Merged updates from trunk into stable branch

[feedcatcher.git] / vendor / rails / activesupport / lib / active_support / testing / assertions.rb

diff --git a/vendor/rails/activesupport/lib/active_support/testing/assertions.rb b/vendor/rails/activesupport/lib/active_support/testing/assertions.rb
new file mode 100644 (file)
index 0000000..ca51adb
--- /dev/null
+++ b/vendor/rails/activesupport/lib/active_support/testing/assertions.rb
@@ -0,0 +1,65 @@
+module ActiveSupport
+  module Testing
+    module Assertions
+      # Test numeric difference between the return value of an expression as a result of what is evaluated
+      # in the yielded block.
+      #
+      #   assert_difference 'Article.count' do
+      #     post :create, :article => {...}
+      #   end
+      #
+      # An arbitrary expression is passed in and evaluated.
+      #
+      #   assert_difference 'assigns(:article).comments(:reload).size' do
+      #     post :create, :comment => {...}
+      #   end
+      #
+      # An arbitrary positive or negative difference can be specified. The default is +1.
+      #
+      #   assert_difference 'Article.count', -1 do
+      #     post :delete, :id => ...
+      #   end
+      #
+      # An array of expressions can also be passed in and evaluated.
+      #
+      #   assert_difference [ 'Article.count', 'Post.count' ], +2 do
+      #     post :create, :article => {...}
+      #   end
+      #
+      # A error message can be specified.
+      #
+      #   assert_difference 'Article.count', -1, "An Article should be destroyed" do
+      #     post :delete, :id => ...
+      #   end
+      def assert_difference(expression, difference = 1, message = nil, &block)
+        b = block.send(:binding)
+        exps = Array.wrap(expression)
+        before = exps.map { |e| eval(e, b) }
+
+        yield
+
+        exps.each_with_index do |e, i|
+          error = "#{e.inspect} didn't change by #{difference}"
+          error = "#{message}.\n#{error}" if message
+          assert_equal(before[i] + difference, eval(e, b), error)
+        end
+      end
+
+      # Assertion that the numeric result of evaluating an expression is not changed before and after
+      # invoking the passed in block.
+      #
+      #   assert_no_difference 'Article.count' do
+      #     post :create, :article => invalid_attributes
+      #   end
+      #
+      # A error message can be specified.
+      #
+      #   assert_no_difference 'Article.count', "An Article should not be destroyed" do
+      #     post :create, :article => invalid_attributes
+      #   end
+      def assert_no_difference(expression, message = nil, &block)
+        assert_difference expression, 0, message, &block
+      end
+    end
+  end
+end