Re-enabled the old behavior for should_change and should_not_change m…

…acros, but displaying a deprecation warning when they are used without a block

lib/shoulda/macros.rb

@@ -36,10 +36,17 @@ def should_change(description, options = {}, &block)
       stmt << " to #{to.inspect}" if to
       stmt << " by #{by.inspect}" if by
 
-      before = lambda { @_before_should_change = block.bind(self).call }
+      if block_given?
+        code = block
+      else
+        warn "[DEPRECATION] should_change(expression, options) is deprecated. " <<
+             "Use should_change(description, options) { code } instead."
+        code = lambda { eval(description) }
+      end
+      before = lambda { @_before_should_change = code.bind(self).call }
       should stmt, :before => before do
         old_value = @_before_should_change
-        new_value = block.bind(self).call
+        new_value = code.bind(self).call
         assert_operator from, :===, old_value, "#{description} did not originally match #{from.inspect}" if from
         assert_not_equal old_value, new_value, "#{description} did not change" unless by == 0
         assert_operator to, :===, new_value, "#{description} was not changed to match #{to.inspect}" if to
@@ -60,9 +67,16 @@ def should_change(description, options = {}, &block)
     #     should_not_change("the number of posts") { Post.count }
     #   end
     def should_not_change(description, &block)
-      before = lambda { @_before_should_not_change = block.bind(self).call }
+      if block_given?
+        code = block
+      else
+        warn "[DEPRECATION] should_not_change(expression) is deprecated. " <<
+             "Use should_not_change(description) { code } instead."
+        code = lambda { eval(description) }
+      end
+      before = lambda { @_before_should_not_change = code.bind(self).call }
       should "not change #{description}", :before => before do
-        new_value = block.bind(self).call
+        new_value = code.bind(self).call
         assert_equal @_before_should_not_change, new_value, "#{description} changed"
       end
     end

test/other/helpers_test.rb

@@ -93,6 +93,13 @@ class HelpersTest < ActiveSupport::TestCase # :nodoc:
       should_change("the number of elements", :to => 4) { @a.length }
       should_change("the first element", :by => 0) { @a[0] }
       should_not_change("the first element") { @a[0] }
+
+      # tests for deprecated behavior
+      should_change "@a.length", :by => 1
+      should_change "@a.length", :from => 3
+      should_change "@a.length", :to => 4
+      should_change "@a[0]", :by => 0
+      should_not_change "@a[0]"
     end
 
     context "after replacing it with an array of strings" do
@@ -106,6 +113,14 @@ class HelpersTest < ActiveSupport::TestCase # :nodoc:
       should_change("the second element", :from => 2, :to => "b") { @a[1] }
       should_change("the third element", :from => /\d/, :to => /\w/) { @a[2] }
       should_change("the last element", :to => String) { @a[3] }
+
+      # tests for deprecated behavior
+      should_change "@a.length", :by => 3
+      should_change "@a.length", :from => 3, :to => 6, :by => 3
+      should_change "@a[0]"
+      should_change "@a[1]", :from => 2, :to => "b"
+      should_change "@a[2]", :from => /\d/, :to => /\w/
+      should_change "@a[3]", :to => String
     end
   end