blockscout/apps/ethereum_jsonrpc/config/runtime/test.exs

import Config

variant =
  if is_nil(System.get_env("ETHEREUM_JSONRPC_VARIANT")) do
    "parity"
  else
    System.get_env("ETHEREUM_JSONRPC_VARIANT")
    |> String.split(".")
    |> List.last()
    |> String.downcase()
  end

Code.require_file("#{variant}.exs", "#{__DIR__}/../../../explorer/config/test")
Code.require_file("#{variant}.exs", "#{__DIR__}/../../../indexer/config/test")