Example of data source plugin for Visual Studio Webtests

AnnotationsDataSourcePlugin.cs

using System.ComponentModel;
using Hudl.WebApp.Tests.TestsCore.DataSources;
using Microsoft.VisualStudio.TestTools.WebTesting;

namespace Hudl.WebApp.Tests.TestsCore.Plugins
{
    [DisplayName("Annotations DataSource")]
    [Description("Reads Annotation IDs from the context and assigns values to context parameters.")]
    public class AnnotationsDataSourcePlugin : WebTestPlugin
    {
        [DisplayName("DataSource Context Parameter Name")]
        [Description("The name of the context parameter which holds the DataSource object.")]
        [DefaultValue("AnnotationsDataSource")]
        public string DataSourceContextParameterName { get; set; }

        [DisplayName("AnnotationId Context Parameter Name")]
        [Description("The name of the context parameter which will be assigned the annotation ID value.")]
        [DefaultValue("AnnotationId")]
        public string AnnotationIdContextParameterName { get; set; }

        public override void PreWebTest(object sender, PreWebTestEventArgs e)
        {
            base.PreWebTest(sender, e);
            var webTextContext = e.WebTest.Context;

            var annotationsDataSource = webTextContext[DataSourceContextParameterName] as IDataSource<long>;

            var annotationId = annotationsDataSource.GetNext();
            webTextContext[AnnotationIdContextParameterName] = annotationId;
        }
    }
}