Add Money.with_rounding_mode as a replacement for Money.roudning_mode…

… with a block (tonsky#850)

lib/money/money.rb

@@ -186,32 +186,36 @@ def self.inherited(base)
 
   setup_defaults
 
-  # Use this to return the rounding mode.  You may also pass a
-  # rounding mode and a block to temporarily change it.  It will
-  # then return the results of the block instead.
+  # Use this to return the rounding mode.
   #
   # @param [BigDecimal::ROUND_MODE] mode
   #
-  # @return [BigDecimal::ROUND_MODE,Yield] rounding mode or block results
+  # @return [BigDecimal::ROUND_MODE] rounding mode
+  def self.rounding_mode(mode = nil)
+    return Thread.current[:money_rounding_mode] || @rounding_mode unless mode
+
+    warn "[DEPRECATION] calling `rounding_mode` with a block is deprecated. Please use `.with_rounding_mode` instead."
+    with_rounding_mode(mode) { yield }
+  end
+
+  # This method temporarily changes the rounding mode. It will then return the
+  # results of the block instead.
+  #
+  # @param [BigDecimal::ROUND_MODE] mode
+  #
+  # @return [BigDecimal::ROUND_MODE,Yield] block results
   #
   # @example
-  #   fee = Money.rounding_mode(BigDecimal::ROUND_HALF_UP) do
+  #   fee = Money.with_rounding_mode(BigDecimal::ROUND_HALF_UP) do
   #     Money.new(1200) * BigDecimal('0.029')
   #   end
-  def self.rounding_mode(mode = nil)
-    if mode.nil?
-      Thread.current[:money_rounding_mode] || @rounding_mode
-    else
-      begin
-        Thread.current[:money_rounding_mode] = mode
-        yield
-      ensure
-        Thread.current[:money_rounding_mode] = nil
-      end
-    end
+  def self.with_rounding_mode(mode)
+    Thread.current[:money_rounding_mode] = mode
+    yield
+  ensure
+    Thread.current[:money_rounding_mode] = nil
   end
 
-
   # Adds a new exchange rate to the default bank and return the rate.
   #
   # @param [Currency, String, Symbol] from_currency Currency to exchange from.

spec/money_spec.rb

@@ -193,13 +193,21 @@
       expect(Money.from_amount(1, "USD", bank).bank).to eq bank
     end
 
-    it 'rounds using rounding_mode' do
+    it 'warns about rounding_mode deprecation' do
+      expect(Money).to receive(:warn)
       expect(Money.from_amount(1.999).to_d).to eq 2
       expect(Money.rounding_mode(BigDecimal::ROUND_DOWN) do
         Money.from_amount(1.999).to_d
       end).to eq 1.99
     end
 
+    it 'rounds using with_rounding_mode' do
+      expect(Money.from_amount(1.999).to_d).to eq 2
+      expect(Money.with_rounding_mode(BigDecimal::ROUND_DOWN) do
+        Money.from_amount(1.999).to_d
+      end).to eq 1.99
+    end
+
     context 'given a currency is provided' do
       context 'and the currency is nil' do
         let(:currency) { nil }