added levenshtein edit distance calculator

[biopieces.git] / code_ruby / test / maasha / test_levenshtein.rb

diff --git a/code_ruby/test/maasha/test_levenshtein.rb b/code_ruby/test/maasha/test_levenshtein.rb
new file mode 100755 (executable)
index 0000000..fca9029
--- /dev/null
+++ b/code_ruby/test/maasha/test_levenshtein.rb
@@ -0,0 +1,53 @@
+#!/usr/bin/env ruby
+$:.unshift File.join(File.dirname(__FILE__), '..', '..')
+
+# Copyright (C) 2013 Martin A. Hansen.
+
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+
+# http://www.gnu.org/copyleft/gpl.html
+
+# >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
+
+# This software is part of the Biopieces framework (www.biopieces.org).
+
+# >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
+
+require 'test/unit'
+require 'test/helper'
+require 'maasha/levenshtein'
+
+class LevenshteinTest < Test::Unit::TestCase
+  test "Levenshtein.distance returns 0 with identical strings" do
+    assert_equal(0, Levenshtein.distance("foo", "foo"))
+  end
+  
+  test "Levenshtein.distance returns s length if t is empty" do
+    assert_equal(3, Levenshtein.distance("foo", ""))
+  end
+
+  test "Levenshtein.distance returns t length if s is empty" do
+    assert_equal(5, Levenshtein.distance("", "fobar"))
+  end
+
+  test "Levenshtein.distance with mismatch only returns correctly" do
+    assert_equal(1, Levenshtein.distance("foo", "fox"))
+  end
+
+  test "Levenshtein.distance returns correctly" do
+    assert_equal(3, Levenshtein.distance("kitten", "sitting"))
+    assert_equal(3, Levenshtein.distance("Saturday", "Sunday"))
+  end
+end