Work around enumerable string deprecation warnings

1 files changed, 9 insertions, 6 deletions

diff --git a/activesupport/lib/active_support/testing/assertions.rb b/activesupport/lib/active_support/testing/assertions.rb
index ce2f44efd6..7b19e3f35f 100644
--- a/activesupport/lib/active_support/testing/assertions.rb
+++ b/activesupport/lib/active_support/testing/assertions.rb
@@ -32,12 +32,15 @@ module ActiveSupport
       #     post :delete, :id => ...
       #   end
       def assert_difference(expressions, difference = 1, message = nil, &block)
-        expression_evaluations = Array(expressions).collect{ |expression| lambda { eval(expression, block.send(:binding)) } }
-
-        original_values = expression_evaluations.inject([]) { |memo, expression| memo << expression.call }
-        yield
-        expression_evaluations.each_with_index do |expression, i|
-          assert_equal original_values[i] + difference, expression.call, message
+        case expressions
+        when String
+          before = eval(expressions, block.send(:binding))
+          yield
+          assert_equal(before + difference, eval(expressions, block.send(:binding)), message)
+        when Enumerable
+          expressions.each { |e| assert_difference(e, difference, message, &block) }
+        else
+          raise ArgumentError, "Unrecognized expression: #{expressions.inspect}"
         end
       end