Dynamically change connection string for UI tests

Question

I'm using WebAii library for UI testing - I want to test whether my component displays the same records as there are in database therefore I need to switch my application's connection string to point to the test database just for the time of running tests. What is the best way to do it? How to dynamically change the connection string prior to running the app? Thanks

Answer 1

Are you storing the connection string in the Web.config file? If so, I would deploy a new Web.config just before starting the test and then use the command line to send an IISRESET.

FYI, these are the kinds of questions we answer all day long on our public forum dedicated to WebAii.

Cody Telerik Technical Support

Answer 2

What kind of application is it? This is first probably an indication of not-well-factored code. Next, it is common to have a separate environment for testing code.

If you are, for example, deploying to ASP.NET with Visual Studio, you can use Web.config file transformations to set a different value when you deploy to e.g. test.contoso.com vs. www.contoso.com. The transformation syntax allows you to define a new connection string, or change an existing one from the base Web.config, when deploying a different configuration.

If you have a single environment, and control over it, you could probably write a couple of (Power)shell scripts to copy a web.config with "test" connection strings to your app root prior to the test. Then run a second script to reset the original web.config after the test is run.

If you have access to your deploy directory within the context you will be running your tests, you could even simply have a Web.test.config file included in your unit test project. In [AssemblyInitialize]:

1. File-copy _\\{your app server}{your app directory}\Web.config to \\{your app server}{your app directory}\Web.config.orig.
2. File-copy Web.test.config to \\{your app server}{your app directory}\Web.config.
3. Sleep for a few seconds?

Then do the reverse in [AssemblyCleanup].

Other strategies exist, too. You could build in an override to your application when in debug mode, that checks various things (special file, additional config, cookies, extra query string). Or you could have a Settings manager in your app that you can instrument in test setup when arranging your test (click through UI to change DB settings).

Very likely, however, you may get the best compounding rewards by factoring your code to reduce dependencies. Then you can write unit tests which stub/mock/fake the database. You can use code coverage tools to verify that you've tested specific scenarios, or to see that additional integration tests would be duplication of coverage at that point.