refactor: move immutable error expr from AshSql into AshPostgres (#633)

Author: stevebrambilla

lib/extensions/immutable_raise_error.ex

@@ -28,6 +28,8 @@ defmodule AshPostgres.Extensions.ImmutableRaiseError do
 
   use AshPostgres.CustomExtension, name: "immutable_raise_error", latest_version: 1
 
+  require Ecto.Query
+
   @impl true
   def install(0) do
     ash_raise_error_immutable()
@@ -71,4 +73,157 @@ defmodule AshPostgres.Extensions.ImmutableRaiseError do
     \"\"\")
     """
   end
+
+  @doc false
+  def immutable_error_expr(
+        query,
+        %Ash.Query.Function.Error{arguments: [exception, input]} = value,
+        bindings,
+        embedded?,
+        acc,
+        type
+      ) do
+    acc = %{acc | has_error?: true}
+
+    {encoded, acc} =
+      if Ash.Expr.expr?(input) do
+        frag_parts =
+          Enum.flat_map(input, fn {key, value} ->
+            if Ash.Expr.expr?(value) do
+              [
+                expr: to_string(key),
+                raw: "::text, ",
+                expr: value,
+                raw: ", "
+              ]
+            else
+              [
+                expr: to_string(key),
+                raw: "::text, ",
+                expr: value,
+                raw: "::jsonb, "
+              ]
+            end
+          end)
+
+        frag_parts =
+          List.update_at(frag_parts, -1, fn {:raw, text} ->
+            {:raw, String.trim_trailing(text, ", ") <> "))"}
+          end)
+
+        AshSql.Expr.dynamic_expr(
+          query,
+          %Ash.Query.Function.Fragment{
+            embedded?: false,
+            arguments:
+              [
+                raw: "jsonb_build_object('exception', ",
+                expr: inspect(exception),
+                raw: "::text, 'input', jsonb_build_object("
+              ] ++
+                frag_parts
+          },
+          bindings,
+          embedded?,
+          nil,
+          acc
+        )
+      else
+        {Jason.encode!(%{exception: inspect(exception), input: Map.new(input)}), acc}
+      end
+
+    dynamic_type =
+      if type do
+        # This is a type hint, if we're raising an error, we tell it what the value
+        # type *would* be in this expression so that we can return a "NULL" of that type
+        # its weird, but there isn't any other way that I can tell :)
+        AshSql.Expr.validate_type!(query, type, value)
+
+        type =
+          AshSql.Expr.parameterized_type(
+            bindings.sql_behaviour,
+            type,
+            [],
+            :expr
+          )
+
+        Ecto.Query.dynamic(type(fragment("NULL"), ^type))
+      else
+        nil
+      end
+
+    case {dynamic_type, immutable_error_expr_token(query, bindings)} do
+      {_, nil} ->
+        :error
+
+      {nil, row_token} ->
+        {:ok,
+         Ecto.Query.dynamic(
+           fragment("ash_raise_error_immutable(?::jsonb, ?)", ^encoded, ^row_token)
+         ), acc}
+
+      {dynamic_type, row_token} ->
+        {:ok,
+         Ecto.Query.dynamic(
+           fragment(
+             "ash_raise_error_immutable(?::jsonb, ?, ?)",
+             ^encoded,
+             ^dynamic_type,
+             ^row_token
+           )
+         ), acc}
+    end
+  end
+
+  # Returns a row-dependent token to prevent constant-folding for immutable functions.
+  defp immutable_error_expr_token(query, bindings) do
+    resource = query.__ash_bindings__.resource
+    ref_binding = bindings.root_binding
+
+    pk_attr_names = Ash.Resource.Info.primary_key(resource)
+
+    attr_names =
+      case pk_attr_names do
+        [] ->
+          case Ash.Resource.Info.attributes(resource) do
+            [%{name: name} | _] -> [name]
+            _ -> []
+          end
+
+        pk ->
+          pk
+      end
+
+    if ref_binding && attr_names != [] do
+      value_exprs =
+        Enum.map(attr_names, fn attr_name ->
+          if bindings[:parent?] &&
+               ref_binding not in List.wrap(bindings[:lateral_join_bindings]) do
+            Ecto.Query.dynamic(field(parent_as(^ref_binding), ^attr_name))
+          else
+            Ecto.Query.dynamic(field(as(^ref_binding), ^attr_name))
+          end
+        end)
+
+      row_parts =
+        value_exprs
+        |> Enum.map(&{:casted_expr, &1})
+        |> Enum.intersperse({:raw, ", "})
+
+      {%Ecto.Query.DynamicExpr{} = token, _acc} =
+        AshSql.Expr.dynamic_expr(
+          query,
+          %Ash.Query.Function.Fragment{
+            embedded?: false,
+            arguments: [raw: "ROW("] ++ row_parts ++ [raw: ")"]
+          },
+          AshSql.Expr.set_location(bindings, :sub_expr),
+          false
+        )
+
+      token
+    else
+      nil
+    end
+  end
 end

