feat: add grpc transcoding + tests

google/api_core/path_template.py

@@ -64,7 +64,7 @@ def _expand_variable_match(positional_vars, named_vars, match):
  """Expand a matched variable with its value.
 
  Args:
- positional_vars (list): A list of positonal variables. This list will
+ positional_vars (list): A list of positional variables. This list will
  be modified.
  named_vars (dict): A dictionary of named variables.
  match (re.Match): A regular expression match.
@@ -193,3 +193,61 @@ def validate(tmpl, path):
  """
  pattern = _generate_pattern_for_template(tmpl) + "$"
  return True if re.match(pattern, path) is not None else False
+
+
+def transcode(http_options, **request_kwargs):
+ """Transcodes a grpc request pattern into a proper HTTP request following the rules outlined here,
+ https://github.com/googleapis/googleapis/blob/master/google/api/http.proto#L44-L312
+
+ Args:
+ http_options (list(dict)): A list of dicts which consist of these keys,
+ 'method' (str): The http method
+ 'uri' (str): The path template
+ 'body' (str): The body field name (optional)
+ (This is a simplified representation of the proto option `google.api.http`)
+ request_kwargs (dict) : A dict representing the request object
+
+ Returns:
+ dict: The transcoded request with these keys,
+ 'method' (str) : The http method
+ 'uri' (str) : The expanded uri
+ 'body' (dict) : A dict representing the body (optional)
+ 'query_params' (dict) : A dict mapping query parameter variables and values
+
+ Raises:
+ ValueError: If the request does not match the given template.
+ """
+ answer = {}
+ for http_option in http_options:
+
+ # Assign path
+ uri_template = http_option["uri"]
+ path_fields = [
+ match.group("name") for match in _VARIABLE_RE.finditer(uri_template)
+ ]
+ path_args = {field: request_kwargs.get(field, None) for field in path_fields}
+ leftovers = {k: v for k, v in request_kwargs.items() if k not in path_args}
+ answer["uri"] = expand(uri_template, **path_args)
+
+ if not validate(uri_template, answer["uri"]) or not all(path_args.values()):
+ continue
+
+ # Assign body and query params
+ body = http_option.get("body")
+
+ if body:
+ if body == "*":
+ answer["body"] = leftovers
+ answer["query_params"] = {}
+ else:
+ try:
+ answer["body"] = leftovers.pop(body)
+ except KeyError:
+ continue
+ answer["query_params"] = leftovers
+ else:
+ answer["query_params"] = leftovers
+ answer["method"] = http_option["method"]
+ return answer
+
+ raise ValueError("Request obj does not match any template")

