add the simplest possible hash replacement with tests

test/unit/list.rb

@@ -0,0 +1,42 @@
+require_relative "../helper"
+
+class TestLists < MiniTest::Test
+
+  def setup
+    @list = List.new
+  end
+  def test_list_create
+    assert @list.empty?
+  end
+  def test_empty_list_doesnt_return
+    assert_equal nil , @list.get(3)
+    assert_equal nil , @list.get(:any)
+  end
+  def test_one_set1
+    assert_equal 1 , @list.set(1,1)
+  end
+  def test_one_set2
+    assert_equal :some , @list.set(1,:some)
+  end
+  def test_two_sets
+    assert_equal 1 , @list.set(1,1)
+    assert_equal :some , @list.set(1,:some)
+  end
+  def test_one_get1
+    test_one_set1
+    assert_equal 1 , @list.get(1)
+  end
+  def test_one_get2
+    test_one_set2
+    assert_equal :some , @list.get(1)
+  end
+  def test_many_get
+    shouldda  = { :one => 1 , :two => 2 , :three => 3}
+    shouldda.each do |k,v|
+      @list.set(k,v)
+    end
+    shouldda.each do |k,v|
+      assert_equal v , @list.get(k)
+    end
+  end
+end