Add tests for insertion sort

sorting/insertion_sort.rb

@@ -10,8 +10,10 @@ def insertion_sort(array)
   end
   array
 end
-puts 'Enter a list of numbers separated by space'
 
-list = gets
-insertion_sort(list)
-print list
+if $0 == __FILE__
+  puts 'Enter a list of numbers separated by space'
+
+  list = gets.split.map(&:to_i)
+  p insertion_sort(list)
+end

sorting/insertion_sort_test.rb

@@ -0,0 +1,11 @@
+require 'minitest/autorun'
+require_relative './sort_tests'
+require_relative './insertion_sort'
+
+class TestInsertionSort < Minitest::Test
+  include SortTests
+
+  def sort(input)
+    insertion_sort(input)
+  end
+end