title: connectionStrings configSource in App.config not working
body: <p>I'm trying to separate my connection string from my <code>App.config</code>, and as you can't do transformations like with <code>Web.config</code>, I thought may I could use the <code>configSource</code> attribute to point to another config file with the connection string in, but it doesn't seem to be working.</p>
  
  <p>This works, <code>App.config</code>:</p>
  
  
  
  <pre class="lang-xml prettyprint-override"><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;configuration&gt;
    &lt;configSections&gt;
      &lt;section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=5.0.0.0, Culture=neutral, PublicKeyToken=*snip*" requirePermission="false" /&gt;
    &lt;/configSections&gt;
    &lt;entityFramework&gt;
      &lt;defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework"&gt;
        &lt;parameters&gt;
          &lt;parameter value="v11.0" /&gt;
        &lt;/parameters&gt;
      &lt;/defaultConnectionFactory&gt;
    &lt;/entityFramework&gt;
    &lt;connectionStrings&gt;
      &lt;add name="DefaultConnection"
        providerName="System.Data.SqlClient"
        connectionString="Server=*snip*" /&gt;
    &lt;/connectionStrings&gt;
  &lt;/configuration&gt;
  </code></pre>
  
  <p>But this doesn't, <code>App.config</code>:</p>
  
  <pre class="lang-xml prettyprint-override"><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;configuration&gt;
    &lt;configSections&gt;
      &lt;section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=5.0.0.0, Culture=neutral, PublicKeyToken=*snip*" requirePermission="false" /&gt;
    &lt;/configSections&gt;
    &lt;entityFramework&gt;
      &lt;defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework"&gt;
        &lt;parameters&gt;
          &lt;parameter value="v11.0" /&gt;
        &lt;/parameters&gt;
      &lt;/defaultConnectionFactory&gt;
    &lt;/entityFramework&gt;
    &lt;connectionStrings configSource="connections.config" /&gt;      
  &lt;/configuration&gt;
  </code></pre>
  
  <p><code>connections.config</code>:</p>
  
  <pre class="lang-xml prettyprint-override"><code>&lt;connectionStrings&gt;
      &lt;add name="DefaultConnection"
        providerName="System.Data.SqlClient"
        connectionString="*snip*" /&gt;
  &lt;/connectionStrings&gt;
  </code></pre>
  
  <p>I'm looking for the simplest of solutions.</p>
  
  <p>Any ideas?</p>