fix(event-handler): allow for @app.not_found() decorator

Changes: - allow for `@app.not_found()` decorator - add typing to `strtobool` and add code coverage

aws_lambda_powertools/event_handler/api_gateway.py

@@ -579,7 +579,7 @@ def _remove_prefix(self, path: str) -> str:
  @staticmethod
  def _path_starts_with(path: str, prefix: str):
  """Returns true if the `path` starts with a prefix plus a `/`"""
- if not isinstance(prefix, str) or len(prefix) == 0:
+ if not isinstance(prefix, str) or prefix == "":
  return False
 
  return path.startswith(prefix + "/")
@@ -633,7 +633,9 @@ def _call_route(self, route: Route, args: Dict[str, str]) -> ResponseBuilder:
 
  raise
 
- def not_found(self, func: Callable):
+ def not_found(self, func: Optional[Callable] = None):
+ if func is None:
+ return self.exception_handler(NotFoundError)
  return self.exception_handler(NotFoundError)(func)
 
  def exception_handler(self, exc_class: Type[Exception]):

aws_lambda_powertools/shared/functions.py

@@ -1,14 +1,13 @@
 from typing import Any, Optional, Union
 
 
-def strtobool(value):
+def strtobool(value: str) -> bool:
  value = value.lower()
  if value in ("y", "yes", "t", "true", "on", "1"):
- return 1
- elif value in ("n", "no", "f", "false", "off", "0"):
- return 0
- else:
- raise ValueError("invalid truth value %r" % (value,))
+ return True
+ if value in ("n", "no", "f", "false", "off", "0"):
+ return False
+ raise ValueError(f"invalid truth value '{value}'")
 
 
 def resolve_truthy_env_var_choice(env: str, choice: Optional[bool] = None) -> bool:

tests/functional/event_handler/test_api_gateway.py

@@ -1142,10 +1142,26 @@ def handle_not_found(exc: NotFoundError) -> Response:
  return Response(status_code=404, content_type=content_types.TEXT_PLAIN, body="I am a teapot!")
 
  # WHEN calling the event handler
- # AND not route is found
+ # AND no route is found
  result = app(LOAD_GW_EVENT, {})
 
  # THEN call the exception_handler
  assert result["statusCode"] == 404
  assert result["headers"]["Content-Type"] == content_types.TEXT_PLAIN
  assert result["body"] == "I am a teapot!"
+
+
+def test_exception_handler_not_found_alt():
+ # GIVEN a resolver with `@app.not_found()`
+ app = ApiGatewayResolver()
+
+ @app.not_found()
+ def handle_not_found(_) -> Response:
+ return Response(status_code=404, content_type=content_types.APPLICATION_JSON, body="{}")
+
+ # WHEN calling the event handler
+ # AND no route is found
+ result = app(LOAD_GW_EVENT, {})
+
+ # THEN call the @app.not_found() function
+ assert result["statusCode"] == 404

tests/functional/test_shared_functions.py

@@ -1,4 +1,6 @@
-from aws_lambda_powertools.shared.functions import resolve_env_var_choice, resolve_truthy_env_var_choice
+import pytest
+
+from aws_lambda_powertools.shared.functions import resolve_env_var_choice, resolve_truthy_env_var_choice, strtobool
 
 
 def test_resolve_env_var_choice_explicit_wins_over_env_var():
@@ -9,3 +11,19 @@ def test_resolve_env_var_choice_explicit_wins_over_env_var():
 def test_resolve_env_var_choice_env_wins_over_absent_explicit():
  assert resolve_truthy_env_var_choice(env="true") == 1
  assert resolve_env_var_choice(env="something") == "something"
+
+
+@pytest.mark.parametrize("true_value", ["y", "yes", "t", "true", "on", "1"])
+def test_strtobool_true(true_value):
+ assert strtobool(true_value)
+
+
+@pytest.mark.parametrize("false_value", ["n", "no", "f", "false", "off", "0"])
+def test_strtobool_false(false_value):
+ assert strtobool(false_value) is False
+
+
+def test_strtobool_value_error():
+ with pytest.raises(ValueError) as exp:
+ strtobool("fail")
+ assert str(exp.value) == "invalid truth value 'fail'"