Function validator

Lib/wsgiref/validate.py:136–189

When applied between a WSGI server and a WSGI application, this middleware will check for WSGI compliance on a number of levels. This middleware does not modify the request or response in any way, but will raise an AssertionError if anything seems off (except for a failure to cl

(application)

        "{0} must be of type str (got {1})".format(title, repr(value)))

def validator(application):

    """
    When applied between a WSGI server and a WSGI application, this
    middleware will check for WSGI compliance on a number of levels.
    This middleware does not modify the request or response in any
    way, but will raise an AssertionError if anything seems off
    (except for a failure to close the application iterator, which
    will be printed to stderr -- there's no way to raise an exception
    at that point).
    """

    def lint_app(*args, **kw):
        assert_(len(args) == 2, "Two arguments required")
        assert_(not kw, "No keyword arguments allowed")
        environ, start_response = args

        check_environ(environ)

        # We use this to check if the application returns without
        # calling start_response:
        start_response_started = []

        def start_response_wrapper(*args, **kw):
            assert_(len(args) == 2 or len(args) == 3, (
                "Invalid number of arguments: %s" % (args,)))
            assert_(not kw, "No keyword arguments allowed")
            status = args[0]
            headers = args[1]
            if len(args) == 3:
                exc_info = args[2]
            else:
                exc_info = None

            check_status(status)
            check_headers(headers)
            check_content_type(status, headers)
            check_exc_info(exc_info)

            start_response_started.append(None)
            return WriteWrapper(start_response(*args))

        environ['wsgi.input'] = InputWrapper(environ['wsgi.input'])
        environ['wsgi.errors'] = ErrorWrapper(environ['wsgi.errors'])

        iterator = application(environ, start_response_wrapper)
        assert_(iterator is not None and iterator != False,
            "The application must return an iterator, if only an empty list")

        check_iterator(iterator)

        return IteratorWrapper(iterator, start_response_started)

    return lint_app

class InputWrapper: