1. AWS Lambda is commonly being used together with other AWS Services such as DynamoDB, S3 and SQS.
2. Conventional Python Unit Testing is not sufficient to perform unit test on AWS Lambda Python as it requires integration with AWS Services.

1. Provides an example how AWS Services (e.g. DynamoDB) can be mocked to allow Unit Testing on AWS Lambda Python.
2. Provides an example how AWS CDK is used together in this project as demostration of IAC together with AWS Lambda Python Source Code.

requirements-test.txt

pytest==6.2.5
pytest-cov==3.0.0
pytest-mock==3.8.2
requests-mock==1.10.0
moto[all]==4.0.1

python3 -m pytest lambda/functions_tests/*/test_*.py --capture=sys --cov=lambda/functions --cov-fail-under=95 --cov-report=term-missing

The cdk.json file tells the CDK Toolkit how to execute your app.

This project is set up like a standard Python project. The initialization process also creates a virtualenv within this project, stored under the .venv directory. To create the virtualenv it assumes that there is a python3 (or python for Windows) executable in your path with access to the venv package. If for any reason the automatic creation of the virtualenv fails, you can create the virtualenv manually.

To manually create a virtualenv on MacOS and Linux:

$ python3 -m venv .venv

After the init process completes and the virtualenv is created, you can use the following step to activate your virtualenv.

$ source .venv/bin/activate

If you are a Windows platform, you would activate the virtualenv like this:

% .venv\Scripts\activate.bat

Once the virtualenv is activated, you can install the required dependencies.

$ pip install -r requirements.txt

At this point you can now synthesize the CloudFormation template for this code.

$ cdk synth

To add additional dependencies, for example other CDK libraries, just add them to your setup.py file and rerun the pip install -r requirements.txt command.

• cdk ls list all stacks in the app
• cdk synth emits the synthesized CloudFormation template
• cdk deploy deploy this stack to your default AWS account/region
• cdk diff compare deployed stack with current state
• cdk docs open CDK documentation

Enjoy!