improvement: TypedStruct required field pattern matching (#2265)

- Adds generated function head for `new!/1` for required fields

closes #2253

Author: chazwatkins

lib/ash/typed_struct.ex

@@ -149,6 +149,12 @@ defmodule Ash.TypedStruct do
             end
           end)
 
+        map_required_fields_match =
+          enforce_keys
+          |> Enum.reject(&(&1 in Map.keys(defaults)))
+          |> Enum.map(&{&1, {:_, [], Elixir}})
+          |> then(&{:%{}, [], &1})
+
         map_constraints =
           [
             fields:
@@ -181,11 +187,15 @@ defmodule Ash.TypedStruct do
                constraints: unquote(Macro.escape(map_constraints))
 
              @doc "Create a new #{__MODULE__}, raising any error"
+             def new!(unquote(map_required_fields_match) = fields) do
+               fields
+               |> new()
+               |> Ash.Helpers.unwrap_or_raise!()
+             end
+
              def new!(fields) do
-               case new(fields) do
-                 {:ok, value} -> value
-                 {:error, error} -> raise Ash.Error.to_error_class(error)
-               end
+               {:error, error} = new(fields)
+               raise Ash.Error.to_error_class(error)
              end
 
              @doc "Create a new #{__MODULE__}, or return an error"

test/typed_struct_test.exs

@@ -101,6 +101,31 @@ defmodule Ash.TypedStructTest do
       assert struct.active == false
     end
 
+    test "new! returns struct when all required fields are present" do
+      assert %Ash.TypedStructTest.UserStruct{
+               id: "123e4567-e89b-12d3-a456-426614174000",
+               name: "John Doe",
+               email: "john@example.com",
+               age: 30
+             } =
+               UserStruct.new!(%{
+                 id: "123e4567-e89b-12d3-a456-426614174000",
+                 name: "John Doe",
+                 email: "john@example.com",
+                 age: 30
+               })
+    end
+
+    test "new! raises when required fields with no default are missing" do
+      assert_raise Ash.Error.Invalid, fn ->
+        UserStruct.new!(%{
+          id: "123e4567-e89b-12d3-a456-426614174000",
+          email: "invalid-email",
+          age: 30
+        })
+      end
+    end
+
     test "new! raises on errors" do
       assert_raise Ash.Error.Invalid, fn ->
         UserStruct.new!(%{