test: Add distinct sort tests (#605)

* Add support for sorting with filtered relationship tests

* Add filter relationship tests

Author: ken-kost

priv/resource_snapshots/test_repo/post_tags/20250810102512.json

@@ -0,0 +1,100 @@
+{
+  "attributes": [
+    {
+      "allow_nil?": false,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": true,
+      "references": {
+        "deferrable": false,
+        "destination_attribute": "id",
+        "destination_attribute_default": null,
+        "destination_attribute_generated": null,
+        "index?": false,
+        "match_type": null,
+        "match_with": null,
+        "multitenancy": {
+          "attribute": null,
+          "global": null,
+          "strategy": null
+        },
+        "name": "post_tags_post_id_fkey",
+        "on_delete": null,
+        "on_update": null,
+        "primary_key?": true,
+        "schema": "public",
+        "table": "posts"
+      },
+      "scale": null,
+      "size": null,
+      "source": "post_id",
+      "type": "uuid"
+    },
+    {
+      "allow_nil?": false,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": true,
+      "references": {
+        "deferrable": false,
+        "destination_attribute": "id",
+        "destination_attribute_default": null,
+        "destination_attribute_generated": null,
+        "index?": false,
+        "match_type": null,
+        "match_with": null,
+        "multitenancy": {
+          "attribute": null,
+          "global": null,
+          "strategy": null
+        },
+        "name": "post_tags_tag_id_fkey",
+        "on_delete": null,
+        "on_update": null,
+        "primary_key?": true,
+        "schema": "public",
+        "table": "tags"
+      },
+      "scale": null,
+      "size": null,
+      "source": "tag_id",
+      "type": "uuid"
+    }
+  ],
+  "base_filter": null,
+  "check_constraints": [],
+  "custom_indexes": [],
+  "custom_statements": [],
+  "has_create_action": true,
+  "hash": "BC5024D4E17EDD4ABDD0EF3D81EE5932FB63DF036E1BA81989D21A12496FE4A9",
+  "identities": [
+    {
+      "all_tenants?": false,
+      "base_filter": null,
+      "index_name": "post_tags_unique_post_tag_index",
+      "keys": [
+        {
+          "type": "atom",
+          "value": "post_id"
+        },
+        {
+          "type": "atom",
+          "value": "tag_id"
+        }
+      ],
+      "name": "unique_post_tag",
+      "nils_distinct?": true,
+      "where": null
+    }
+  ],
+  "multitenancy": {
+    "attribute": null,
+    "global": null,
+    "strategy": null
+  },
+  "repo": "Elixir.AshPostgres.TestRepo",
+  "schema": null,
+  "table": "post_tags"
+}

priv/resource_snapshots/test_repo/tags/20250810102512.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": "importance",
+      "type": "bigint"
+    }
+  ],
+  "base_filter": null,
+  "check_constraints": [],
+  "custom_indexes": [],
+  "custom_statements": [],
+  "has_create_action": true,
+  "hash": "9770C678D127B7ECA9FEAF174305101CC111417744E5D5712CD7F0A865D9877A",
+  "identities": [],
+  "multitenancy": {
+    "attribute": null,
+    "global": null,
+    "strategy": null
+  },
+  "repo": "Elixir.AshPostgres.TestRepo",
+  "schema": null,
+  "table": "tags"
+}

priv/test_repo/migrations/20250810102512_migrate_resources57.exs

@@ -0,0 +1,58 @@
+defmodule AshPostgres.TestRepo.Migrations.MigrateResources57 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(:tags, primary_key: false) do
+      add(:id, :uuid, null: false, default: fragment("gen_random_uuid()"), primary_key: true)
+      add(:importance, :bigint, null: false, default: 0)
+    end
+
+    create table(:post_tags, primary_key: false) do
+      add(
+        :post_id,
+        references(:posts,
+          column: :id,
+          name: "post_tags_post_id_fkey",
+          type: :uuid,
+          prefix: "public"
+        ),
+        primary_key: true,
+        null: false
+      )
+
+      add(
+        :tag_id,
+        references(:tags,
+          column: :id,
+          name: "post_tags_tag_id_fkey",
+          type: :uuid,
+          prefix: "public"
+        ),
+        primary_key: true,
+        null: false
+      )
+    end
+
+    create(unique_index(:post_tags, [:post_id, :tag_id], name: "post_tags_unique_post_tag_index"))
+  end
+
+  def down do
+    drop_if_exists(
+      unique_index(:post_tags, [:post_id, :tag_id], name: "post_tags_unique_post_tag_index")
+    )
+
+    drop(constraint(:post_tags, "post_tags_post_id_fkey"))
+
+    drop(constraint(:post_tags, "post_tags_tag_id_fkey"))
+
+    drop(table(:post_tags))
+
+    drop(table(:tags))
+  end
+end

test/calculation_test.exs

@@ -1,7 +1,19 @@
 defmodule AshPostgres.CalculationTest do
   alias AshPostgres.Test.RecordTempEntity
   use AshPostgres.RepoCase, async: false
-  alias AshPostgres.Test.{Account, Author, Comedian, Comment, Post, Record, TempEntity, User}
+
+  alias AshPostgres.Test.{
+    Account,
+    Author,
+    Comedian,
+    Comment,
+    Post,
+    PostTag,
+    Record,
+    Tag,
+    TempEntity,
+    User
+  }
 
