small rename and new test for layout

test/parfait/test_layout.rb

@@ -0,0 +1,36 @@
+require_relative "../helper"
+
+class TestLayout < MiniTest::Test
+
+  def setup
+    @mess = Virtual.machine.boot.space.first_message
+  end
+
+  def test_message_layout
+    layout = @mess.get_layout
+    assert layout
+    assert @mess.instance_variable_defined :next_message
+    assert_equal @mess.next_message , @mess.get_instance_variable(:next_message)
+  end
+
+  def test_message_by_index
+    assert_equal @mess.next_message , @mess.get_instance_variable(:next_message)
+    index = @mess.get_layout.variable_index :next_message
+    assert_equal 2 , index
+    assert_equal @mess.next_message , @mess.internal_object_get(index)
+  end
+
+  def test_layout_index
+    assert_equal @mess.get_layout , @mess.internal_object_get(1) , "mess"
+  end
+
+  def test_no_index_below_2
+    layout = @mess.get_layout
+    names = layout.object_instance_names
+    assert_equal 7 , names.get_length
+    names.each do |n|
+      assert layout.variable_index(n) > 1
+    end
+  end
+
+end