Populate IConfiguration for unit tests

Question

.NET Core configuration allows so many options to add values (environment variables, json files, command line args).

I just can\'t figure out and find an answer how

Answer 1

You can use MemoryConfigurationBuilderExtensions to provide it via a dictionary.

using Microsoft.Extensions.Configuration;

var myConfiguration = new Dictionary
{
    {"Key1", "Value1"},
    {"Nested:Key1", "NestedValue1"},
    {"Nested:Key2", "NestedValue2"}
};

var configuration = new ConfigurationBuilder()
    .AddInMemoryCollection(myConfiguration)
    .Build();

The equivalent JSON would be:

{
  "Key1": "Value1",
  "Nested": {
    "Key1": "NestedValue1",
    "Key2": "NestedValue2"
  }
}

The equivalent Environment Variables would be (assuming no prefix / case insensitive):

Key1=Value1
Nested__Key1=NestedValue1
Nested__Key2=NestedValue2