New testing utility #1169
Description
Original author: @beanaroo
Runtime: Python
Is your feature request related to a problem? Please describe
As per this discussion, creating test events for Lambda event sources is a laborious process.
Finding the correct event with default values tend to be 1/ invoking a Lambda function, 2/ logging the event, 3/ extracting the log event from CloudWatch, 4/ serializing back to native Python object, 5/ creating a Pytest fixture that can be used across tests.
NOTE: When the event source is supported by SAM CLI, this cycle can be shortened with
sam local generate-eventsub-command
This cycle repeats when you're trying to mock Lambda Context for libraries and middlewares that make use of it.
Describe the solution you'd like
Make tests events available in the project as Dataclasses that can be initialized with default values and changed as we see please.
from aws_lambda_powertools.utilities.testing import LambdaContext, ApiGatewayProxyEvent
import app
def test_handler():
app.handler(event=ApiGatewayProxyEvent(), context=LambdaContext())Describe alternatives you've considered
Create my own default Lambda Context using LambdaContext typing
import pytest
from aws_lambda_powertools.utilities.typing import LambdaContext
class MockLambdaContext(LambdaContext):
def __init__(self):
self._function_name = 'test-fn'
self._memory_limit_in_mb = 128
self._invoked_function_arn = 'arn:aws:lambda:us-east-1:12345678:function:test-fn'
self._aws_request_id = '52fdfc07-2182-154f-163f-5f0f9a621d72'
@pytest.fixture
def lambda_context() -> LambdaContext:
return MockLambdaContext()
def test_handler(lambda_context):
app.handler(event={}, context=lambda_context)If you provide guidance, is this something you'd like to contribute?
Additional context