[Zope] Cool monkey patch to make tracebacks more useful :-)

[Dieter Maurer]

Lennart Regebro wrote at 2005-7-13 12:47 +0200:
> ...
>Ever noticed how it's near impossible to figure out what actually
>causes an error when you run functional tests? Can you fix that too?
>:-)

I solve this with a browser emulation that does not use HTTP for requests
but instead emulates "ZPublisher.Publish.publish" and therefore
can handle exceptions itself. It somehow looks like this:

  def _internalRequest(self, path, query, method, headers, request_params,
                       catch_exc, response,
                       ):
    '''perform a request against the internal *url*.'''
    from Zope import zpublisher_exception_hook as err_hook
    from Zope import zpublisher_validated_hook as validated_hook
    try:
      # Note: we should use the checkpoint feature, new in ZODB 3.3
      #  Unfortunately, we still use ZODB 3.2...
      #  Without this feature, we cannot reliably undo the effects
      #  of failed requests (we try with subtransactions)
      request = self._makeRequest(path, query, method, headers, request_params)
      zope_response = request.response
      object = request.traverse(request['PATH_INFO'].strip(),
                                validated_hook=validated_hook,
                                )
      result=mapply(object, request.args, request,
                    call_object,1,
                    missing_name,
                    dont_publish_class,
                    request, bind=1,
                    )
      if result is not zope_response: zope_response.setBody(result)
      get_transaction().commit(1)
    except:
      try:
        # Probably, we need special treatment for 'raise redirect'
        if not catch_exc or err_hook is None: raise
        response._setException()
        # we learned from Malcolm that 'err_hook' always raises an exception
        try:
          zope_response = err_hook(request['PARENTS'][0], *exc_info())
        except:
          # Note: we do not handle "Retry" (as it is very unlikely)
          zope_response.exception(*exc_info())
      finally: get_transaction().abort(1)
    response._setFromZope(zope_response)



-- 
Dieter