I was working on a new .NET Core Unit/Integration Test project in a solution using Visual Studio and need to load some setting from the configuration. Naturally I wanted to use the same setup for retrieving those settings as in the real project, so I added a new file appsettings.json. Next up I wanted to add appsettings.Development.json just like we use in normal projects. Somehow I expected it to be nested beneath appsettings.json, like in the normal project. Of course, it didn’t 😄. While searching for a solution I noticed a lot of screenshots with the same issue: the files where not nested. Here is how to fix it.

The solution

The solution is updating your csproj file with a (new) item group that indicates the behavior you want:

 <ItemGroup>
    <None Update="appsettings.Development.json">
      <DependentUpon>appsettings.json</DependentUpon>
    </None>
  </ItemGroup>

With this you tell Visual Studio how you want this file to be displayed!

Visual Studio Code

Note: unfortunately the solution above will not work for Visual Studio code! For adding the same setup in Visual Studio Code you need to add the following to your .vscode/settings.json file:

"explorer.fileNesting.enabled": true,
    "explorer.fileNesting.patterns": {
        "appsettings.json": "appSettings.*.json"
    },