+import collections
+from wsgiref.util import setup_testing_defaults
+
+Request = collections.namedtuple(
+ 'Request',
+ [
+ 'method',
+ 'path',
+ 'content_type',
+ 'content_length',
+ 'content',
+ 'headers',
+ 'environment',
+ ],
+)
+
+def _environment_to_headers(environment):
+ result = collections.OrderedDict()
+
+ for key, value in environment.items():
+ if key.startswith('HTTP_'):
+ key = key[len('HTTP_'):].lower()
+ result[key.lower()] = value
+
+ return result
+
+def request(method, path, **kwargs):
+ return Request(
+ method = method,
+ path = path,
+ content_type = kwargs.get('content_type', 'text/plain'),
+ content_length = kwargs.get('content_length', 0),
+ content = kwargs.get('content', ''),
+ headers = kwargs.get('headers', collections.OrderedDict()),
+ environment = kwargs.get('environment', {}),
+ )
+
+Response = collections.namedtuple(
+ 'Response',
+ [
+ 'status',
+ 'headers',
+ 'content',
+ 'encoding',
+ ],
+)
+
+def response(**kwargs):
+ return Response(
+ status = kwargs.get('status', 200),
+ headers = kwargs.get('headers', [('Content-type', 'text/plain; charset=utf-8')]),
+ content = kwargs.get('content', ''),
+ encoding = kwargs.get('encoding', 'utf-8'),
+ )
+
+# From https://www.iana.org/assignments/http-status-codes/http-status-codes.xhtml
+_STATUS_CODES_TO_STRINGS = {
+ 200: '200 OK',
+ 404: '404 Not Found',
+ 405: '405 Method Not Allowed',
+}
+
+def _status_code_to_string(status_code):
+ return _STATUS_CODES_TO_STRINGS[status_code]
+
+def _wrap_content(content_iterator, encoding):
+ if isinstance(content_iterator, str):
+ content_iterator = content_iterator.encode(encoding)
+ yield content_iterator
+ return
+
+ if isinstance(content_iterator, bytes):
+ yield content_iterator
+ return
+
+ for content_item in content_iterator:
+ if isinstance(content_item, str):
+ yield content_item.encode(encoding)
+
+ else:
+ yield content_item
+
+def application(request_handler):
+ def wrapped_request_handler(environment, start_response):
+ setup_testing_defaults(environment)
+
+ content_type = environment['CONTENT_TYPE']
+ content_length = environment['CONTENT_LENGTH']
+
+ if environment['CONTENT_LENGTH'] == '':
+ content_length = 0
+ content = ''
+
+ else:
+ content_length = int(environment['CONTENT_LENGTH'])
+ content = environment['wsgi.input'].read(content_length)
+
+ if content_length == '':
+ content_length = len(content)
+
+ else:
+ content_length = int(content_length)
+
+ result = request_handler(request(
+ environment['REQUEST_METHOD'],
+ environment['PATH_INFO'],
+ content_type = content_type,
+ content_length = content_length,
+ content = content,
+ headers = _environment_to_headers(environment),
+ environment = environment,
+ ))
+
+ start_response(
+ _status_code_to_string(result.status),
+ result.headers,
+ )
+
+ return _wrap_content(result.content, result.encoding)
+
+ return wrapped_request_handler
+
+def _route_matcher(route):
+ def matcher(path):
+ if route == path:
+ return True, ()
+
+ return False, None
+
+ return matcher
+
+def path_router(*routes_to_handlers, **kwargs):
+ matchers_to_handlers = []
+
+ for route, handler in routes_to_handlers:
+ matcher = _route_matcher(route)
+ matchers_to_handlers.append((matcher, handler))
+
+ defined_routes = [route for route, handler in routes_to_handlers]
+ def default_not_found_handler(request):
+ content = 'FILE {} NOT FOUND\n'.format(request.path)
+ content += 'The following routes are defined for this router:\n'
+ content += '\n'.join(defined_routes)
+ return response(status = 404, content = content)
+
+ not_found_handler = kwargs.pop('not_found_handler', default_not_found_handler)
+
+ if any(kwargs):
+ raise Exception('Unexpected keyword argument "{}"'.format(list(kwargs.keys())[0]))
+
+ def route(request):
+ for matcher, handler in matchers_to_handlers:
+ matched, args = matcher(request.path)
+ if matched:
+ return handler(request, *args)
+
+ return not_found_handler(request)
+
+ return route
+
+# https://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html
+_REQUEST_METHODS = ['OPTIONS', 'GET', 'HEAD', 'POST', 'PUT', 'DELETE', 'TRACE', 'CONNECT']
+
+def method_router(**kwargs):
+ allowed_methods = {}
+
+ for request_method in _REQUEST_METHODS:
+ if request_method in kwargs:
+ allowed_methods[request_method] = kwargs.pop(request_method)
+
+ auto_options = kwargs.pop('auto_options', True)
+
+ def default_options_handler(request):
+ return response(
+ status = 200,
+ headers = [
+ ('Allow', ', '.join(allowed_methods.keys())),
+ ('Content-Length', '0'),
+ ],
+ )
+
+ if auto_options and 'OPTIONS' not in allowed_methods:
+ allowed_methods['OPTIONS'] = default_options_handler
+
+ def default_method_not_allowed_handler(request):
+ content = 'METHOD "{}" NOT ALLOWED\n'.format(request.method)
+ content += 'The following methods are allowed for this resource:\n'
+ content += '\n'.join(allowed_methods.keys())
+ return response(status = 405, content = content)
+
+ method_not_allowed_handler = kwargs.pop(
+ 'method_not_allowed_handler',
+ default_method_not_allowed_handler,
+ )
+
+ if any(kwargs):
+ raise Exception('Unexpected keyword argument "{}"'.format(list(kwargs.keys())[0]))
+
+ def route(request):
+ return allowed_methods.get(request.method, method_not_allowed_handler)(request)
+
+ return route
+
+
+if __name__ == '__main__':
+ import unittest
+ from unittest import mock
+
+ class PathRouterTests(unittest.TestCase):
+ def test_routes_to_handler(self):
+ path = '/path'
+ expected_request = request('GET', path)
+ expected_response = response(content = 'Expected')
+ handler = mock.MagicMock()
+ handler.return_value = expected_response
+
+ router = path_router(
+ ('/path', handler),
+ )
+ actual_response = router(expected_request)
+
+ handler.assert_called_with(expected_request)
+ self.assertEqual(expected_response, actual_response)
+
+ def test_routes_to_first_matching_handler(self):
+ path = '/path'
+ expected_request = request('GET', path)
+ expected_response = response(content = 'Expected')
+ expected_handler = mock.MagicMock()
+ expected_handler.return_value = expected_response
+ unexpected_handler = mock.MagicMock()
+
+ router = path_router(
+ ('/path', expected_handler),
+ ('/path', unexpected_handler),
+ )
+ actual_response = router(expected_request)
+
+ expected_handler.assert_called_with(expected_request)
+ self.assertEqual(expected_response, actual_response)
+
+ unittest.main()
projects / sandbox / commitdiff