I am using Umbraco 10.

I am trying to create Document types from code. I noticed that whenever the property alias is having underscore ("_") character in it's Alias, it is getting removed. For some reason we need to keep the underscore character in it. Here is sample piece of code that I am using (for testing purpose the code is placed in a template/razor view) -

@using Umbraco.Cms.Core;
@using Umbraco.Cms.Core.Strings;
@using Umbraco.Cms.Core.Models;
@using Umbraco.Cms.Web.Common.PublishedModels;
@using Umbraco.Cms.Core.IO;
@using Umbraco.Cms.Core.Services;
@using Umbraco.Extensions;
@using System.IO;
@using Umbraco.Cms.Core.PropertyEditors
@using Umbraco.Cms.Core.Models.Editors;

@inherits Umbraco.Cms.Web.Common.Views.UmbracoViewPage;

@inject IContentTypeService ContentTypeService
@inject IDataTypeService DataTypeService
@{
    Layout = null;


    DefaultShortStringHelperConfig.Config helperconfig = new DefaultShortStringHelperConfig.Config();
    helperconfig.StringType = CleanStringType.Unchanged;

    DefaultShortStringHelperConfig config = new DefaultShortStringHelperConfig();
    config = config.WithConfig(CleanStringType.Unchanged, helperconfig);

    var stringhelper = new DefaultShortStringHelper(config);


    var ct = new ContentType(stringhelper, -1);
    ct.Name = "TestDocumentType";
    ct.Alias = "testDocumentType";

    // properties
    PropertyType pt = new PropertyType(stringhelper, "Umbraco.Textbox", ValueStorageType.Nvarchar);
    pt.Name = "Name_test";
    pt.Alias = "name_test";
    ct.AddPropertyType(pt);
    pt = new PropertyType(stringhelper, "Umbraco.Textbox", ValueStorageType.Nvarchar);
    pt.Name = "Property2_Test";
    pt.Alias = "property2_test";
    ct.AddPropertyType(pt);

    ct.Icon = "icon-defrag color-red";
    ct.AllowedAsRoot = true;

    //ContentTypeService.Save(ct);
}

When debugging, it is noticed that after assigning the value to Alias, Umbraco is cleaning up the value and removing the underscore character. This is due to PropertyType.cs class in umbraco does the cleaning for Alias value. We need to override this default behavior but not able to do so. In above example tried with providing CleanString type in configuration but not works.

Will be great help if you have any solution to above scenario.

Thanks.