CODEWITHSUNDEEP
c#
azamsharp
azamsharp

Reputation: 20066

ConfigurationManager ConnectionString Throwing Error and returning null

I am totally stunned as why one of my unit tests is failing. It is a simple test to see if the correct connectionstring is returned. My App.config looks like this: 

<?xml version="1.0" encoding="utf-8"?>
<configuration>
   <system.web>
      <compilation defaultLanguage="c#" debug="true" />
   </system.web>
   <connectionStrings>
      <add name="DbConnectionString" connectionString="Test_HighOnCoding_Db" />
   </connectionStrings>
</configuration>

And here is my simple unit test which always throws null exception: 

[TestFixture]
public class when_retrieving_database_name_from_config
{
    [Test]
    public void should_get_the_correct_database_name()
    {
       var dbName = ConfigurationManager.ConnectionStrings["DbConnectionString"].ConnectionString;

       // dbName is always null 

       Assert.AreEqual("Test_HighOnCoding_Db",dbName); 
    }
 }

Upvotes: 1

Views: 3273

Answers (3)

majikandy
majikandy

Reputation: 11

It is a simple fix - put the app.config in your test project.

Because you are running from a test, the app.config needs to be in your test project, and NOT with your actual program project.

When executing your test, the context of the running application is from your test assembly, so ConfigurationManager.ConnectionStrings will be looking ONLY in your test project bin folder for YourTestAssembly.dll.config (which is auto generated from your app.config in you test project folder).

Upvotes: 1

k3b
k3b

Reputation: 14755

if your testdll is MyTests.dll your app.config in that sub-projet will become MyTests.dll.config. Unfortunately nunit wants "MyTests.config" (without the ".dll.")

to solve this issue

  • create a nunit-project for "MyTests"
    • open nunit-gui
    • create a new nunit project "MyTests.nunit" in the bin folder
    • add MyTests.dll to MyTests.nunit
    • save the nunit project.
    • exit nunit
  • add "MyTests.nunit" to your solution
    • copy "MyTests.nunit" to the project source. make shure that settings are
    • buildaction = none
    • copy to Ouptut Dir = always
  • create a configfile "MyTests.config" for "MyTests.nunit"
    • under project settings/build events/PostBildEventCommandLine add
    • copy $(ProjectDir)\app.config $(TargetDir)\$(TargetName).config

now you can run your unittest by opening "MyTests.nunit"

Upvotes: 0

Andrew Barber
Andrew Barber

Reputation: 40150

My original answer does not apply per your comment below.

One thing I'll suggest checking, then; Is your app.config file being moved into the directory with your program, and being renamed to the same as the program, with .config added?

So, program.exe has program.exe.config as the config file?`

It looks like you have a Web application here; if so, your configuration file should be web.config rather than app.config. Then, you should be using the WebConfigurationManager from the System.Web.Configuration namespace.

Upvotes: 5

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