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Testing WPF applications

I am currently doing my write-up for my third year degree project. I created a system using C# which used a Microsoft Access as the back end database. The system does not connect to the internet, nor does it use the local network for any connectivity.
I am asking for the best method to test an application such as this, so that it is of sufficient testing.

You should impelement the Repository Pattern, which will abstract the database code so that you can test the business logic, while faking out the database calls.

I don't know what exactly you're looking for and how loosely coupled your application is, but in my case, most of the code (roughly 90%) is written so that it can be tested in unit tests, without any need to run the ui. The MVVM pattern is a good starter for that, since it forces you to move code out of your UI into separate classes like ViewModels, Commands, which can be unit tested.
That assures a lot already, and if you need to do automated UI testing, take a look at the Coded UI Tests available in Visual Studio 2010 (Premium and Ultimate only). They allow you to fully automate / simulate user interaction. In simulation, you can do what Justin proposed : detach your application from the database and work with a repository.
You have to keep in mind that in order to write really testable code, you have to design your code testable. In my experience it is next to impossible to write Unit Tests for code written without testing intent right from the start. The probably best thing you can do in that case is write integration tests.
But in order to give more clear advice, we need more input.
Cheers

Outside-in BDD (with Specflow)

I'm new to BDD, but I found it very interesting and want to develop my next project using BDD. After googling and watching screencasts I still have lots of questions about BDD in real life.
1. Declarative or Imperative scenarios?
Most of given-when-then scenarios I saw were written in terms of UI (imperative).
Scenario: Login
Given I am on the Login-page
When I enter 'AUser' in the textbox 'UserName'
And I enter 'APassword' in the textbox 'Password'
And I click the 'Login' button
Then I should see the following text 'You are logged in'
I found those tests extremely brittle and they tell nothing about business value of clicking on buttons. I think its nightmare to maintain. Why most of examples use imperative scenarios?
Scenario: Login (declarative)
Given I am not logged in
When I log in using valid credentials
Then I should be logged in
If you prefer declarative style, how do you describe such stuff like 'Home page' or 'Products page'?
Tips for writing good specifications
2. Exercise UI or not?
Most of steps implementations I saw used WatiN, White or something like that to implement scenarios from user point of view. Starting browser, clicking buttons. I think its extremely slow and brittle. Well, I can use something like Page object to make tests less brittle. But thats another amount of work. Especially for desktop applications with complex UI.
How do you implement scenarios in real-life projects - exercising UI, or via testing controllers/presenters?
Best way to apply BDD
3. Real database or not?
When Given part of scenario is implemented, often it needs some data to be in the system (e.g. some products for shop application). How do you implement that part - adding data to real database (full end-to-end testing), or providing repository stubs to controllers?
Waiting for experienced answers!
UPDATE: Added useful links on questions.

Declaritive is the proper way, IMO. If youre talking about page .aspx file names, you're doing it wrong. The purpose of the story is to facilitate communication between developers and non-develoeprs. Non-developers don't care about products.aspx, they care about a product listing. Your system does something the non-developers find value in. This is what you're trying to capture.
Well, the stories tell the high level features you need to implement. Its what your system must do. The only way to really tell if you've done this is to in fact exercise the UI. BDD SpecFlow stories to me don't replace unit tests, rather they're you're integration tests. If you break this, you've broken the value the business gets from your software. Unit tests are implementation details your users don't care about, and they only test each piece in isolation. That can't tell you if A and B actually work together all the time (in theory it should, in practice interesting [read: unexpected] things happen when you actually have the two parts playing with each other). Automated end to end tests can help with your QA as well. If a functional area breaks, you know about it, and they can spend their time in other areas of the application while you determine what broke the integration tests.
This is a tricky one. We've done a hybrid approach. We do use the database (integrate tests after all test the system functioning as one thing, rather than the individual components), but rather than resetting configurations all the time we use Deleporter to replace our repositories with Moqs when we need to. Seems to work ok, but there are certainly pros and cons either way. I think we're still largely figuring this out ourselves.

