Add repro test for array expressions with custom types

priv/resource_snapshots/test_repo/rsvps/20251002180954.json

@@ -0,0 +1,43 @@
+{
+  "attributes": [
+    {
+      "allow_nil?": false,
+      "default": "fragment(\"gen_random_uuid()\")",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": true,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "id",
+      "type": "uuid"
+    },
+    {
+      "allow_nil?": false,
+      "default": "0",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "response",
+      "type": "integer"
+    }
+  ],
+  "base_filter": null,
+  "check_constraints": [],
+  "custom_indexes": [],
+  "custom_statements": [],
+  "has_create_action": true,
+  "hash": "8ADC3A631361A18B1B9A2070D5E8477428EDE39DE3B43FA5FF8E50CE7710B9E5",
+  "identities": [],
+  "multitenancy": {
+    "attribute": null,
+    "global": null,
+    "strategy": null
+  },
+  "repo": "Elixir.AshPostgres.TestRepo",
+  "schema": null,
+  "table": "rsvps"
+}

priv/test_repo/migrations/20251002180954_migrate_resources62.exs

@@ -0,0 +1,20 @@
+defmodule AshPostgres.TestRepo.Migrations.MigrateResources62 do
+  @moduledoc """
+  Updates resources based on their most recent snapshots.
+
+  This file was autogenerated with `mix ash_postgres.generate_migrations`
+  """
+
+  use Ecto.Migration
+
+  def up do
+    create table(:rsvps, primary_key: false) do
+      add(:id, :uuid, null: false, default: fragment("gen_random_uuid()"), primary_key: true)
+      add(:response, :integer, null: false, default: 0)
+    end
+  end
+
+  def down do
+    drop(table(:rsvps))
+  end
+end

test/support/domain.ex

@@ -53,6 +53,7 @@ defmodule AshPostgres.Test.Domain do
     resource(AshPostgres.Test.Order)
     resource(AshPostgres.Test.Chat)
     resource(AshPostgres.Test.Message)
+    resource(AshPostgres.Test.RSVP)
   end
 
   authorization do

test/support/resources/rsvp.ex

@@ -0,0 +1,42 @@
+defmodule AshPostgres.Test.RSVP do
+  @moduledoc false
+  use Ash.Resource,
+    domain: AshPostgres.Test.Domain,
+    data_layer: AshPostgres.DataLayer
+
+  postgres do
+    table "rsvps"
+    repo AshPostgres.TestRepo
+  end
+
+  actions do
+    default_accept(:*)
+    defaults([:create, :read, :update, :destroy])
+
+    # Uses an expression with an array of atoms for a custom type backed by integers.
+    update :clear_response do
+      change(
+        atomic_update(
+          :response,
+          expr(
+            if response in [:accepted, :declined] do
+              :awaiting
+            else
+              response
+            end
+          )
+        )
+      )
+    end
+  end
+
+  attributes do
+    uuid_primary_key(:id)
+
+    attribute(:response, AshPostgres.Test.Types.Response,
+      allow_nil?: false,
+      public?: true,
+      default: 0
+    )
+  end
+end

test/support/types/response.ex

@@ -0,0 +1,75 @@
+defmodule AshPostgres.Test.Types.Response do
+  @moduledoc false
+  use Ash.Type
+  use AshPostgres.Type
+  require Ash.Expr
+
+  @atoms_to_ints %{accepted: 1, declined: 2, awaiting: 0}
+  @ints_to_atoms Map.new(@atoms_to_ints, fn {k, v} -> {v, k} end)
+  @atom_values Map.keys(@atoms_to_ints)
+  @string_values Enum.map(@atom_values, &to_string/1)
+
+  @impl Ash.Type
+  def storage_type, do: :integer
+
+  @impl Ash.Type
+  def cast_input(nil, _), do: {:ok, nil}
+
+  def cast_input(value, _) when value in @atom_values, do: {:ok, value}
+  def cast_input(value, _) when value in @string_values, do: {:ok, String.to_existing_atom(value)}
+
+  def cast_input(integer, _) when is_integer(integer),
+    do: Map.fetch(@ints_to_atoms, integer)
+
+  def cast_input(_, _), do: :error
+
+  @impl Ash.Type
+  def matches_type?(value, _) when is_atom(value) and value in @atom_values, do: true
+  def matches_type?(_, _), do: false
+
+  @impl Ash.Type
+  def cast_stored(nil, _), do: {:ok, nil}
+  def cast_stored(integer, _) when is_integer(integer), do: Map.fetch(@ints_to_atoms, integer)
+  def cast_stored(_, _), do: :error
+
+  @impl Ash.Type
+  def dump_to_native(nil, _), do: {:ok, nil}
+  def dump_to_native(atom, _) when is_atom(atom), do: Map.fetch(@atoms_to_ints, atom)
+  def dump_to_native(_, _), do: :error
+
+  @impl Ash.Type
+  def cast_atomic(new_value, constraints) do
+    if Ash.Expr.expr?(new_value) do
+      {:atomic, new_value}
+    else
+      case cast_input(new_value, constraints) do
+        {:ok, value} -> {:atomic, value}
+        {:error, error} -> {:error, error}
+      end
+    end
+  end
+
+  @impl Ash.Type
+  def apply_atomic_constraints(new_value, _constraints) do
+    {:ok,
+     Ash.Expr.expr(
+       if ^new_value in ^@atom_values do
+         ^new_value
+       else
+         error(
+           Ash.Error.Changes.InvalidChanges,
+           message: "must be one of %{values}",
+           vars: %{values: ^Enum.join(@atom_values, ", ")}
+         )
+       end
+     )}
+  end
+
+  @impl AshPostgres.Type
+  def value_to_postgres_default(_, _, value) do
+    case Map.fetch(@atoms_to_ints, value) do
+      {:ok, integer} -> {:ok, Integer.to_string(integer)}
+      :error -> :error
+    end
+  end
+end

test/type_test.exs

@@ -1,6 +1,7 @@
 defmodule AshPostgres.Test.TypeTest do
   use AshPostgres.RepoCase, async: false
   alias AshPostgres.Test.Post
+  alias AshPostgres.Test.RSVP
 
   require Ash.Query
 
@@ -107,4 +108,12 @@
     post = Ash.Query.for_read(Post, :with_version_check, version: 1) |> Ash.read!()
     refute is_nil(post)
   end
+
+  test "array expressions work with custom types that map atoms to integers" do
+    rsvp = RSVP |> Ash.Changeset.for_create(:create, %{response: :accepted}) |> Ash.create!()
+
+    updated = rsvp |> Ash.Changeset.for_update(:clear_response, %{}) |> Ash.update!()
+
+    assert updated.response == :awaiting
+  end
 end