title: Mock get wrong connection String
body: <p>I am writing some tests. I am mocking entity framework. Yesterday worked everything correctly and I am almost sure I have not modified anything from yesterday.
  In the app.config of my test project I have this connection string</p>
  
  <pre><code>&lt;connectionStrings&gt;
    &lt;add name="PublicAreaContext"
        providerName="System.Data.SqlClient" connectionString="Server=.\SQLSERVER; ..." /&gt;
  &lt;/connectionStrings&gt;
  </code></pre>
  
  <p>Now I mock my entity framework context:</p>
  
  <pre><code>var mockContext = new Mock&lt;PublicAreaContext&gt;() { CallBase = true };
  ... // all my entities mocked
  mockContext.Setup(x =&gt; x.SaveChanges()).Returns(1);
  </code></pre>
  
  <p>Now when I start my test something goes wrong, and the context seems to be created using the wrong connection string</p>
  
  <p><a href="https://i.stack.imgur.com/JZ6Fr.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/JZ6Fr.png" alt="enter image description here"></a></p>
  
  <p>I do not understand where it takes that connection string... I looked for it in the solution SQLEXPRESS and I do not find anything. In my server (SQLSERVER) I can find a database called Castle.Proxy.PublicAreaContext. I think is the database created yesterday when everything worked.</p>
  
  <p>Can you tell me what can be the problem or how can I set correctly the connection string?</p>
  
  <p>Thank you</p>