Edit: I found this article just now describing the concept of limiting yourself to talking only about specific domains to avoid brittle scenarios.
His main point is that the minimum number of domains you can talk about are the problem domain, and the solution domain. If you're talking about anything outside those two domains then you involve too many stakeholders, you introduce too much noise, and you make your scenarios brittle.
He also mentions an absolute "declarative" or "imperative" model being a myth. He talks about a cognative model called "chunking", saying that at any level of your abstraction, you can "chunk up" or "chunk down". This means you can get more explicit (how?) or more meta (what or why?). You chunk up from an imperative model by asking "what are we doing?" You chunk down by saying "how will we do this?" So I guess I wouldn't get too hung up on declarative vs imperative - it won't get you anywhere as far as this problem goes.
What will get you somewhere is figuring out which domains each term belongs in, possibly by identifying which stakeholder is the expert for the domain that term belongs in. Once you've identified all the domains, you can either pick related terms that are in one of the scenario's most prominent domains, or remove non-fitting statements entirely. If that isn't sufficient, you can split up, further specify, or move the scenario so it can satisfy these requirements.
BTW, he also uses the scenario of logging in on a UI, so you've got concrete guidance :)
Before Edit: (some of this still applies. The "DB or no DB" and "UI or no UI" questions are unrelated)
1 - Declarative or Imperative scenarios?
Declarative when you can, though imperative has some value (at some points in a project lifecycle).
Imperative is an easier way to think for testers and business analysts who aren't as familiar with information theory and design. It is also easier to think about earlier on in a project, before you've nailed down your problem domain and workflows. It can be useful for exploratory thinking.
Declarative is less subject to change over time. Since a GUI is the part of an application most subject to churn at a whim, this is extremely valuable. It is easier to think about once you've nailed down your problem domain and workflows, and are more focused on relational concepts. It is a more stable and more generally applicable model.
If you write test cases with a generic and declarative model, you could implement them using any combination of full app GUI automation, integration tests, or unit tests.
how do you describe such stuff like 'Home page' or 'Products page'?
I'm not sure I would at the base level of features and requirements. You might make sub-features and sub-requirements that describe implementation details, like specific UI workflows. If you're describing a piece of a UI, then you should be defining a UI feature/requirement.
2 - Exercise UI or not?
Both.
I think its extremely slow and brittle
Yes, it is. Perform every high level scenario/requirement with the UI and full DB integration, but don't exercise every single code path with end to end UI automation, and certainly not edge cases. If you do, you'll spend more time getting them working, and a lot less time actually testing your application.
You can architecture your application so you can do lower cost integration tests, including single-piece UI based tests. Unit tests are also valuable.
But the fewer integration tests you do, the more forehead-slapping bugs you're going to miss. It may be easier to write unit tests, and they will certainly be less brittle, but you'll be testing less of your application, by definition.
3 - Real database or not?
Both.
High level end-to-end integration tests must be done with the full system in place. This includes a real DB, running your tests with each system on a different server, etc.
The lower level you get, the more I advocate mock objects.
Unit tests should only test individual classes
Mid-level integration tests should avoid expensive, brittle, and impactful dependencies such as the file system, databases, the network, etc. Try to test the implementation of those brittle and impactful dependencies with unit tests and end-to-end tests only.

Instead of mentioning a page by name, describe what it represents, e.g.
Scenario: Customers logs in successfully
When I log in
Then I should see an overview of ACME's top selling products
You can test directly against underlying APIs or models, but the more you do this, the more you risk not catching an integration issue. One approach is to balance things with a small number of full-stack tests, and a larger number which test between two layers only.

Unit testing database application with business logic performed in the UI

I manage a rather large application (50k+ lines of code) by myself, and it manages some rather critical business actions. To describe the program simple, I would say it's a fancy UI with the ability to display and change data from the database, and it's managing around 1,000 rental units, and about 3k tenants and all the finances.
When I make changes, because it's so large of a code base, I sometimes break something somewhere else. I typically test it by going though the stuff I changed at the functional level (i.e. I run the program and work through the UI), but I can't test for every situation. That is why I want to get started with unit testing.
However, this isn't a true, three tier program with a database tier, a business tier, and a UI tier. A lot of the business logic is performed in the UI classes, and many things are done on events. To complicate things, everything is database driven, and I've not seen (so far) good suggestions on how to unit test database interactions.
How would be a good way to get started with unit testing for this application. Keep in mind. I've never done unit testing or TDD before. Should I rewrite it to remove the business logic from the UI classes (a lot of work)? Or is there a better way?

I would start by using some tool that would test the application through the UI. There are a number of tools that can be used to create test scripts that simulate the user clicking through the application.
I would also suggest that you start adding unit tests as you add pieces of new functionality. It is time consuming to create complete coverage once the appliction is developed, but if you do it incrementally then you distribute the effort.
We test database interactions by having a separate database that is used just for unit tests. In that way we have a static and controllable dataset so that requests and responses can be guaranteed. We then create c# code to simulate various scenarios. We use nUnit for this.

I'd highly recommend reading the article Working Effectively With Legacy Code. It describes a workable strategy for what you're trying to accomplish.

One option is this -- every time a bug comes up, write a test to help you find the bug and solve the problem. Make it such that the test will pass when the bug is fixed. Then, once the bug is resolved you have a tool that'll help you detect future changes that might impact the chunk of code you just fixed. Over time your test coverage will improve, and you can run your ever-growing test suite any time you make a potentially far-reaching change.

