Tests: Add tests:

* Control
* Button
* HiddenField
* HtmlForm
* HyperLink
* Label
* LiteralControl
* Panel
* TextBox
* CTextBox

VAR.WebFormsCore.Tests/Controls/ButtonTests.cs

@@ -0,0 +1,69 @@
+using VAR.WebFormsCore.Controls;
+using VAR.WebFormsCore.Pages;
+using VAR.WebFormsCore.Tests.Fakes;
+using Xunit;
+
+namespace VAR.WebFormsCore.Tests.Controls;
+
+public class ButtonTests
+{
+    [Fact]
+    public void MustRenderCorrectly()
+    {
+        FakeWebContext fakeWebContext = new();
+        Page page = new();
+        Button button = new();
+        page.Controls.Add(button);
+
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal(@"<input type=""submit""  class=""button"" value=""""></input>", result);
+    }
+    
+    [Fact]
+    public void MustRenderCorrectly__WithOnClientClick()
+    {
+        FakeWebContext fakeWebContext = new();
+        Page page = new();
+        Button button = new()
+        {
+            OnClientClick = "alert(1)",
+        };
+        page.Controls.Add(button);
+
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal(@"<input type=""submit""  class=""button"" value="""" onclick=""alert(1)""></input>", result);
+    }
+    
+    [Fact]
+    public void MustRenderCorrectly__ClickWithCommandArgument()
+    {
+        string commandArgument = "Test";
+        FakeWebContext fakeWebContext = new(requestMethod: "POST");
+        Page page = new();
+        Button button = new()
+        {
+            CommandArgument = commandArgument,
+        };
+        string? result = null;
+        button.Click += (o, _) =>
+        {
+            result = (o as Button)?.CommandArgument;
+        };
+        page.Controls.Add(button);
+
+        fakeWebContext.RequestForm.Add(button.ClientID, "Clicked");
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(commandArgument, result);
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+    }
+}

VAR.WebFormsCore.Tests/Controls/CTextBoxTests.cs

@@ -0,0 +1,154 @@
+using VAR.WebFormsCore.Controls;
+using VAR.WebFormsCore.Pages;
+using VAR.WebFormsCore.Tests.Fakes;
+using Xunit;
+
+namespace VAR.WebFormsCore.Tests.Controls;
+
+public class CTextBoxTests
+{
+    #region MustRenderCorrectly
+    
+    [Fact]
+    public void MustRenderCorrectly()
+    {
+        FakeWebContext fakeWebContext = new();
+        Page page = new();
+        CTextBox cTextBox = new();
+        page.Controls.Add(cTextBox);
+
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal(
+            expected: """
+                        <input type="text"  id="ctl00_ctl00" name="ctl00_ctl00" class="textBox" onchange="ElementRemoveClass(this, &#39;textBoxInvalid&#39;);"></input>
+                        """,
+            actual: result);
+    }
+
+    [Fact]
+    public void MustRenderCorrectly__WithMostProperties()
+    {
+        FakeWebContext fakeWebContext = new();
+        Page page = new();
+        CTextBox cTextBox = new()
+        {
+            CssClassExtra = "extraClass", 
+            PlaceHolder = "Placeholder", 
+            MarkedInvalid = true,
+            TextMode = TextBoxMode.Normal, 
+            AllowEmpty = true, 
+            KeepSize = true,
+            Text = "Test",
+        };
+        page.Controls.Add(cTextBox);
+
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal(
+            expected: """
+                        <input type="text"  id="ctl00_ctl00" name="ctl00_ctl00" class="textBox extraClass textBoxInvalid" onchange="ElementRemoveClass(this, &#39;textBoxInvalid&#39;);" placeholder="Placeholder" value="Test"></input>
+                        """,
+            actual: result);
+    }
+    
+    [Fact]
+    public void MustRenderCorrectly__WithNextFocusOnEnter()
+    {
+        FakeWebContext fakeWebContext = new();
+        Page page = new();
+        CTextBox cTextBox = new();
+        page.Controls.Add(cTextBox);
+        CTextBox cTextBox2 = new();
+        page.Controls.Add(cTextBox2);
+        cTextBox.NextFocusOnEnter = cTextBox2;
+
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal(
+            expected: """
+                        <input type="text"  id="ctl00_ctl00" name="ctl00_ctl00" class="textBox" onchange="ElementRemoveClass(this, &#39;textBoxInvalid&#39;);" onkeydown="if(event.keyCode==13){document.getElementById(&#39;ctl01&#39;).focus(); return false;}"></input><input type="text"  id="ctl01_ctl00" name="ctl01_ctl00" class="textBox" onchange="ElementRemoveClass(this, &#39;textBoxInvalid&#39;);"></input>
+                        """,
+            actual: result);
+    }
+    
+    #endregion MustRenderCorrectly
+
+    #region IsEmpty
+
+    [Fact]
+    public void IsEmpty__Empty__True()
+    {
+        CTextBox cTextBox = new() { Text = string.Empty, };
+
+        bool result = cTextBox.IsEmpty();
+        
+        Assert.True(result);
+    }
+    
+    [Fact]
+    public void IsEmpty__Text__False()
+    {
+        CTextBox cTextBox = new() { Text = "Text", };
+
+        bool result = cTextBox.IsEmpty();
+        
+        Assert.False(result);
+    }
+
+    #endregion IsEmpty
+
+    #region IsValid
+
+    [Fact]
+    public void IsEmpty__EmptyAllowEmptyFalse__False()
+    {
+        CTextBox cTextBox = new() { Text = string.Empty, AllowEmpty = false, };
+
+        bool result = cTextBox.IsValid();
+        
+        Assert.False(result);
+    }
+    
+    [Fact]
+    public void IsEmpty__TextAllowEmptyFalse__True()
+    {
+        CTextBox cTextBox = new() { Text = "Text", AllowEmpty = false, };
+
+        bool result = cTextBox.IsValid();
+        
+        Assert.True(result);
+    }
+
+    [Fact]
+    public void IsEmpty__EmptyAllowEmptyTrue__True()
+    {
+        CTextBox cTextBox = new() { Text = string.Empty, AllowEmpty = true, };
+
+        bool result = cTextBox.IsValid();
+        
+        Assert.True(result);
+    }
+    
+    [Fact]
+    public void IsEmpty__TextAllowEmptyTrue__True()
+    {
+        CTextBox cTextBox = new() { Text = "Text", AllowEmpty = true, };
+
+        bool result = cTextBox.IsValid();
+        
+        Assert.True(result);
+    }
+
+    #endregion IsEmpty
+
+}

