add class to wrap sensitive values

test/test_sensitive.rb

@@ -0,0 +1,26 @@
+require "minitest/autorun"
+
+$LOAD_PATH.unshift File.dirname(__FILE__) + "/../lib"
+
+require "sensitive"
+
+ALPHABET = ("a".."z").reduce(:concat)
+
+class TestSensitive < Minitest::Test
+  def setup
+    @s = Sensitive.new ALPHABET
+  end
+
+  def test_initialize
+    assert_equal @s.to_s, "ab" + "*" * 22 + "yz"
+  end
+
+  def test_unwrap
+    assert_equal @s.unwrap, ALPHABET
+  end
+
+  def test_using_a_different_mask_character
+    s = Sensitive.new ALPHABET, ch: "x"
+    assert_equal s.to_s, "ab" + "x" * 22 + "yz"
+  end
+end