Nil value for fields using the source field option

[Matt Stubbs]

I've been testing the 2.0.0-alpha.1 version locally and believe I've confirmed a regression. A schema that uses a field with the source option returns nil for the field rather than restoring the field value. Here's an example test case:

defmodule Ecto.Adapters.DynamoDB.TestSchema.Moon do
  use Ecto.Schema
  @primary_key {:id, :binary_id, autogenerate: true}
  @foreign_key_type :binary_id

  schema "test_planet" do
    field :name, :string
    field :adjective, :string, source: :data1
  end
end

defmodule Ecto.Adapters.DynamoDB.SourceFieldTest do
  use ExUnit.Case
  import Ecto.Query

  setup_all do
    TestHelper.setup_all()

    on_exit(fn ->
      TestHelper.on_exit()
    end)
  end

  test "using a field with the source option" do
    alias Ecto.Adapters.DynamoDB.TestSchema.Moon

    changeset = Ecto.Changeset.change(%Moon{}, %{name: "Europa", adjective: "Europan"})
    {:ok, europa} = Ecto.Adapters.DynamoDB.TestRepo.insert(changeset)

    %Moon{adjective: adjective} = Ecto.Adapters.DynamoDB.TestRepo.get(Moon, europa.id)
    assert adjective == "Europan" 
  end
end

The assertion is expected to pass, but fails:

  1) test OK (Ecto.Adapters.DynamoDB.SourceFieldTest)
     test/source_field_test.exs:26
     Assertion with == failed
     code:  assert adjective == "Europan"
     left:  nil
     right: "Europan"
     stacktrace:
       test/source_field_test.exs:35: (test)

Any thoughts on what could be the cause?

[Darren]

Ah sorry - I realized that perhaps you're asking for a tip on where to start looking for the source of this problem yourself - probably the best place to start digging is execute/5 in the main module, lib/ecto_adapters_dynamodb.ex - check out the arguments that that function is receiving. I'd bet that the data is there, but it's just not being extracted correctly.

[Darren]

Terrific fix! I'll be cutting another alpha release shortly, which will include your work.

Your contributions to this project are much appreciated!