }, new PixelSize(10, 10));
        selection.Clear();

        Assert.Empty(selection.SelectedPoints);
        Assert.Equal(1, selection.SelectionLayer.Width);
        Assert.Equal(1, selection.SelectionLayer.Height);
    }

    [Fact]
    public void TestThatUndoWorks()
    {
        using Document document = new Document(10, 10);

        IEnumerable<Coordinates> oldSelection = new List<Coordinates>(document.ActiveSelection.SelectedPoints);

        document.ActiveSelection.SetSelection(new[] { new Coordinates(0, 0), new Coordinates(5, 7) }, SelectionType.Add);

        Assert.NotEqual(oldSelection, document.ActiveSelection.SelectedPoints);

        SelectionHelpers.AddSelectionUndoStep(document, oldSelection, SelectionType.Add);

        document.UndoManager.Undo();

        Assert.Equal(oldSelection, document.ActiveSelection.SelectedPoints);
    }
}