TDD implies that you build (and run) unit tests as you go along. For what you are trying to do - add unit tests after the fact - you may consider using something like Typemock (a commercial product).
Also, you may have built a system that does not lend itself to be unit tested, and in this case some (or a lot) of refactoring may be in order.

First, I would recommend reading a good book about unit testing, like The Art Of Unit Testing. In your case, it's a little late to perform Test Driven Development on your existing code, but if you want to write your unit tests around it, then here's what I would recommend:
Isolate the code you want to test into code libraries (if they're not already in libraries).
Write out the most common Use Case scenarios and translate them to an application that uses your code libraries.
Make sure your test program works as you expect it to.
Convert your test program into unit tests using a testing framework.
Get the green light. If not, then your unit tests are faulty (assuming your code libraries work) and you should do some debugging.
Increase the code and scenario coverage of your unit tests: What if you entered unexpected results?
Get the green light again. If the unit test fails, then it's likely that your code library does not support the extended scenario coverage, so it's refactoring time!
And for new code, I would suggest you try it using Test Driven Development.
Good luck (you'll need it!)

I'd recommend picking up the book Working Effectively with Legacy Code by Michael Feathers. This will show you many techniques for gradually increasing the test coverage in your codebase (and improving the design along the way).

Refactoring IS the better way. Even though the process is daunting you should definitely separate the presentation and business logic. You will not be able to write good unit tests against your biz logic until you make that separation. It's as simple as that.
In the refactoring process you will likely find bugs that you didn't even know existed and, by the end, be a much better programmer!
Also, once you refactor your code you'll notice that testing your db interactions will become much easier. You will be able write tests that perform actions like: "add new tenant" which will involve creating a mock tenant object and saving "him" to the db. For you next test you would write "GetTenant" and try and get that tenant that you just created from the db and into your in-memory representation... Then compare your first and second tenant to make sure all fields match values. Etc. etc.

I think it is always a good idea to separate your business logic from UI. There several benefits to this including easier unit testing and expandability. You might also want to refer to pattern based programming. Here is a link http://en.wikipedia.org/wiki/Design_pattern_(computer_science) that will help you understand design patterns.
One thing you could do for now, is within your UI classes isolate all the business logic and different business bases functions and than within each UI constructor or page_load have unit test calls that test each of the business functions. For improved readability you could apply #region tag around the business functions.
For your long term benefit, you should study design patterns. Pick a pattern that suits your project needs and redo your project using the design pattern.

It depends on the language you are using. But in general start with a simple testing class that uses some made up data(but still something 'real') to test your code with. Make it simulate what would happen in the app. If you are making a change in a particular part of the app write something that works before you change the code. Now since you have already written the code getting testing up is going to be quite a challenge when trying to test the entire app. I would suggest start small. But now as you write code, write unit testing first then write your code. You might also considering refactoring but I would weigh the costs of refactoring vs rewriting a little as you go unit testing along the way.

I haven't tried adding test for legacy applications since it is really a difficult chore. If you are planning to move some of the business logic out of the UI and in a separate layer, You may add your initial Test units here(refactoring and TDD). Doing so will give you an introduction for creating unit test for your system. It is really a lot of work but I guess it is the best place to start. Since it is a database driven application, I suggest that you use some mocking tools and DBunit tools while creating your test to simulate the database related issues.

There's no better way to get started unit testing than to try it - it doesn't take long, it's fun and addictive. But only if you're working on testable code.
However, if you try to learn unit testing by fixing an application like the one you've described all at once, you'll probably get frustrated and discouraged - and there's a good chance you'll just think unit testing is a waste of time.
I recommend downloading a unit testing framework, such as NUnit or XUnit.Net.
Most of these frameworks have online documentation that provides a brief introduction, like the NUnit Quick Start. Read that, then choose a simple, self-contained class that:
Has few or no dependencies on other classes - at least not on complex classes.
Has some behavior: a simple container with a bunch of properties won't really show you much about unit testing.
Try writing some tests to get good coverage on that class, then compile and run the tests.
Once you get the hang of that, start looking for opportunities to refactor your existing code, especially when adding new features or fixing bugs. When those refactorings lead to classes that meet the criteria above, write some tests for them. Once you get used to it, you can start by writing tests.

System Testing a desktop application

I've got a desktop application written in C# created using VS2008 Pro and unit tested with Nunit framework and Testdriven.net plugin for VS2008. I need to conduct system testing on the application.
I've previously done web based system tests using Bad Boy and Selenium plugin for Firefox, but I'm new to Visual Studio and C#.
I would appreciate if someone could share their advice regarding this.