tests/unit/test_path_template.py

@@ -113,3 +113,161 @@ def test__replace_variable_with_pattern():
  match.group.return_value = None
  with pytest.raises(ValueError, match="Unknown"):
  path_template._replace_variable_with_pattern(match)
+
+
+@pytest.mark.parametrize(
+ "http_options, request_kwargs, expected_result",
+ [
+ [
+ [["get", "/v1/no/template", ""]],
+ {"foo": "bar"},
+ ["get", "/v1/no/template", {}, {"foo": "bar"}],
+ ],
+ # Single templates
+ [
+ [["get", "/v1/{field}", ""]],
+ {"field": "parent"},
+ ["get", "/v1/parent", {}, {}],
+ ],
+ [
+ [["get", "/v1/{field.sub}", ""]],
+ {"field.sub": "parent", "foo": "bar"},
+ ["get", "/v1/parent", {}, {"foo": "bar"}],
+ ],
+ # Single segment wildcard
+ [
+ [["get", "/v1/{field=*}", ""]],
+ {"field": "parent"},
+ ["get", "/v1/parent", {}, {}],
+ ],
+ [
+ [["get", "/v1/{field=a/*/b/*}", ""]],
+ {"field": "a/parent/b/child", "foo": "bar"},
+ ["get", "/v1/a/parent/b/child", {}, {"foo": "bar"}],
+ ],
+ # Double segment wildcard
+ [
+ [["get", "/v1/{field=**}", ""]],
+ {"field": "parent/p1"},
+ ["get", "/v1/parent/p1", {}, {}],
+ ],
+ [
+ [["get", "/v1/{field=a/**/b/**}", ""]],
+ {"field": "a/parent/p1/b/child/c1", "foo": "bar"},
+ ["get", "/v1/a/parent/p1/b/child/c1", {}, {"foo": "bar"}],
+ ],
+ # Combined single and double segment wildcard
+ [
+ [["get", "/v1/{field=a/*/b/**}", ""]],
+ {"field": "a/parent/b/child/c1"},
+ ["get", "/v1/a/parent/b/child/c1", {}, {}],
+ ],
+ [
+ [["get", "/v1/{field=a/**/b/*}/v2/{name}", ""]],
+ {"field": "a/parent/p1/b/child", "name": "first", "foo": "bar"},
+ ["get", "/v1/a/parent/p1/b/child/v2/first", {}, {"foo": "bar"}],
+ ],
+ # Single field body
+ [
+ [["post", "/v1/no/template", "data"]],
+ {"data": {"id": 1, "info": "some info"}, "foo": "bar"},
+ ["post", "/v1/no/template", {"id": 1, "info": "some info"}, {"foo": "bar"}],
+ ],
+ [
+ [["post", "/v1/{field=a/*}/b/{name=**}", "data"]],
+ {
+ "field": "a/parent",
+ "name": "first/last",
+ "data": {"id": 1, "info": "some info"},
+ "foo": "bar",
+ },
+ [
+ "post",
+ "/v1/a/parent/b/first/last",
+ {"id": 1, "info": "some info"},
+ {"foo": "bar"},
+ ],
+ ],
+ # Wildcard body
+ [
+ [["post", "/v1/{field=a/*}/b/{name=**}", "*"]],
+ {
+ "field": "a/parent",
+ "name": "first/last",
+ "data": {"id": 1, "info": "some info"},
+ "foo": "bar",
+ },
+ [
+ "post",
+ "/v1/a/parent/b/first/last",
+ {"data": {"id": 1, "info": "some info"}, "foo": "bar"},
+ {},
+ ],
+ ],
+ # Additional bindings
+ [
+ [
+ ["post", "/v1/{field=a/*}/b/{name=**}", "extra_data"],
+ ["post", "/v1/{field=a/*}/b/{name=**}", "*"],
+ ],
+ {
+ "field": "a/parent",
+ "name": "first/last",
+ "data": {"id": 1, "info": "some info"},
+ "foo": "bar",
+ },
+ [
+ "post",
+ "/v1/a/parent/b/first/last",
+ {"data": {"id": 1, "info": "some info"}, "foo": "bar"},
+ {},
+ ],
+ ],
+ [
+ [
+ ["get", "/v1/{field=a/*}/b/{name=**}", ""],
+ ["get", "/v1/{field=a/*}/b/first/last", ""],
+ ],
+ {"field": "a/parent", "foo": "bar"},
+ ["get", "/v1/a/parent/b/first/last", {}, {"foo": "bar"}],
+ ],
+ ],
+)
+def test_transcode(http_options, request_kwargs, expected_result):
+ http_options, expected_result = helper_test_transcode(http_options, expected_result)
+ result = path_template.transcode(http_options, **request_kwargs)
+ assert result == expected_result
+
+
+@pytest.mark.parametrize(
+ "http_options, request_kwargs",
+ [
+ [[["get", "/v1/{name}", ""]], {"foo": "bar"}],
+ [[["get", "/v1/{name}", ""]], {"name": "first/last"}],
+ [[["get", "/v1/{name=mr/*/*}", ""]], {"name": "first/last"}],
+ [[["post", "/v1/{name}", "data"]], {"name": "first/last"}],
+ ],
+)
+def test_transcode_fails(http_options, request_kwargs):
+ http_options, _ = helper_test_transcode(http_options, range(4))
+ with pytest.raises(ValueError):
+ path_template.transcode(http_options, **request_kwargs)
+
+
+def helper_test_transcode(http_options_list, expected_result_list):
+ http_options = []
+ for opt_list in http_options_list:
+ http_option = {"method": opt_list[0], "uri": opt_list[1]}
+ if opt_list[2]:
+ http_option["body"] = opt_list[2]
+ http_options.append(http_option)
+
+ expected_result = {
+ "method": expected_result_list[0],
+ "uri": expected_result_list[1],
+ "query_params": expected_result_list[3],
+ }
+ if expected_result_list[2]:
+ expected_result["body"] = expected_result_list[2]
+
+ return (http_options, expected_result)