2011-01-26 How to UnitTest your WebControls rendered HTML

2011-01-26 unittest-how-your-webcontrols-render

# Title: How to UnitTest your WebControls rendered HTML
# Author: Mikael Lundin
# Link: http://blog.mikaellundin.name/2011/01/26/unittest-how-your-webcontrols-render.html

Example1.cs

var ul = string.Format("<ul{0}{1}>",
    string.IsNullOrEmpty(cssClass) ? string.Empty : string.Format(@" class=""{0}""", cssClass),
    string.IsNullOrEmpty(xmlns) ? string.Empty : string.Format(@" xmlns=""{0}""", xmlns));</ul{0}{1}>

Example2.cs

const string Xmlns = "urn:unordered-radio-button-list";
var control = new Template { DataSource = data, Xmlns = Xmlns };

RadioButtonList.html

<?xml version="1.0" encoding="utf-8" ?>
<ul xmlns="urn:unordered-radio-button-list">
  <li>
    <input id="bananas" name="bananas" type="radio" value="Bananas"  />
    <label for="bananas">I like bananas</label>
  </li>
  <li>
    <input id="onions" name="onions" type="radio" value="Onions"  />
    <label for="onions">I like onions</label>
  </li>
</ul>

schema.xsd

<?xml version="1.0" encoding="utf-8"?>
<xs:schema id="UnorderedRadioButtonList"
    targetNamespace="urn:unordered-radio-button-list"
    elementFormDefault="qualified"
    xmlns="urn:unordered-radio-button-list"
    xmlns:mstns="http://www.litemedia.se/UnorderedRadioButtonList.xsd"
    xmlns:xs="http://www.w3.org/2001/XMLSchema">
 
  <!-- Root element -->
  <xs:element name="ul">
    <xs:complexType>
 
      <!-- Unbounded number of elements -->
      <xs:sequence maxOccurs="unbounded">
        <xs:element ref="li" />
      </xs:sequence>
    </xs:complexType>
  </xs:element>
 
  <!-- The LI element-->
  <xs:element id="li" name="li">
    <xs:complexType>
      <xs:sequence>
        <xs:element ref="input" />
        <xs:element ref="label" />
      </xs:sequence>
    </xs:complexType>
  </xs:element>
 
  <!-- input element has only attributes -->
  <xs:element id="input" name="input">
    <xs:complexType>
      <xs:attribute name="id" type="xs:string"></xs:attribute>
      <xs:attribute name="name" type="xs:string"></xs:attribute>
      <xs:attribute name="type" type="xs:string" fixed="radio"></xs:attribute>
      <xs:attribute name="value" type="xs:string"></xs:attribute>
    </xs:complexType>
  </xs:element>
 
  <!-- label contains for attribute and content -->
  <xs:element id="label" name="label">
    <xs:complexType>
      <xs:simpleContent>
        <xs:extension base="xs:string">
          <xs:attribute name="for" type="xs:string"></xs:attribute>
        </xs:extension>
      </xs:simpleContent>
    </xs:complexType>
  </xs:element>
</xs:schema>

UnorderedRadioButtonListShould.cs

namespace LiteMedia.Web.UI.WebControls.Test
{
    using System.IO;
    using System.Reflection;
    using System.Web.UI;
    using System.Web.UI.WebControls;
    using System.Xml;
    using NUnit.Framework;
    using System.Xml.Schema;
 
    [TestFixture]
    public class UnorderedRadioButtonListShould
    {
        /* This private class is used to reach protected members in our SUT */
        private class Template : ULRadioButtonList
        {
            public new void Render(HtmlTextWriter htmlTextWriter)
            {
                base.Render(htmlTextWriter);
            }
        }
 
        [Test]
        public void ProduceExpectedHtmlMarkup()
        {
            /* Prepare some static variables */
            const string Xmlns = "urn:unordered-radio-button-list";
            var schema = GetType().Namespace + ".UnorderedRadioButtonList.xsd";
 
            /* Radio button list data source
             * <input type="radio" value="Bananas" /><label>I like bananas</label>
             * <input type="radio" value="Onions" /><label>I like onions</label>
             */
            var data = new ListItemCollection
            {
                new ListItem("I like bananas", "Bananas"),
                new ListItem("I like onions", "Onions")
            };
 
            /* SUT */
            var control = new Template { DataSource = data  };
            control.DataBind();
 
            /* Prepare render output stream */
            var htmlOutputStream = new MemoryStream();
            var htmlOutputStreamWriter = new StreamWriter(htmlOutputStream);
            var htmlWriter = new HtmlTextWriter(htmlOutputStreamWriter);
 
            /* Test */
            control.Render(htmlWriter);
            htmlWriter.Flush();
 
            /* Assert */
            htmlOutputStream.Position = 0; /* Reset stream */
 
            /* Load the schema */
            var xsdStream = Assembly.GetExecutingAssembly().GetManifestResourceStream(schema);
            var xmlSchema = XmlReader.Create(xsdStream);
 
            /* Create xml reader and set schema for validation */
            var settings = new XmlReaderSettings();
            settings.Schemas.Add(Xmlns, xmlSchema);
            settings.ValidationType = ValidationType.Schema;
 
 
            // Trigger this event on schema validation errors
            settings.ValidationEventHandler += HandleValidationErrors;
 
            // Read and validate htmlOutputStream
            var xmlValidatingReader = XmlReader.Create(htmlOutputStream, settings);
            while (xmlValidatingReader.Read()) ;
        }
 
        private void HandleValidationErrors(object sender, ValidationEventArgs e)
        {
            // There was validation errors, fail with message
            Assert.Fail(e.Message);
        }
    }
}