Rename/-work find_by_iso_numeric and add specs.

lib/money/currency.rb

@@ -38,16 +38,17 @@ def find(id)
       # Lookup a currency with given +num+ as an ISO 4217 numeric and returns an
       # +Currency+ instance on success, +nil+ otherwise.
       #
-      # @param [Integer, #to_i] num used to look into +table+ in +iso_numeric+
-      # and find the right currency id.
+      # @param [#to_s] num used to look into +table+ in +iso_numeric+ and find
+      # the right currency id.
       #
       # @return [Money::Currency]
       #
       # @example
-      #   Money::Currency.find_numeric(978) #=> #<Money::Currency id: eur ...>
-      #   Money::Currency.find_numeric(1) #=> nil
-      def find_numeric(num)
-        id = (self.table.select { |cur| self.table[cur][:iso_numeric].to_i == num }).keys.first
+      #   Money::Currency.find_by_iso_numeric(978) #=> #<Money::Currency id: eur ...>
+      #   Money::Currency.find_by_iso_numeric('001') #=> nil
+      def find_by_iso_numeric(num)
+        num = num.to_s
+        id, garbage = self.table.find{|key, currency| currency[:iso_numeric] == num}
         new(id) if self.table[id]
       end
 

spec/currency_spec.rb

@@ -22,6 +22,27 @@
     end
   end
 
+  describe ".find_by_iso_numeric" do
+    it "returns currency matching given numeric code" do
+      Money::Currency.find_by_iso_numeric(978).should          == Money::Currency.new(:eur)
+      Money::Currency.find_by_iso_numeric(208).should_not      == Money::Currency.new(:eur)
+      Money::Currency.find_by_iso_numeric('840').should        == Money::Currency.new(:usd)
+
+      class Mock
+        def to_s
+          '208'
+        end
+      end
+      Money::Currency.find_by_iso_numeric(Mock.new).should     == Money::Currency.new(:dkk)
+      Money::Currency.find_by_iso_numeric(Mock.new).should_not == Money::Currency.new(:usd)
+    end
+
+    it "returns nil if no currency has the given numeric code" do
+      Money::Currency.find_by_iso_numeric('non iso 4217 numeric code').should == nil
+      Money::Currency.find_by_iso_numeric(0).should                           == nil
+    end
+  end
+
   describe ".wrap" do
     it "returns nil if object is nil" do
       Money::Currency.wrap(nil).should == nil