Using Configuration files in .NET Core Unit Test Projects

So another thing I came across while converting the Integration tests for the Auth0.NET SDK to .NET Core was that I had to make use of configuration files which specify the settings so the Integration test can talk with Auth0.

Here are some of the basics which got it working for me…

Add the configuration file

First, add a client-secrets.json file to the Integration test project, e.g.

{
  "AUTH0_CLIENT_ID": "...",
  "AUTH0_CLIENT_SECRET": "..."
}

Configure the client-secrets.json file to be copied to the output directory by updating the buildOptions in the project.json file:

{
  "version": "1.0.0-*",

  "buildOptions": {
    "copyToOutput": {
      "include": [
        "client-secrets.json"
      ]
    }
  },

  "dependencies": {
    "..."
  },

  "testRunner": "nunit",

  "frameworks": {
    "net461": {}
  }}

Include the .NET Core Configuration NuGet package

Include the JSON Configuration file NuGet package (Microsoft.Extensions.Configuration.Json) in your project.json

{
  "version": "1.0.0-*",

  "buildOptions": {
    "copyToOutput": {
      "include": [
        "client-secrets.json"
      ]
    }
  },

  "dependencies": {
    "...",
    "Microsoft.Extensions.Configuration.Json": "1.0.0"
  },

  "testRunner": "nunit",

  "frameworks": {
    "net461": {}
  }
}

Be sure to run dotnet restore after you have added the package.

Use the configuration in your unit tests

You can now use the configuration file in your unit tests by using the ConfigurationBuilder class:

var config = new ConfigurationBuilder()
    .AddJsonFile("client-secrets.json")
    .Build();

And then access any configuration value:

var clientId = config["AUTH0_CLIENT_ID"]

You can read more about how configuration works in .NET Core projects in the ASP.NET Core Configuration documentation