Mi Kata de enero usando ruby

agutierrez/string_calculator.rb

@@ -0,0 +1,35 @@
+class StringCalculator
+
+  DEFAULT_DELIMITER = ","
+
+  def add(raw_string)
+    return 0 if raw_string.empty?
+    cleaned_string = clean_string(raw_string)
+    addends = extract_addends(cleaned_string)
+    addends.reduce(:+)
+  end # add
+
+  def clean_string(dirty_string)
+    new_string = dirty_string
+    if dirty_string[0] == "\\" then
+      delimiters = extract_delimiters(dirty_string[1..dirty_string.index("\n")-1])
+      new_string = dirty_string[dirty_string.index("\n")+1..dirty_string.length-1]
+      delimiters.each { |de| new_string.gsub!(de,DEFAULT_DELIMITER) }
+    end
+    new_string = new_string.gsub("\n", DEFAULT_DELIMITER)
+  end
+
+  def extract_delimiters(delimiter_string)
+    return delimiter_string.gsub("][", " ").gsub(/[\[,\]]/, "").split
+  end
+
+  def extract_addends(addends_string)
+    working_array = addends_string.split(DEFAULT_DELIMITER).collect { |a| a.to_i }
+    negatives = []
+    working_array.each { |wa| negatives << wa if wa < 0 }
+    working_array.delete_if { |wa| wa > 999 }
+    raise "No negatives allowed: #{negatives.join(', ')}" if !negatives.empty?
+    return working_array
+  end
+
+end # class

agutierrez/string_calculator_test.rb

@@ -0,0 +1,31 @@
+require './string_calculator'
+
+describe 'StringCalculator', '#add' do
+
+  before(:each) do
+    @kata = StringCalculator.new
+  end
+
+  Kata_Data = [
+    ["Should return 0 with an empty string", "", 0],
+    ["Should return an integer with a text number", "2", 2],
+    ["Should return the sum of two numbers separated by a comma", "2,3", 5],
+    ["Should accept \n as a valid separator", "2\n3,5", 10],
+    ["Should accept custom char separator between \\ and \n", "\\**\n2,3**4", 9],
+    ["Should ignore numbers greater than 1000", "2,1002,6", 8],
+    ["Should allow multiple delimiters between []", "\\[**][;]\n2**;5;6", 13]
+  ]
+
+  Kata_Data.each do |kataItem|
+
+    it kataItem[0] do
+      @kata.add(kataItem[1]).should == kataItem[2]
+    end
+
+  end
+
+  it "Should raise an error if there is a negative" do
+    lambda{@kata.add("1,-2,4,-5")}.should raise_error "No negatives allowed: -2, -5"
+  end
+
+end