including brazilian cpf

lib/id_number_latam/br_cpf.rb

@@ -0,0 +1,40 @@
+module IdNumberLatam
+  class BrCPF < Base
+    # This Class allows validating the Argentinean Number (DNI). 
+    # This document does not have a verification digit.
+
+    def initialize(id_number, opts = {})
+      super
+      @country = :br
+      @digit   = unformat[-2..-1]
+    end
+
+    def unformat
+      id_number.gsub(/\D/, "")
+    end
+
+    def format
+      cpf = unformat
+      groups = cpf.match(/(\d{3})(\d{3})(\d{3})(\d{2})/)[1..-1]
+      formatted_cpf="%s.%s.%s-%s" % groups
+    end
+
+    def valid?
+      return false unless valid_length
+      cpf = unformat
+      digits = (cpf[-2..-1]).to_i
+      first_slice, second_slice = cpf[0..-3], cpf[0..-2]
+      pre_calc_lambda = lambda { |x, str| str.chars.each_with_index.reduce(0) { |acc, (d, i)| (acc += d.to_i*(x-i)) } }
+      first_digit = pre_calc_lambda.call(10, first_slice) * 10 % 11 
+      first_digit = first_digit == 10 ? 0 : first_digit
+      second_digit = pre_calc_lambda.call(11, second_slice) * 10 % 11
+      verification_digits = ("%s%s" % [first_digit, second_digit]).to_i
+      return true unless verification_digits != digits
+    end
+
+    def valid_length
+      unformat.size == 11
+    end
+
+  end
+end

spec/id_number_latam/br_cpf_spec.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+RSpec.describe IdNumberLatam::BrCPF do
+  subject { described_class.new("529.982.247-25") }
+
+  context "with a valid id number" do
+    it "valid id_number" do
+      expect(subject.valid?).to be_truthy
+    end
+
+    it "unformat id_number" do
+      expect(subject.unformat).to eq("52998224725")
+    end
+
+    it "format id_number" do
+      expect(subject.format).to eq("529.982.247-25")
+    end
+  end
+end