feat: add support for :identity types (#715)

Author: Jatanasio

lib/migration_generator/migration_generator.ex

@@ -530,7 +530,7 @@ defmodule AshPostgres.MigrationGenerator do
                 end)
 
               operations
-              |> organize_operations
+              |> organize_operations()
               |> build_up_and_down()
               |> migration(repo, opts, tenant?, run_without_transaction?, split_index)
             end)

lib/migration_generator/operation.ex

@@ -77,13 +77,11 @@ defmodule AshPostgres.MigrationGenerator.Operation do
       :bigint
     end
 
-    def reference_type(%{type: :integer, default: "nil", generated?: true}, _) do
-      ":bigserial"
-    end
+    def reference_type(%{type: :identity}, _), do: ":identity"
 
-    def reference_type(%{type: type}, _) do
-      type
-    end
+    def reference_type(%{type: :integer, default: "nil", generated?: true}, _), do: ":bigserial"
+
+    def reference_type(%{type: type}, _), do: type
 
     def with_match(reference, source_attribute \\ nil)
 
@@ -489,6 +487,16 @@ defmodule AshPostgres.MigrationGenerator.Operation do
       |> join()
     end
 
+    def up(%{attribute: %{type: :identity} = attribute}) do
+      [
+        "add #{inspect(attribute.source)}",
+        ":identity",
+        maybe_add_null(attribute.allow_nil?),
+        maybe_add_primary_key(attribute.primary_key?)
+      ]
+      |> join()
+    end
+
     def up(%{attribute: %{type: :bigint, default: "nil", generated?: true} = attribute}) do
       [
         "add #{inspect(attribute.source)}",
@@ -659,10 +667,14 @@ defmodule AshPostgres.MigrationGenerator.Operation do
              Map.get(old_attribute, :references) != Map.get(attribute, :references) do
           reference(multitenancy, attribute, schema)
         else
-          if attribute.type == :bigint and attribute.default == "nil" and attribute.generated? do
-            ":bigserial"
+          if attribute.type == :identity do
+            ":identity"
           else
-            inspect(attribute.type)
+            if attribute.type == :bigint and attribute.default == "nil" and attribute.generated? do
+              ":bigserial"
+            else
+              inspect(attribute.type)
+            end
           end
         end
 

lib/resource_generator/spec.ex

@@ -956,6 +956,7 @@ defmodule AshPostgres.ResourceGenerator.Spec do
 
   defp type("bigint"), do: {:ok, :integer}
   defp type("bigserial"), do: {:ok, :integer}
+  defp type("identity"), do: {:ok, :identity}
   defp type("boolean"), do: {:ok, :boolean}
   defp type("bytea"), do: {:ok, :binary}
   defp type("varchar"), do: {:ok, :string}

test/filter_test.exs

@@ -1128,13 +1128,13 @@ defmodule AshPostgres.FilterTest do
            |> Ash.Query.for_read(:read)
            |> Ash.Query.filter(first_member.id != ^cm2.id)
            |> Ash.read!()
-           |> length == 4
+           |> length() == 4
 
     assert Channel
            |> Ash.Query.for_read(:read)
            |> Ash.Query.filter(first_member.id == ^cm2.id)
            |> Ash.read!()
-           |> length == 1
+           |> length() == 1
   end
 
   test "using exists with from_many?" do
@@ -1149,13 +1149,13 @@ defmodule AshPostgres.FilterTest do
            |> Ash.Query.for_read(:read)
            |> Ash.Query.filter(exists(first_member, id == ^cm2.id))
            |> Ash.read!()
-           |> length == 0
+           |> length() == 0
 
     assert Channel
            |> Ash.Query.for_read(:read)
            |> Ash.Query.filter(exists(first_member, id == ^cm1.id))
            |> Ash.read!()
-           |> length == 1
+           |> length() == 1
   end
 
   test "using exists with has_many with limit" do

test/migration_generator_test.exs

@@ -1863,6 +1863,62 @@ defmodule AshPostgres.MigrationGeneratorTest do
     end
   end
 
+  describe "migration_types identity" do
+    setup %{snapshot_path: snapshot_path, migration_path: migration_path} do
+      defresource(IdentityPost) do
+        postgres do
+          table "identity_posts"
+          repo(AshPostgres.TestRepo)
+          migration_types(id: :identity, sequence_id: :identity)
+        end
+
+        actions do
+          defaults([:create, :read, :update, :destroy])
+        end
+
+        attributes do
+          integer_primary_key(:id)
+
+          attribute(:sequence_id, :integer,
+            generated?: true,
+            allow_nil?: false,
+            public?: true
+          )
+
+          attribute(:title, :string, public?: true)
+        end
+      end
+
+      defmodule IdentityDomain do
+        use Ash.Domain
+
+        resources do
+          resource(IdentityPost)
+        end
+      end
+
+      AshPostgres.MigrationGenerator.generate(IdentityDomain,
+        snapshot_path: snapshot_path,
+        migration_path: migration_path,
+        quiet: true,
+        format: false,
+        auto_name: true
+      )
+
+      :ok
+    end
+
+    test "uses :identity when set in migration_types", %{migration_path: migration_path} do
+      assert [file] =
+               Path.wildcard("#{migration_path}/**/*_migrate_resources*.exs")
+               |> Enum.reject(&String.contains?(&1, "extensions"))
+
+      file_contents = File.read!(file)
+      assert file_contents =~ ~S[add :id, :identity, null: false, primary_key: true]
+      assert file_contents =~ ~S[add :sequence_id, :identity, null: false]
+    end
+  end
+
   describe "--check option" do
     setup do
       defposts do