Ecto.Repo.update! is successful but returns changeset instead of struct, is it a bug or missing doc?

Hey @stoic.alchemist can you show code that exhibits this behavior, and the IO.inspect output of the result? I have never seen this myself.

Sure thing, can’t show real code but I’ll emulate what’s happening:

iex> current_struct = %MyApp.MyModel{ key1: "value1"}
iex> updated_struct = 
         current_struct
         |> Ecto.Changeset.change(key: "value2")
         |> Ecto.Repo.update!
         |> IO.inspect

#Ecto.Changeset<
  action: nil,
  changes: %{key: "value2"},
  errors: [],
  data: #MyApp.MyModel<>,
  valid?: true
>

Please let me know if this is good enough, this is just a simplification of what’s happening, the real code goes around to a bunch of files (I’m also skipping the Model definition and such, I don’t think it’s important but I may be wrong)

Hey @stoic.alchemist is Ecto.Repo.update! a typo? That function is not callable directly. Not being able to show real code is definitely going to be a bit tricky.

If you can’t show your code, can you show an example that reproduces this behavior?

You are not supposed to call Ecto.Repo directly, you have to derive it via a macro in your own project. Then you use it like so: MyApp.Repo.update!.

Most definitely, we do have our own Repo definition, I’ll try to show as much as I can:
Repo definition:

defmodule MyApp.Repo do
  use Ecto.Repo,
    otp_app: :my_app,
    adapter: Ecto.Adapters.Postgres
end

Model definition:

defmodule MyApp.MyModel do
  use Ecto.Schema
  import Ecto.Changeset
  alias MyApp.MyModel
  require Ecto.Query

  schema "my_models" do
    field :key, :string
    @timestamps_opts [type: :utc_datetime_usec]
    timestamps()
  end

  @fields [
    :key
  ]
 # A bunch of methods, around 200 lines or so
end

Now the Model it’s already initialized somewhere in the code:

# Somewhere inside a GenServer
my_model_struct
|> Ecto.Changeset.change(key: "value2")
|> MyApp.Repo.update!
|> IO.inspect() # Added to debug

This results in a:

#Ecto.Changeset<
  action: nil,
  changes: %{key: "value2"},
  errors: [],
  data: #MyApp.MyModel<>,
  valid?: true
>

Being that I’m doing the upgrade I thought this was a change in behavior but the docs say otherwise

Ok, I found the reason why… sorry for all the fuzz… tests are failing because the unit test file has a setup to use a “fake” Repo that returns the given data, which in this case is an Ecto.Changeset, so… sorry for the noise

The docs indicate that this shouldn’t be possible, the return type of Ecto.Repo — Ecto v3.14.0 is Ecto.Schema.t(). Without code we can run this is pretty tricky to sort out, I’ve not seen anything like that before.

That’s a pretty weird and IMO unproductive test setup. I recommend you remove that fake repo.

Yes, I agree, I’ll figure out why that’s there and remove it if it’s not needed, this can hide bugs (or in this case waste time searching for not-bugs )