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Added breakpoints to stand-alone Active Record, so we can use them in…

… tests for AR

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@218 5ecf4fe2-1ee6-0310-87b1-e25e094e27de
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1 parent a2130c2 commit 01f05551c0cbec5c4be93ee6d9f1db48dfba892c @dhh dhh committed Dec 19, 2004
@@ -0,0 +1,81 @@
+begin
+ require 'simplecc'
+rescue LoadError
+ def Continuation.create(*args, &block)
+ cc = nil; result = callcc {|c| cc = c; block.call(cc) if block and args.empty?}
+ result ||= args
+ return *[cc, *result]
+ end
+end
+
+# This method returns the binding of the method that called your
+# method. It will raise an Exception when you're not inside a method.
+#
+# It's used like this:
+# def inc_counter(amount = 1)
+# Binding.of_caller do |binding|
+# # Create a lambda that will increase the variable 'counter'
+# # in the caller of this method when called.
+# inc = eval("lambda { |arg| counter += arg }", binding)
+# # We can refer to amount from inside this block safely.
+# inc.call(amount)
+# end
+# # No other statements can go here. Put them inside the block.
+# end
+# counter = 0
+# 2.times { inc_counter }
+# counter # => 2
+#
+# Binding.of_caller must be the last statement in the method.
+# This means that you will have to put everything you want to
+# do after the call to Binding.of_caller into the block of it.
+# This should be no problem however, because Ruby has closures.
+# If you don't do this an Exception will be raised. Because of
+# the way that Binding.of_caller is implemented it has to be
+# done this way.
+def Binding.of_caller(&block)
+ old_critical = Thread.critical
+ Thread.critical = true
+ count = 0
+ cc, result, error, extra_data = Continuation.create(nil, nil)
+ error.call if error
+
+ tracer = lambda do |*args|
+ type, context, extra_data = args[0], args[4], args
+ if type == "return"
+ count += 1
+ # First this method and then calling one will return --
+ # the trace event of the second event gets the context
+ # of the method which called the method that called this
+ # method.
+ if count == 2
+ # It would be nice if we could restore the trace_func
+ # that was set before we swapped in our own one, but
+ # this is impossible without overloading set_trace_func
+ # in current Ruby.
+ set_trace_func(nil)
+ cc.call(eval("binding", context), nil, extra_data)
+ end
+ elsif type == "line" then
+ nil
+ elsif type == "c-return" and extra_data[3] == :set_trace_func then
+ nil
+ else
+ set_trace_func(nil)
+ error_msg = "Binding.of_caller used in non-method context or " +
+ "trailing statements of method using it aren't in the block."
+ cc.call(nil, lambda { raise(ArgumentError, error_msg) }, nil)
+ end
+ end
+
+ unless result
+ set_trace_func(tracer)
+ return nil
+ else
+ Thread.critical = old_critical
+ case block.arity
+ when 1 then yield(result)
+ else yield(result, extra_data)
+ end
+ end
+end
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