Unit name normalization

Gemfile.lock

@@ -200,6 +200,3 @@ DEPENDENCIES
   uglifier (>= 1.3.0)
   unitwise (~> 2.0.0)
   web-console (~> 2.0)
-
-BUNDLED WITH
-   1.10.6

app/models/unit_conversion.rb

@@ -2,6 +2,22 @@ module UnitConversion
 
   UNIT_PARSING_REGEX = /^(?<value>(?:-?[0-9]+)?(?:\.?[0-9]*)?)\s*(?<unit>[a-z\/.\-()0-9]+)$/
 
+  UNIT_ALIASES = {
+      cup: %w(cups c),
+      tablespoon: %w(tbsp tbs tablespoons),
+      teaspoon: %w(tsp teaspoons),
+      ounce: %w(oz ounces),
+      pound: %w(pounds lb lbs),
+      pint: %w(pints),
+      quart: %w(quarts),
+      gallon: %w(gallons ga),
+
+      gram: %w(grams g),
+      kilogram: %w(kilograms kg)
+  }
+
+  UNIT_ALIAS_MAP = Hash[UNIT_ALIASES.map { |unit, values| values.map { |v| [v, unit] } }.flatten(1)]
+
   class UnparseableUnitError < StandardError
   end
 
@@ -28,5 +44,15 @@ module UnitConversion
       unit.compatible_with? Unitwise(1, 'g/ml')
     end
 
+    def normalize_unit_names(unit_description)
+      result = unit_description.dup
+
+      result = result.downcase.gsub(/[a-z]+/) do |match|
+        UNIT_ALIAS_MAP[match] || match
+      end
+
+      result
+    end
+
   end
 end