test_lambda_funtion_mock.py

import boto3
import pytest
from lambda_function import *

class MockBotoSession:
    class Session:

        def client(self, service_name, region_name):
            # create a flexible Client class for any boto3 client
            class Client:
                def list_crawlers(self):
                    # hardcode the list_crawlers response
                    return {'CrawlerNames': ['crawler_1', 'crawler_2',]}

            return Client()
          
          
def test_lambda_handler(monkeypatch):
  
  # patch boto session with a mock client
  monkeypatch.setattr(boto3, 'session', MockBotoSession)
  
  response = lambda_handler(event=test_event, context={})
  assert response == 'something'