VAR.WebFormsCore.Tests/Controls/ControlTests.cs

@@ -0,0 +1,25 @@
+using VAR.WebFormsCore.Controls;
+using VAR.WebFormsCore.Pages;
+using VAR.WebFormsCore.Tests.Fakes;
+using Xunit;
+
+namespace VAR.WebFormsCore.Tests.Controls;
+
+public class ControlTests
+{
+    [Fact]
+    public void MustRenderCorrectly__Empty()
+    {
+        FakeWebContext fakeWebContext = new();
+        Page page = new();
+        Control control = new();
+        page.Controls.Add(control);
+
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal("", result);
+    }
+}

VAR.WebFormsCore.Tests/Controls/HiddenFieldTests.cs

@@ -0,0 +1,63 @@
+using VAR.WebFormsCore.Controls;
+using VAR.WebFormsCore.Pages;
+using VAR.WebFormsCore.Tests.Fakes;
+using Xunit;
+
+namespace VAR.WebFormsCore.Tests.Controls;
+
+public class HiddenFieldTests
+{
+    [Fact]
+    public void MustRenderCorrectly()
+    {
+        FakeWebContext fakeWebContext = new();
+        Page page = new();
+        HiddenField hiddenField = new();
+        page.Controls.Add(hiddenField);
+
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal(@"<input type=""hidden""  id=""ctl00"" name=""ctl00""></input>", result);
+    }
+    
+    [Fact]
+    public void MustRenderCorrectly__WithValue()
+    {
+        string value = "Test";
+        FakeWebContext fakeWebContext = new();
+        Page page = new();
+        HiddenField hiddenField = new() { Value = value };
+        page.Controls.Add(hiddenField);
+
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(value, hiddenField.Value);
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal(@"<input type=""hidden""  id=""ctl00"" name=""ctl00"" value=""Test""></input>", result);
+    }
+    
+    [Fact]
+    public void MustRenderCorrectly__WithChangedValue()
+    {
+        string value = "Test";
+        string changedValue = "Changed";
+        FakeWebContext fakeWebContext = new(requestMethod: "POST");
+        Page page = new();
+        HiddenField hiddenField = new() { Value = value };
+        page.Controls.Add(hiddenField);
+
+        fakeWebContext.RequestForm.Add(hiddenField.ClientID, changedValue);
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(changedValue, hiddenField.Value);
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal(@"<input type=""hidden""  id=""ctl00"" name=""ctl00"" value=""Changed""></input>", result);
+    }
+}

