aws-sam-local-testing

Overview

AWS SAM Local is the canonical local-testing toolchain for AWS Lambda. Per docs.aws.amazon.com/serverless-application-model, it runs Lambdas in Docker containers locally with images that mirror the Lambda runtime - same Linux, same Node/Python/Java binaries, same handler-invocation contract.

When to use

• Local unit + integration tests for Lambda handlers.
• Testing API Gateway + Lambda routing locally.
• Reproducing prod Lambda behaviour without deploying.
• Event-payload-driven tests (S3 event, SQS message, API GW request).