CODEWITHSUNDEEP
asp.netunit-testingvisual-studio-2015
WebDevGuy2
WebDevGuy2

Reputation: 1249

Unit Test Project: "No connection string could be found in the application config file"

I had an existing MVC5 web app. I just created a new Unit Test Project and added the following code....

using Microsoft.VisualStudio.TestTools.UnitTesting;
using SomethingApp.Services;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using SUT = SomethingApp.Services.ReportingServices; // SUT = System Under Test

namespace SomethingApp.Services.Tests
{
    [TestClass]
    public class GettingScoreForQuestionShould
    {
        [TestMethod]
        public void ReturnScoreWhenGivenValidData()
        {
            // Arrange
            int eventId = 39;
            int questionId = 271;
            decimal score; 

            // Act
            score = SUT.GetScoreForQuestion(eventId, questionId);

            // Assert
            Assert.AreEqual("80",score);
        }
    }
}

When the method GetScoreForQuestion runs in the normal web app it runs perfect. But, when I run it through the test method I'm getting this error...

Message: Test method SomethingApp.Services.Tests.GettingScoreForQuestionShould.ReturnScoreWhenGivenValidData threw exception: System.InvalidOperationException: No connection string named 'myDbContext' could be found in the application config file.

The error is, of course, coming from the method GetScoreForQuestion, which works fine in the normal web app.

I don't understand why I need to add an application config file and this config connection string to the test project. Seems like, since I'm calling the method in the MVC project, that this has the responsibility of making the connection and doing it's thing (which it's doing in the normal course of the app). Am I mistaking something?

And, I tried adding a new application.config file and the connection string to the unit test project, but then the test method won't show up anymore in the Test Explorer after build. Any suggestions? Thanks!

UPDATE ****

Here's the code for GetScoreForQuestion (the offending method, which works in the web app fine, but not when called thru the test method)....

public static decimal GetScoreForQuestion(int eventId, int ThingyQuestionId)
{
    // the following line fails with the connection issue
    var ThingyResults = Db.ThingyResults.Where(e => e.EventId == eventId && e.ThingyQuestionId == ThingyQuestionId)
        .AsNoTracking().ToList();
       :
       :
       :
}

Db is declared in the same class as...

public static class ReportingServices
{
    private static readonly ThingyContext Db = new ThingyContext();

Upvotes: 0

Views: 1795

Answers (2)

Hans Kesting
Hans Kesting

Reputation: 39283

When you are executing a unittest, that project is your running application. So that is where the configuration file is read from. And note that you need an app.config, not a web.config.

Upvotes: 2

ovation22
ovation22

Reputation: 731

It looks like you may be creating a new ThingyContext within your ReportingServices class. Look into injecting an Interface so that you can substitute a mock implementation for testing purposes.

Here's some links to help get you started:

https://romiller.com/2012/02/14/testing-with-a-fake-dbcontext/

https://ardalis.com/new-is-glue

Upvotes: 0

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