VAR.WebFormsCore.Tests/Controls/HtmlFormTests.cs

@@ -0,0 +1,42 @@
+using VAR.WebFormsCore.Controls;
+using VAR.WebFormsCore.Pages;
+using VAR.WebFormsCore.Tests.Fakes;
+using Xunit;
+
+namespace VAR.WebFormsCore.Tests.Controls;
+
+public class HtmlFormTests
+{
+    [Fact]
+    public void MustRenderCorrectly()
+    {
+        FakeWebContext fakeWebContext = new();
+        Page page = new();
+        HtmlForm htmlForm = new();
+        page.Controls.Add(htmlForm);
+
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal(@"<form  method=""post"" action=""Page""></form>", result);
+    }
+    
+    [Fact]
+    public void MustRenderCorrectly__WithQueryParameters()
+    {
+        FakeWebContext fakeWebContext = new();
+        fakeWebContext.RequestQuery.Add("test", "value");
+        Page page = new();
+        HtmlForm htmlForm = new();
+        page.Controls.Add(htmlForm);
+
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal(@"<form  method=""post"" action=""Page?&amp;test=value""></form>", result);
+    }
+}

VAR.WebFormsCore.Tests/Controls/HtmlHeadTests.cs

@@ -24,7 +24,7 @@ public class HtmlHeadTests
     }
     
     [Fact]
-    public void MustRenderCorrectlyWithTitle()
+    public void MustRenderCorrectly__WithTitle()
     {
         FakeWebContext fakeWebContext = new();
         Page page = new();
@@ -41,7 +41,7 @@ public class HtmlHeadTests
     }
     
     [Fact]
-    public void MustRenderCorrectlyWithMeta()
+    public void MustRenderCorrectly__WithMeta()
     {
         FakeWebContext fakeWebContext = new();
         Page page = new();

VAR.WebFormsCore.Tests/Controls/HyperLinkTests.cs

@@ -0,0 +1,45 @@
+using VAR.WebFormsCore.Controls;
+using VAR.WebFormsCore.Pages;
+using VAR.WebFormsCore.Tests.Fakes;
+using Xunit;
+
+namespace VAR.WebFormsCore.Tests.Controls;
+
+public class HyperLinkTests
+{
+    [Fact]
+    public void MustRenderCorrectly()
+    {
+        FakeWebContext fakeWebContext = new();
+        Page page = new();
+        HyperLink hyperLink = new();
+        page.Controls.Add(hyperLink);
+
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal("<a ></a>", result);
+    }
+    
+    [Fact]
+    public void MustRenderCorrectly__WithTextAndUrl()
+    {
+        FakeWebContext fakeWebContext = new();
+        Page page = new();
+        HyperLink hyperLink = new()
+        {
+            NavigateUrl = "http://example.com",
+            Text = "Example.com"
+        };
+        page.Controls.Add(hyperLink);
+
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal(@"<a  href=""http://example.com"">Example.com</a>", result);
+    }
+}

VAR.WebFormsCore.Tests/Controls/LabelTests.cs

@@ -0,0 +1,25 @@
+using VAR.WebFormsCore.Controls;
+using VAR.WebFormsCore.Pages;
+using VAR.WebFormsCore.Tests.Fakes;
+using Xunit;
+
+namespace VAR.WebFormsCore.Tests.Controls;
+
+public class LabelTests
+{
+    [Fact]
+    public void MustRenderCorrectly()
+    {
+        FakeWebContext fakeWebContext = new();
+        Page page = new();
+        Label label = new();
+        page.Controls.Add(label);
+
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal("<span ></span>", result);
+    }
+}

VAR.WebFormsCore.Tests/Controls/LiteralControlTests.cs

@@ -0,0 +1,42 @@
+using VAR.WebFormsCore.Controls;
+using VAR.WebFormsCore.Pages;
+using VAR.WebFormsCore.Tests.Fakes;
+using Xunit;
+
+namespace VAR.WebFormsCore.Tests.Controls;
+
+public class LiteralControlTests
+{
+    [Fact]
+    public void MustRenderCorrectly__Empty()
+    {
+        FakeWebContext fakeWebContext = new();
+        Page page = new();
+        LiteralControl literalControl = new();
+        page.Controls.Add(literalControl);
+
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal(@"", result);
+    }
+    
+    [Fact]
+    public void MustRenderCorrectly__AnyContent()
+    {
+        string anyContent = "AnyContent<script>alert(1)</script>";
+        FakeWebContext fakeWebContext = new();
+        Page page = new();
+        LiteralControl literalControl = new(anyContent);
+        page.Controls.Add(literalControl);
+
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal(anyContent, result);
+    }
+}

VAR.WebFormsCore.Tests/Controls/PanelTests.cs

@@ -0,0 +1,25 @@
+using VAR.WebFormsCore.Controls;
+using VAR.WebFormsCore.Pages;
+using VAR.WebFormsCore.Tests.Fakes;
+using Xunit;
+
+namespace VAR.WebFormsCore.Tests.Controls;
+
+public class PanelTests
+{
+    [Fact]
+    public void MustRenderCorrectly()
+    {
+        FakeWebContext fakeWebContext = new();
+        Page page = new();
+        Panel panel = new();
+        page.Controls.Add(panel);
+
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal("<div ></div>", result);
+    }
+}

