MVC Unit Testing with Linq to Sql

Question

I have a controller that is working in my site but failing during unit testing. It is pretty simple and depends on Linq to Sql to return a collection of JSON objects.

The Test fails because the DataContext can't find the connection string when called from outside the MVC project.

I had a look in the auto generated code:

public DC():
            base(global::System.Configuration.ConfigurationManager.ConnectionStrings["myConnectionString"].ConnectionString, mappingSource)
    {
        OnCreated();
    }

The web project can find the "myConnectionString" entry in web.config, but the test project can't find it. The error message I got was:

Test method MyMVCApp.Controllers.HomeControllerTest.IndexShouldReturnIssues threw exception:  System.NullReferenceException: Object reference not set to an instance of an object..

I don't want to pass another connection string in from my unit tests because I want to test that the connection string in the web.config works.

Thanks, John

Look at this answer to see how to effectively and succesfully test with LINQ to SQL: stackoverflow.com/questions/4128640/… — Steven
– Steven, Commented Nov 9, 2010 at 20:29

tvanfosson · Accepted Answer · 2009-10-02 16:26:04Z

1

Add the connection string to the app.config file in your unit test project.

FWIW, I don't actually use a real database in my unit tests (although, I do in integration tests). I wrote about a LINQ-to-SQL implementation that allows mocking on my blog awhile back if you are interested in more info.

answered Oct 2, 2009 at 16:26

tvanfosson

534k102 gold badges703 silver badges801 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

John Hoge Over a year ago

I guess that would work, but I really want to test that the connection string in my web project works, so I guess you could call this an integration test. I wouldn't want to have a situation where the connection string is correct in the test but bad in the site.

Collectives™ on Stack Overflow

MVC Unit Testing with Linq to Sql

1 Answer 1

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related