DotNetAngular/tests/Application.UnitTest/DTOs/PagedResultTests.cs

using Application.DTOs;

namespace Application.UnitTest.DTOs;

public class PagedResultTests
{
    [Fact]
    public void TotalPages_ShouldCalculateCorrectly_WhenExactDivision()
    {
        var paged = new PagedResult<string>
        {
            Items = ["a", "b", "c", "d", "e"],
            TotalCount = 5,
            PageNumber = 1,
            PageSize = 5
        };
        Assert.Equal(1, paged.TotalPages);
    }

    [Fact]
    public void TotalPages_ShouldRoundUp_WhenNotExactDivision()
    {
        var paged = new PagedResult<string>
        {
            Items = ["a", "b", "c"],
            TotalCount = 10,
            PageNumber = 1,
            PageSize = 3
        };
        Assert.Equal(4, paged.TotalPages);
    }

    [Fact]
    public void TotalPages_ShouldBeZero_WhenTotalCountIsZero()
    {
        var paged = new PagedResult<string>
        {
            Items = [],
            TotalCount = 0,
            PageNumber = 1,
            PageSize = 10
        };
        Assert.Equal(0, paged.TotalPages);
    }

    [Fact]
    public void HasPreviousPage_ShouldBeFalse_WhenOnFirstPage()
    {
        var paged = new PagedResult<string>
        {
            Items = [],
            TotalCount = 20,
            PageNumber = 1,
            PageSize = 10
        };
        Assert.False(paged.HasPreviousPage);
    }

    [Fact]
    public void HasPreviousPage_ShouldBeTrue_WhenPastFirstPage()
    {
        var paged = new PagedResult<string>
        {
            Items = [],
            TotalCount = 20,
            PageNumber = 2,
            PageSize = 10
        };
        Assert.True(paged.HasPreviousPage);
    }

    [Fact]
    public void HasNext_ShouldBeFalse_WhenOnLastPage()
    {
        var paged = new PagedResult<string>
        {
            Items = [],
            TotalCount = 20,
            PageNumber = 2,
            PageSize = 10
        };
        Assert.False(paged.HasNext);
    }

    [Fact]
    public void HasNext_ShouldBeTrue_WhenMorePagesExist()
    {
        var paged = new PagedResult<string>
        {
            Items = [],
            TotalCount = 20,
            PageNumber = 1,
            PageSize = 10
        };
        Assert.True(paged.HasNext);
    }

    [Fact]
    public void HasNext_ShouldBeFalse_WhenOnlyOnePage()
    {
        var paged = new PagedResult<string>
        {
            Items = [],
            TotalCount = 3,
            PageNumber = 1,
            PageSize = 10
        };
        Assert.False(paged.HasNext);
    }
}