This document discusses the development of WinAppDriver. It provides an overview of WinAppDriver and describes its key components, including the HTTP server, request manager, session manager, and handlers. It also covers environment setup, the JSON/WebDriver wire protocol, and future TODO items like improving the build system and implementing remaining WebDriver commands. The goal of WinAppDriver is to enable test automation of Windows desktop and store apps via a WebDriver-compatible API.

1. WinAppDriver Development
Jeremy Kao (about.me/imsardine) @ KKBOX SQA
17/12/2014

2. Agenda
• Environment Setup
• JSON Wire/WebDriver Protocol
and Routing
• WinAppDriver Components
• TODO

3. WinAppDriver Overview
Test
WinAppDriver
UIA Client API
WPFWinFormsWin32
http://*:4444/wd/hub
Test
Windows DevicesWin & Unix-like
JSON/WebDriver!
Wire Protocol
Lang.
Bindings

4. DEV Environment Setup
• Prerequisites
• .NET Framework 3.0 (Vista) and above.
• Windows SDK
• Configure PATH environment variable
SET PATH=%PATH%;C:WindowsMicrosoft.NETFramework<VERSION>;C:
Program Files (x86)Windows Kits<VERSION>bin<ARCH>
• Get the source code from GitHub
git clone git@github.com:imsardine/winappdriver.git
• Build the project
msbuild.exe src/ActivateStoreApp/ActivateStoreApp.csproj
msbuild.exe src/WinAppDriver/WinAppDriver.csproj

5. Deployment
• Prerequisites
• .NET Framework 3.0 (Vista) and above.
• Windows 8.0 and above for store apps.
• Configure firewall and URL namespace reservations.
• Import WinAppDriver Test Certificate to Trusted Root
Certification Authorities store.
• Copy the following files to a secure location
WinAppDriver.exe, ActivateStoreApp.exe, Newtonsoft.Json.dll

6. JSON/WebDriver Wire Protocol
• The WebDriver Wire Protocol - Selenium
• For example
• Find an element
POST session/:sessionId/element
• Click an element
POST session/:sessionId/element/:id/click

7. Routing
• Endpoints
POST session/:sessionId/element
• Handlers with Route attribute (WinAppDriver.RouteAttribute)
[Route("POST", "/session/:sessionId/element")]
class FindElementHandler : IHandler {
...
}
• RequestManager.AddHandler(handler)

8. Handler
WinAppDriver Components
HTTP
Server
Request
Manager
Session
Manager
Handler
UIA
Client API
WebDriver
Lang. Bindings

9. HTTP Server (WinAppDriver.Server)
• Based on System.Net.HttpListener
• Listen on http://+:4444/wd/hub/
• Configure firewall and Namespace Reservations
(elevated mode)
netsh http add urlacl url=http://+:4444/wd/hub/ user=Everyone

10. Request Manager (WinAppDriver.RequestManager)
• Manage endpoints (WinAppDriver.EndPoint) and handlers
(WinAppDriver.IHandler).
• Dispatch requests to corresponding handlers.
• Parse URL parameters and prepare the session object.
• Serialise returned object(s) to JSON.

11. Handlers (WinAppDriver.IHandler)
1. Parse request body, that is deserialising JSON
FindElementRequest request =
JsonConvert.DeserializeObject<FindElementRequest>(body);
2. Search for or manipulate UI elements using the UIA Client API.
3. Return a Dictionary or Data Transfer Object (DTO).
return new Dictionary<string, object> {
{ "sessionId", session.ID },
{ "status", 0 },
{ "value",
new Dictionary<string, int> {
{ "ELEMENT", id }
}
}
};

12. Session Manager (WinAppDriver.SessionManager)
• Manage sessions (WinAppDriver.Session).
• A session caches references to UI elements
(System.Windows.Automation.AutomationElement) for
subsequent interactions.

13. TODO
• Build system
• Solution file (.sln)
• Remove third-party assemblies from Git repo.
• Travis CI build (low priority)
• Exception handling, e.g., throw new ElementNotFoundException()
• Discover and register all handlers automatically.
• Download, install and uninstall app packages automatically.
• Implement remaining commands defined in the protocol. (logs, screenshots,
…)
• Fast reset - clear data without uninstalling the package

14. References
• Configuring HTTP and HTTPS - MSDN
• MSBuild
• P of EAA: Data Transfer Object