public void ExtensionNotSupportedTest()
{
// Tests that calling RenderPage on an unsupported extension returns a new simpler error message
// instead of the full error about build providers in system.web.dll.
var vpath = "~/hello/world.txt";
var ext = ".txt";
var compilationUtilThrowingBuildManager = new CompilationUtil();
var otherExceptionBuildManager = new Mock<IVirtualPathFactory>();
var msg = "The file \"~/hello/world.txt\" could not be rendered, because it does not exist or is not a valid page.";
otherExceptionBuildManager.Setup(c => c.CreateInstance(It.IsAny<string>())).Throws(new HttpException(msg));
Assert.Throws<HttpException>(() =>
WebPage.CreateInstanceFromVirtualPath(vpath, new VirtualPathFactoryManager(compilationUtilThrowingBuildManager)),
String.Format(CultureInfo.CurrentCulture, WebPageResources.WebPage_FileNotSupported, ext, vpath));
// Test that other error messages are thrown unmodified.
Assert.Throws<HttpException>(() => WebPage.CreateInstanceFromVirtualPath(vpath, otherExceptionBuildManager.Object), msg);
}