System testing will likely need to be done via the UI. This gives you two options:
1) You can manually conduct the test cases by clicking on elements.
2) You can automate the test cases by programming against the UI. There are plenty of commercial tools to do this or you can use a programming framework like the Microsoft UI Automation Framework. These tend to use the accessibility APIs built into Windows to access your UI.
Whether you go the manual or automated route depends on how many times you will be running the tests. If you are just going to run them once or twice, don't spend the time automating. You will never earn it back. If you are going to run them often, automating can be very handy.
A word of caution: Automating the UI isn't hard, but it is very brittle. If the application is changing a lot, the tests will require a lot of maintenance.

As Thomas Owens commented on your question, first you must decide what kind of system testing you want to do. But assuming you want start with Functional System Tests. Prepare use cases you want to automate. Than you must find proper tool.
Just for start:
AtoIT – is not test atomization tool but it lets automate some tasks. So you could record/script use cases. Not really recommended, but can be done.
HP QuickTestPro – easily can be done with this tool via recording/scripting but it is expensive, so maybe not worth it for personal use.
IBM Robot – as HP QTP.
Powershell – you could write scripts in powershell and execute them. If you would use dedicated ide-like tools for powershell you could record test also. I did some web automation via powershell and it worked. With a bit of work probably you could script around your desktop app.
And the best would be to try different tools, and use one that suits you best. Try this link and this link.

System tests usually have use cases, end to end scenarios and other scripted functions that real people execute. These are the tests that don't lend themselves well to automation as they are asking your unit-tested cogs to work with each other. You might have great unit tests for your "nuts" and your "wrenches" but only a comprehensive system test will let you know if you have the right sized wrench for the nut at hand, how to select/return it from/to the drawer, etc.
In short - manual tests.

If you're willing to put money down, you could look at something like TestComplete.
Although I haven't really used it yet (our company just bought it), it seems quite nice. You can record clicks and keypresses and stuff, define success criteria, and it will replay the test for you later. It appears to be quite smart about UI changes - it remembers which button you clicked, not just the (x,y) of each click.
It's scriptable, or drag-and-drop programmable.
I'm not affiliated in any way, and this is not an endorsement, because I haven't really formed an opinion of it yet.

Perhaps NUnitForms could be useful for you?

Any BDD success stories out there?

Having written a small article on BDD, I got questions from people asking whether there are any cases of large-scale use of BDD (and specifically NBehave).
So my question goes to the community: do you have a project that used BDD successfully? If so, what benefits did you get, and what could have been better? Would you do BDD again? Would you recommend it to other people?

We've used somewhat of BDD at the code level in different scenarios (open source and ND projects).
Telling the view in MVC scenario, what kind of input to accept from user (DDD and Rule driven UI Validation in .NET)
result = view.GetData(
CustomerIs.Valid,
CustomerIs.From(AddressIs.Valid, AddressIs.In(Country.Russia)));
Telling the service layer, about the exception handling behavior (ActionPolicy is injected into the decorators):
var policy = ActionPolicy
.Handle<WebException>()
.Retry(3);
Using these approaches has immensely reduced code duplication, made the codebase more stable and flexible. Additionally, it made everything more simple, due to the logical encapsulation of complex details.

I was on a small team that used BDD on a website.
The way we used it was essentially TDD, but the tests are simply written as behaviors using a DSL. We did not get into large upfront design of behaviors, but we did create a large number of them, and used them exactly as you would tests.
As you might expect, it worked much as TDD, generally good. Phrasing the tests as behaviors was nice when interacting with the customers and made for a pretty decent document, but I kind of wish the behaviors were written in English and the tests programmed instead of trying to come up with some difficult intermediate language that doesn't fit either purpose perfectly.
It would still be BDD, just without this cute trick of trying to twist the language into a language delineated by a random_looking.set of_Punctuation rather_than simple.spaces, but that was only my grumpy-old-programmer attitude, everyone else was 100% happy with it.
The site is available and fully operational, so I'd call it a success: Have a look

I recently used the BDD style of GWT in a high-level requirements document. I didn't get any feedback about the GWT from the customer buy my boss said he liked it as it was very clear and easy to understand. Note he has no knowledge of BDD that I know of. I didn't put in user stories as this would probably have been a bit too airy fairy for people with a traditional waterfall background. Maybe I'll try putting in user stories next time.
By the way this was not a eye ball UI project. It was an integration project syncing data from a web service into a database. So it shows that GWT works even for non-"eye ball" UIs.

I've been using Context-Specification style on several projects (using MSpec) with great success. I am still trying to understand the real benefits of the Scenario style. The more I use the context-specification style, the more I like it, and the tighter my applications feel.