migrate-iie-iselenium.md

Migrate from IIE to ISelenium

• Add Selenium NuGet packages
  • For a specific browser ...
  • ... or Edge
    • Abandoning Interop.SHDocVw
  • Selenium.WebDriver for ASP.NET Framework tests
• Exchange project references
  • Replace using directives
• Generic test classes
• Fixed compatibility caveats

Add Selenium NuGet packages

For a specific browser ...

While for IIE, the COM references to Interop.MSHTML and Interop.SHDocVw were only required in the library itself, some NuGet packages must be added to the web/test projects, too (similar to NUnit itself).

The ISelenium library only references the generic Selenium.WebDriver to communicate with the browser. Therefore, the concrete WebDriver NuGet package is required for the web project, either Selenium.InternetExplorer.WebDriver (32 bit), Selenium.Firefox.WebDriver or Selenium.Chrome.WebDriver.

... or Edge

The case for Edge is different, as the WebDriver is integrated into the win10 operating system as an official Windows Feature on Demand. Go to Apps in the win10 Settings, click on Optional Features and Add Feature, then look for the "Microsoft WebDriver" and install it.

Additionally, Developer Mode must be enabled. Go to Settings > Update and Security > For Developer and then select "Developer mode".

Even more, in Edge itself, access to localhost must be enabled. Type about:flags in the URL bar and enable the "Localhost-Loopback".

Abandoning Interop.SHDocVw

However, this will not enable the now blocked http://127.0.0.1 (to ptotect local webservices from malicious CORS requests from a remote web site, see e.g. Hacker News - I can see your local web servers) or Hacker News - Why Is This Website Port Scanning Me?. No http://127.0.0.1 no more is the main reason why IIE with direct COM communication is now abandoned, although it was by far the fastest test driver. No more tweak the solution because "localhost" seems to never reach OnDocumentComplete (in iie.IEExtension). Its inability to communicate with SPA pages like the minimal.websharper.spa was another big reason.

Selenium.WebDriver for ASP.NET Framework tests

Unlike for .NET Core, the NUnit test project for ASP.NET Framework also requires the generic Selenium.WebDriver to be installed in the project itself, the indirect reference via iselenium.webforms is not enough.

Exchange project references

Delete the iie.webforms resp. iie.core and the parent iie project references and replace them with iselenium.webforms resp. iselenium.core in both the web project and its corresponding NUnit test project. For .NET core, the parent iselenium reference is only needed in the web project itself.

Replace using directives

After the iie references have been removed, Visual Studio will automatically complain - it should suffice to replace

using iie;

with

using iselenium;

in all test sources and, in case of .NET Core, in the Controller class for the page containing the NUnit button to start the test.

For ASP.NET Framework, the Register Assembly directive in the .ascx file containing the NUnit button must be adjusted as well. Replace

<%@ Register Assembly="iie.webforms" Namespace="iie" TagPrefix="iie" %>

with

<%@ Register Assembly="iselenium.webforms" Namespace="iselenium" TagPrefix="iie" %>

The TagPrefix="iie" can remain as is.

Generic test classes

If you don’t want to use the obsolete non-generic IETest base classes for Internet Explorer, the concrete browser to perform tests with needs to be declared in the TestFixture. Multiple declarations are allowed, which will execute all tests with each of the given browsers:

    [TestFixture(typeof(EdgeDriver))]
    [TestFixture(typeof(ChromeDriver))]
    [TestFixture(typeof(FirefoxDriver))]
    [TestFixture(typeof(InternetExplorerDriver))]

Make sure to add the corresponding NuGet packages for the browser-specific WebDriver.

Fixed compatibility caveats

getElementsByName

The getElementsByName() method in an IHTMLDocument3 instance from Interop.MSHTML implicitly returns an HTMLElement with that id instead of the given name if the latter is not founc. This behavior has been replicated in SeleniumExtensionBase.GetHTMLElementByName() (which by itself ignores the id) to retain compatibility.

Line Breaks

Line breaks in a MSHTML.IHTMLDocument2.body.outerHTML are only LF (\n), while line breaks returned by Seleniums GetAttribute("outerHTML") are Windows-style CR LF (\r\n). To retain compatiblity with hackish test assertions like Assert.That(this.Html(), Does.Contain(" 5\n"), this has been mitigated by returning only LF (\n), too.