Merge pull request #81 from djberg96/digest_uuid

Extend the Digest::UUID module with the clean method

lib/more_core_extensions/all.rb

@@ -3,6 +3,7 @@
 require 'more_core_extensions/core_ext/array'
 require 'more_core_extensions/core_ext/benchmark'
 require 'more_core_extensions/core_ext/class'
+require 'more_core_extensions/core_ext/digest'
 require 'more_core_extensions/core_ext/hash'
 require 'more_core_extensions/core_ext/math'
 require 'more_core_extensions/core_ext/module'

lib/more_core_extensions/core_ext/digest.rb

@@ -0,0 +1 @@
+require 'more_core_extensions/core_ext/digest/uuid'

lib/more_core_extensions/core_ext/digest/uuid.rb

@@ -0,0 +1,26 @@
+require 'active_support/core_ext/digest/uuid'
+
+module Digest
+  module UUID
+    UUID_REGEX_FORMAT = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/.freeze
+
+    # Takes a UUID string of varying formats and cleans it. It will strip invalid characters,
+    # such as leading and trailing brackets as well as whitespace. The result is a lowercased,
+    # canonical UUID string.
+    #
+    # If the +guid+ argument is nil or blank, then nil is returned. If the +guid+ is already
+    # clean, then no additional cleaning occurs, and it is returned as-is.
+    #
+    # @param guid [String] A string that should more or less represent a UUID.
+    # @return [String] A lowercase v4 UUID string stripped of any extraneous characters.
+    #
+    def self.clean(guid)
+      return nil if guid.nil?
+      g = guid.to_s.downcase
+      return nil if g.strip.empty?
+      return g if g.length == 36 && g =~ UUID_REGEX_FORMAT
+      g.delete!('^0-9a-f')
+      g.sub!(/^([0-9a-f]{8})([0-9a-f]{4})([0-9a-f]{4})([0-9a-f]{4})([0-9a-f]{12})$/, '\1-\2-\3-\4-\5')
+    end
+  end
+end

spec/core_ext/digest/uuid_spec.rb

@@ -0,0 +1,34 @@
+describe Digest::UUID do
+  context "clean" do
+    let(:expected) { '01234567-89ab-cdef-abcd-ef0123456789' }
+
+    it "handles a valid lowercase guid" do
+      expect(described_class.clean('01234567-89ab-cdef-abcd-ef0123456789')).to eq(expected)
+    end
+
+    it "handles a Microsoft-style guid" do
+      expect(described_class.clean('{01234567-89ab-cdef-abcd-ef0123456789}')).to eq(expected)
+    end
+
+    it "handles a valid uppercase guid" do
+      expect(described_class.clean('01234567-89AB-CDEF-abcd-ef0123456789')).to eq(expected)
+    end
+
+    it "handles a valid guid with an invalid structure" do
+      expect(described_class.clean('01 23 45 67 89 AB CD EF-AB CD EF 01 23 45 67 89')).to eq(expected)
+    end
+
+    it "handles an explicit nil or blank string" do
+      expect(described_class.clean(nil)).to be_nil
+      expect(described_class.clean('')).to be_nil
+    end
+
+    it "handles invalid guids" do
+      expect(described_class.clean('sdkjfLSDLK')).to be_nil
+      expect(described_class.clean('sdkjfLSD-LKJF-8367-41df-FLKD209alkfd')).to be_nil
+      expect(described_class.clean('01234567-89AB-CDEF-abcd-efgggggggggg')).to be_nil
+      expect(described_class.clean('01234567-89AB-CDEF-abcd-ef0123456789a')).to be_nil
+      expect(described_class.clean('01234567-89AB-CDEF-abcd-ef012345678')).to be_nil
+    end
+  end
+end