为Asp.net控件写单元测试(ViewState)

发布: 2009-4-10 09:16 | 作者: 不详 | 来源: 测试时代采编 | 查看: 26次 | 进入软件测试论坛讨论

通常一个典型的asp.net控件至少会用ViewState存储一些属性,以便于在页面postback后不用重新设置。在这篇文章里我将介绍如何为控件写单元测试，以确保一个属性被正确的保存在ViewState里。

为了演示，我写了一个简单的控件。

namespace Eilon.Sample.Controls {
using System;
using System.Web.UI;
public class NewLabel : Control {
public string Text {
get {
string s = ViewState["Text"] as string;
return s ?? String.Empty;
}
set {
ViewState["Text"] = value;
}
}
protected override void Render(HtmlTextWriter writer) {
writer.Write(Text);
}
}
}

这个控件只是简单的将它唯一的属性Text输出。

好的，让我们写一个简单的单元测试，以确保这个控件正确的工作。

namespace Eilon.Sample.Controls.Test {
using System;
using System.IO;
using System.Web.UI;
using Microsoft.VisualStudio.TestTools.UnitTesting;
[TestClass]
public class NewLabelTest {
[TestMethod]
public void TextReturnsEmptyStringDefault() {
NewLabel label = new NewLabel();
Assert.AreEqual(String.Empty, label.Text,

"Default text should be empty string (not null)");
}
[TestMethod]
public void GetSetText() {
const string value = "Some Text";
NewLabel label = new NewLabel();
label.Text = value;
Assert.AreEqual(value, label.Text,

"Property value isn't the same as what we set");
}
[TestMethod]
public void RenderEmpty() {
NewLabel label = new NewLabel();
Assert.AreEqual(String.Empty, GetRenderedText(label),

"Shouldn't have rendered anything");
}
[TestMethod]
public void RenderWithText() {
const string value = "Some Text";
NewLabel label = new NewLabel();
label.Text = value;
Assert.AreEqual(value, GetRenderedText(label),

"Should have rendered the text");
}
private static string GetRenderedText(Control c) {
HtmlTextWriter writer = new HtmlTextWriter(new StringWriter());
c.RenderControl(writer);
return writer.InnerWriter.ToString();
}
}
}