Mock IConfigurate in xUnit

If you want mock IConfiguration use following code:

public IConfiguration Configuration { get; }

var mockConfiguration = new Mock<IConfiguration>();
mockConfiguration.SetupGet(x => x[It.Is<string>(s => s == "CMCApiKey")]).Returns("test123");

Configuration = mockConfiguration.Object;

or copy secrets.json configuration file to output directory: projectName\bin\Debug\netcoreapp3.1 and then use following code in ContextFixture:

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

Config json file e.g. secrets.json:

{
  "CMCApiKey": "test123"
}