1 files changed, 18 insertions, 0 deletions
diff --git a/lib/puppet/util/monkey_patches.rb b/lib/puppet/util/monkey_patches.rb
index 6b5af8350..85854a04c 100644
--- a/lib/puppet/util/monkey_patches.rb
+++ b/lib/puppet/util/monkey_patches.rb
@@ -48,3 +48,21 @@ if RUBY_VERSION == '1.8.7'
   end
 end
 
+class Object
+  # The following code allows callers to make assertions that are only
+  # checked when the environment variable PUPPET_ENABLE_ASSERTIONS is
+  # set to a non-empty string.  For example:
+  #
+  #   assert_that { condition }
+  #   assert_that(message) { condition }
+  if ENV["PUPPET_ENABLE_ASSERTIONS"].to_s != ''
+    def assert_that(message = nil)
+      unless yield
+        raise Exception.new("Assertion failure: #{message}")
+      end
+    end
+  else
+    def assert_that(message = nil)
+    end
+  end
+end