fix(formatter): fix small issue where there was only one newline added

lib/elixir/lib/code/formatter.ex

@@ -637,8 +637,8 @@ defmodule Code.Formatter do
   end
 
   defp block_args_to_algebra(args, min_line, max_line, state) do
-    quoted_to_algebra = fn {kind, meta, _} = arg, _args, state ->
-      newlines = meta[:end_of_expression][:newlines] || 1
+    quoted_to_algebra = fn {kind, meta, _} = arg, args, state ->
+      newlines = maybe_add_newlines({kind, args}, meta)
       {doc, state} = quoted_to_algebra(arg, :block, state)
       {{doc, block_next_line(kind), newlines}, state}
     end
@@ -656,6 +656,14 @@ defmodule Code.Formatter do
   defp block_next_line(:@), do: @empty
   defp block_next_line(_), do: break("")
 
+  defp maybe_add_newlines({:def, [{:@, _, _} = _next | _]}, _meta) do
+    @newlines
+  end
+
+  defp maybe_add_newlines(_, meta) do
+    meta[:end_of_expression][:newlines] || 1
+  end
+
   ## Operators
 
   defp maybe_unary_op_to_algebra(fun, meta, args, context, state) do

lib/elixir/test/elixir/code_formatter/general_test.exs

@@ -869,6 +869,56 @@ defmodule Code.Formatter.GeneralTest do
       assert_format bad, good
     end
 
+    test "with def followed by module attribute" do
+      bad = """
+      defmodule Example do
+        @impl FooA
+        def a(), do: :something
+        @impl FooB
+        def b() do
+          :something_else
+        end
+      end
+      """
+
+      good = """
+      defmodule Example do
+        @impl FooA
+        def a(), do: :something
+
+        @impl FooB
+        def b() do
+          :something_else
+        end
+      end
+      """
+
+      assert_format bad, good
+    end
+
+    test "with def followed by def" do
+      bad = """
+      defmodule Example do
+        def a(), do: :something
+        def b() do
+          :something_else
+        end
+      end
+      """
+
+      good = """
+      defmodule Example do
+        def a(), do: :something
+
+        def b() do
+          :something_else
+        end
+      end
+      """
+
+      assert_format bad, good
+    end
+
     test "with multiple defs" do
       assert_same """
       def foo(:one), do: 1