lib/sql_implementation.ex

@@ -200,6 +200,31 @@ defmodule AshPostgres.SqlImplementation do
     end
   end
 
+  def expr(
+        query,
+        %Ash.Query.Function.Error{} = value,
+        bindings,
+        embedded?,
+        acc,
+        type
+      ) do
+    resource = query.__ash_bindings__.resource
+    repo = AshSql.dynamic_repo(resource, AshPostgres.SqlImplementation, query)
+
+    if repo.immutable_expr_error?() do
+      AshPostgres.Extensions.ImmutableRaiseError.immutable_error_expr(
+        query,
+        value,
+        bindings,
+        embedded?,
+        acc,
+        type
+      )
+    else
+      :error
+    end
+  end
+
   def expr(
         _query,
         _expr,
@@ -334,9 +359,4 @@ defmodule AshPostgres.SqlImplementation do
 
     {types, new_returns || returns}
   end
-
-  @impl true
-  def immutable_errors?(repo) do
-    repo.immutable_expr_error?()
-  end
 end

mix.exs

@@ -168,7 +168,6 @@ defmodule AshPostgres.MixProject do
     [
       {:ash, ash_version("~> 3.5 and >= 3.5.35")},
       {:spark, "~> 2.3 and >= 2.3.4"},
-      # TODO: bump to next ash_sql release
       {:ash_sql, ash_sql_version(git: "https://github.com/ash-project/ash_sql.git")},
       {:igniter, "~> 0.6 and >= 0.6.14", optional: true},
       {:ecto_sql, "~> 3.13"},

mix.lock

@@ -1,6 +1,6 @@
 %{
   "ash": {:hex, :ash, "3.5.43", "222f9a8ac26ad3b029f8e69306cc83091c992d858b4538af12e33a148f301cab", [:mix], [{:decimal, "~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:ecto, "~> 3.7", [hex: :ecto, repo: "hexpm", optional: false]}, {:ets, "~> 0.8", [hex: :ets, repo: "hexpm", optional: false]}, {:igniter, ">= 0.6.29 and < 1.0.0-0", [hex: :igniter, repo: "hexpm", optional: true]}, {:jason, ">= 1.0.0", [hex: :jason, repo: "hexpm", optional: false]}, {:picosat_elixir, "~> 0.2", [hex: :picosat_elixir, repo: "hexpm", optional: true]}, {:plug, ">= 0.0.0", [hex: :plug, repo: "hexpm", optional: true]}, {:reactor, "~> 0.11", [hex: :reactor, repo: "hexpm", optional: false]}, {:simple_sat, ">= 0.1.1 and < 1.0.0-0", [hex: :simple_sat, repo: "hexpm", optional: true]}, {:spark, ">= 2.3.3 and < 3.0.0-0", [hex: :spark, repo: "hexpm", optional: false]}, {:splode, ">= 0.2.6 and < 1.0.0-0", [hex: :splode, repo: "hexpm", optional: false]}, {:stream_data, "~> 1.0", [hex: :stream_data, repo: "hexpm", optional: false]}, {:telemetry, "~> 1.1", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "48b2aa274c524f5b968c563dd56aec8f9b278c529c8aa46e6fe0ca564c26cc1c"},
-  "ash_sql": {:git, "https://github.com/ash-project/ash_sql.git", "65854408e7ce129f78fabafb0a4393f0142da6a6", []},
+  "ash_sql": {:git, "https://github.com/ash-project/ash_sql.git", "3044c0555dbe6733d16868951ee89e6d5ef336fa", []},
   "benchee": {:hex, :benchee, "1.4.0", "9f1f96a30ac80bab94faad644b39a9031d5632e517416a8ab0a6b0ac4df124ce", [:mix], [{:deep_merge, "~> 1.0", [hex: :deep_merge, repo: "hexpm", optional: false]}, {:statistex, "~> 1.0", [hex: :statistex, repo: "hexpm", optional: false]}, {:table, "~> 0.1.0", [hex: :table, repo: "hexpm", optional: true]}], "hexpm", "299cd10dd8ce51c9ea3ddb74bb150f93d25e968f93e4c1fa31698a8e4fa5d715"},
   "bunt": {:hex, :bunt, "1.0.0", "081c2c665f086849e6d57900292b3a161727ab40431219529f13c4ddcf3e7a44", [:mix], [], "hexpm", "dc5f86aa08a5f6fa6b8096f0735c4e76d54ae5c9fa2c143e5a1fc7c1cd9bb6b5"},
   "credo": {:hex, :credo, "1.7.12", "9e3c20463de4b5f3f23721527fcaf16722ec815e70ff6c60b86412c695d426c1", [:mix], [{:bunt, "~> 0.2.1 or ~> 1.0", [hex: :bunt, repo: "hexpm", optional: false]}, {:file_system, "~> 0.2 or ~> 1.0", [hex: :file_system, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "8493d45c656c5427d9c729235b99d498bd133421f3e0a683e5c1b561471291e5"},