adding gem file executable

templates/impl.rb

@@ -0,0 +1,17 @@
+#prepare the input which is a string containing new lines
+def parse(input)
+  data = []
+  input.each_line do |line|
+    data << line
+  end
+  data
+end
+
+# result should a single string or integer
+def calculate(data)
+  result = ""
+  data.each do |d|
+    result = d
+  end
+  result
+end

templates/run.rb

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+require_relative "impl"
+
+def print(result)
+  if result.is_a? Array
+    result.map! {|l| "#{l}\n" } 
+  end
+  
+  puts result
+end
+
+def run
+  puts "running your implementation"
+  input = File.new("%day_name%/data").read
+  data = parse(input)
+  result = calculate(data)
+  print(result)
+end
+
+run

templates/test.rb

@@ -0,0 +1,22 @@
+require_relative "impl"
+
+INPUT = <<~IN
+%example_input%
+IN
+
+RESULT = %example_result%
+
+def test_example
+  parsed = parse(INPUT)
+  result = calculate(parsed)
+
+  if result == RESULT
+    puts "Test successful. Now run with real input"
+    puts "ruby %day_name%/run.rb"
+  else
+    puts "Test failed"
+    puts "expected \"#{RESULT}\" got \"#{result}\""
+  end
+end
+
+test_example