phoenix_sync

defmodule Phoenix.Sync.Sandbox.Postgres do
  defmacro __using__(_opts) do
    quote do
      require Phoenix.Sync.Sandbox.Postgres
    end
  end

  @doc """
  Replace hard-coded references to `Ecto.Adapters.Postgres` with this macro to
  enable the `Phoenix.Sync.Sandbox` in test mode.

  In development or production environments the repo will use the standard
  Postgres adapter directly, only if `Mix.env() == :test` (see below) will it
  use the sandbox adapter shim.

  Example:

      defmodule MyApp.Repo do
        use Phoenix.Sync.Sandbox.Postgres

        use Ecto.Repo,
          otp_app: :my_app,
          adapter: Phoenix.Sync.Sandbox.Postgres.adapter()
      end

  ### Custom environments

  If you want to enable the sandbox adapter in different environments, you can
  use your own evaluation logic:

      defmodule MyApp.Repo do
        use Phoenix.Sync.Sandbox.Postgres

        use Ecto.Repo,
          otp_app: :my_app,
          adapter: Phoenix.Sync.Sandbox.Postgres.adapter(Mix.env() in [:test, :special])
      end

  > #### Warning {: .warning}
  >
  > The expression passed to `adapter/1` will be evaluated at **compile time**,
  > not run-time so only use expressions that can be evaluated at then (this
  > includes the various `Mix` functions).
  """
  defmacro adapter(expr \\ Mix.env() == :test) do
    {enable_sandbox?, _binding} = Code.eval_quoted(expr, binding())

    if enable_sandbox?,
      do: Phoenix.Sync.Sandbox.Postgres.Adapter,
      else: Ecto.Adapters.Postgres
  end
end