   require Ash.Query
   import Ash.Expr
@@ -1045,4 +1057,23 @@ defmodule AshPostgres.CalculationTest do
              |> Ash.Query.sort("posts_with_matching_title.relevance_score")
              |> Ash.read!()
   end
+
+  test "sorting with filtered relationship by calculated field" do
+    tag = Ash.Changeset.for_create(Tag, :create) |> Ash.create!()
+    scores = [0, 3, 111, 22, 9, 4, 2, 33, 10]
+
+    scores
+    |> Enum.each(fn score ->
+      post =
+        Ash.Changeset.for_create(Post, :create, %{score: score})
+        |> Ash.create!()
+
+      Ash.Changeset.for_create(PostTag, :create, post_id: post.id, tag_id: tag.id)
+      |> Ash.create!()
+    end)
+
+    post_with_highest_score = Ash.load!(tag, :post_with_highest_score).post_with_highest_score
+    highest_score = hd(Enum.sort(scores, :desc))
+    assert post_with_highest_score.score == highest_score
+  end
 end

test/sort_test.exs

@@ -1,7 +1,7 @@
 defmodule AshPostgres.SortTest do
   @moduledoc false
   use AshPostgres.RepoCase, async: false
-  alias AshPostgres.Test.{Comment, Post, PostLink, PostView}
+  alias AshPostgres.Test.{Comment, Post, PostLink, PostTag, PostView, Tag}
 
   require Ash.Query
   require Ash.Sort
@@ -267,4 +267,26 @@ defmodule AshPostgres.SortTest do
                |> Ash.Query.sort({Ash.Sort.expr_sort(views.time, :datetime), :desc}, title: :asc)
              )
   end
+
+  test "sorting with filtered relationship" do
+    tag = Ash.Changeset.for_create(Tag, :create) |> Ash.create!()
+    dates = [~D[2025-01-03], ~D[2025-01-05], ~D[2025-01-01], ~D[2025-01-10], ~D[2025-01-02]]
+
+    dates
+    |> Enum.each(fn date ->
+      {:ok, datetime} = DateTime.new(date, ~T[00:00:00])
+
+      post =
+        Ash.Changeset.for_create(Post, :create, %{created_at: datetime})
+        |> Ash.create!()
+
+      Ash.Changeset.for_create(PostTag, :create, post_id: post.id, tag_id: tag.id)
+      |> Ash.create!()
+    end)
+
+    latest_post = Ash.load!(tag, :latest_post).latest_post
+    expected_date = hd(Enum.sort(dates, :desc))
+
+    assert DateTime.to_date(latest_post.created_at) == expected_date
+  end
 end

test/support/domain.ex

@@ -42,6 +42,8 @@ defmodule AshPostgres.Test.Domain do
     resource(AshPostgres.Test.CSV)
     resource(AshPostgres.Test.StandupClub)
     resource(AshPostgres.Test.Punchline)
+    resource(AshPostgres.Test.Tag)
+    resource(AshPostgres.Test.PostTag)
   end
 
   authorization do

test/support/resources/post.ex

@@ -777,6 +777,12 @@ defmodule AshPostgres.Test.Post do
       sort: [Ash.Sort.expr_sort(parent(post_followers.order), :integer)]
     )
 
+    many_to_many :tags, AshPostgres.Test.Tag do
+      public?(true)
+      through(AshPostgres.Test.PostTag)
+      sort(importance: :desc)
+    end
+
     has_many(:views, AshPostgres.Test.PostView) do
       public?(true)
     end

test/support/resources/post_tag.ex

@@ -0,0 +1,37 @@
+defmodule AshPostgres.Test.PostTag do
+  @moduledoc false
+  use Ash.Resource,
+    domain: AshPostgres.Test.Domain,
+    data_layer: AshPostgres.DataLayer
+
+  require Ash.Sort
+
+  postgres do
+    table "post_tags"
+    repo AshPostgres.TestRepo
+  end
+
+  actions do
+    default_accept(:*)
+
+    defaults([:create, :read, :update, :destroy])
+  end
+
+  identities do
+    identity(:unique_post_tag, [:post_id, :tag_id])
+  end
+
+  relationships do
+    belongs_to :post, AshPostgres.Test.Post do
+      primary_key?(true)
+      public?(true)
+      allow_nil?(false)
+    end
+
+    belongs_to :tag, AshPostgres.Test.Tag do
+      primary_key?(true)
+      public?(true)
+      allow_nil?(false)
+    end
+  end
+end

test/support/resources/tag.ex

@@ -0,0 +1,47 @@
+defmodule AshPostgres.Test.Tag do
+  @moduledoc false
+  use Ash.Resource,
+    domain: AshPostgres.Test.Domain,
+    data_layer: AshPostgres.DataLayer
+
+  require Ash.Sort
+
+  postgres do
+    table "tags"
+    repo AshPostgres.TestRepo
+  end
+
+  actions do
+    defaults([:read])
+
+    create :create do
+      accept(:*)
+    end
+  end
+
+  attributes do
+    uuid_primary_key(:id)
+    attribute(:importance, :integer, allow_nil?: false, default: 0, public?: true)
+  end
+
+  relationships do
+    many_to_many :posts, AshPostgres.Test.Post do
+      through(AshPostgres.Test.PostTag)
+      public?(true)
+    end
+
+    has_one :latest_post, AshPostgres.Test.Post do
+      public?(true)
+      no_attributes?(true)
+      filter(expr(tags.id == parent(id)))
+      sort(created_at: :desc)
+    end
+
+    has_one :post_with_highest_score, AshPostgres.Test.Post do
+      public?(true)
+      no_attributes?(true)
+      filter(expr(tags.id == parent(id)))
+      sort(score_after_winning: :desc)
+    end
+  end
+end