VAR.WebFormsCore.Tests/Controls/TextBoxTests.cs

@@ -0,0 +1,154 @@
+using VAR.WebFormsCore.Controls;
+using VAR.WebFormsCore.Pages;
+using VAR.WebFormsCore.Tests.Fakes;
+using Xunit;
+
+namespace VAR.WebFormsCore.Tests.Controls;
+
+public class TextBoxTests
+{
+    [Fact]
+    public void MustRenderCorrectly__Normal()
+    {
+        FakeWebContext fakeWebContext = new();
+        Page page = new();
+        TextBox textBox = new();
+        page.Controls.Add(textBox);
+
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal(
+            expected: """
+                        <input type="text"  id="ctl00" name="ctl00"></input>
+                        """,
+            actual: result);
+    }
+    
+    [Fact]
+    public void MustRenderCorrectly__NormalWithText()
+    {
+        FakeWebContext fakeWebContext = new();
+        Page page = new();
+        TextBox textBox = new() { Text = "Text", };
+        page.Controls.Add(textBox);
+
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal(
+            expected: """
+                        <input type="text"  id="ctl00" name="ctl00" value="Text"></input>
+                        """,
+            actual: result);
+    }
+    
+    [Fact]
+    public void MustRenderCorrectly__Password()
+    {
+        FakeWebContext fakeWebContext = new();
+        Page page = new();
+        TextBox textBox = new() {TextMode = TextBoxMode.Password, };
+        page.Controls.Add(textBox);
+
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal(
+            expected: """
+                        <input type="password"  id="ctl00" name="ctl00"></input>
+                        """,
+            actual: result);
+    }
+    
+    [Fact]
+    public void MustRenderCorrectly__PasswordWithText()
+    {
+        FakeWebContext fakeWebContext = new();
+        Page page = new();
+        TextBox textBox = new() { TextMode = TextBoxMode.Password, Text = "Password", };
+        page.Controls.Add(textBox);
+
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal(
+            expected: """
+                        <input type="password"  id="ctl00" name="ctl00" value="Password"></input>
+                        """,
+            actual: result);
+    }
+    
+    [Fact]
+    public void MustRenderCorrectly__MultiLine()
+    {
+        FakeWebContext fakeWebContext = new();
+        Page page = new();
+        TextBox textBox = new() {TextMode = TextBoxMode.MultiLine, };
+        page.Controls.Add(textBox);
+
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal(
+            expected: """
+                        <textarea  id="ctl00" name="ctl00"></textarea>
+                        """,
+            actual: result);
+    }
+    
+    [Fact]
+    public void MustRenderCorrectly__MultiLineWithText()
+    {
+        FakeWebContext fakeWebContext = new();
+        Page page = new();
+        TextBox textBox = new() { TextMode = TextBoxMode.MultiLine, Text = "Multi\nLine", };
+        page.Controls.Add(textBox);
+
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal(
+            expected: """
+                        <textarea  id="ctl00" name="ctl00">Multi
+                        Line</textarea>
+                        """,
+            actual: result);
+    }
+    
+    [Fact]
+    public void MustRenderCorrectly__WithChangedText()
+    {
+        string text = "Test";
+        string changedValue = "Changed";
+        FakeWebContext fakeWebContext = new(requestMethod: "POST");
+        Page page = new();
+        TextBox textBox = new() { Text = text };
+        page.Controls.Add(textBox);
+
+        fakeWebContext.RequestForm.Add(textBox.ClientID, changedValue);
+        page.ProcessRequest(fakeWebContext);
+
+        Assert.Equal(changedValue, textBox.Text);
+        Assert.Equal(200, fakeWebContext.ResponseStatusCode);
+        Assert.Equal("text/html", fakeWebContext.ResponseContentType);
+        string result = fakeWebContext.FakeWritePackages.ToString("");
+        Assert.Equal(
+            expected: """
+                        <input type="text"  id="ctl00" name="ctl00" value="Changed"></input>
+                        """,
+            actual: result);
+    }
+}

VAR.WebFormsCore/Controls/CTextBox.cs

@@ -113,7 +113,7 @@ public class CTextBox : Control, INamingContainer, IValidableControl
 
     #region Public methods
 
-    private bool IsEmpty() { return string.IsNullOrEmpty(_txtContent.Text); }
+    public bool IsEmpty() { return string.IsNullOrEmpty(_txtContent.Text); }
 
     public bool IsValid() { return AllowEmpty || (string.IsNullOrEmpty(_txtContent.Text) == false); }
 

VAR.WebFormsCore/Controls/Control.cs

@@ -25,7 +25,6 @@ public class Control
         foreach (Control control in Controls) { control.OnInit(e); }
     }
 
-
     public event EventHandler? Load;
 
     protected virtual void Process() { }