serverless-application-model VS jest

The complete solution with SAM is available here.

There are many options to deploy Serverless Applications in AWS and one of them is SAM, the Serverless Application Model. I chose to use it here, because it doesn't add too many layers of abstraction between what's being deployed and the code we write and our infrastructure is quite simple.

The solution uses AWS SAM with the global configuration for Lambda functions and the public API you can use to access Apache Zeppelin. The stack deployment provides the URL as an output value.

When you combine this with the AWS Serverless Application Model you can also very easily include your dependencies. Or use a compiled language like golang for your Lambda functions. You simply run sam build before you run the aws cloudformation package and aws cloudformation deploy commands. SAM will build the binary and update the template to point to the newly built binary. Package will then upload it to S3 and replace the local reference to the S3 location. Deploy can then create or update the stack or you can use the CloudFormation integration in CodePipeline.

I'm a big fan of using an Infrastructure as Code (IaC) approach for any project. My go to tools for this are the Servlerless Application Model (SAM) and it's associated CLI (SAM CLI). For more official use cases and for cross platform apps I typically use Terraform.

AWS SAM

Kicking off the tour and not starting a war, but I'm going to be using the Serverless Application Model.

The diagram here is super simple. I'm going to write something a little later that shows how this code could fit into a bigger workflow, but for now, I'm keeping it basic. And yes, that's the SAM Squirrel in there.

Interestingly, AWS CDK and SAM are both explicitly mentioned. While CDK broadly addresses Infrastructure as Code, SAM is highlighted for its role in developing serverless data pipelines - a hugely underrated concept.

Naturally, there are several options available to declare your cloud resources. The options with the most popularity are the CDK, AWS CloudFormation, SST, Serverless framework, Terraform, and AWS SAM. There are others, but when talking about Infrastructure as Code (IaC), these are the ones you hear about most often.

There are several testing approaches you can take to ascertain the functionality of the auth API. One way would be to automate the testing using unit tests with tools like Jest and Supertest. Alternatively, you can make use of API clients like Postman or the Thunder Client VS Code extension to test the API.

GitHub | Website

Jest

you have selected a testing framework. In my case, it's Jest with Supertest

Jest, created and maintained by Facebook, is a JavaScript testing framework with a focus on simplicity. It is often recognized for its zero-configuration setup and seamless integration, especially with React applications, making it a favored choice for developers in both small-scale projects and large enterprise applications.

Jest (https://jestjs.io/)

console.error Jest encountered an unexpected token Jest failed to parse a file. This happens e.g. when your code or its dependencies use non-standard JavaScript syntax, or when Jest is not configured to support such syntax. Out of the box Jest supports Babel, which will be used to transform your files into valid JS based on your Babel configuration. By default "node\_modules" folder is ignored by transformers. Here's what you can do: • If you are trying to use ECMAScript Modules, see https://jestjs.io/docs/ecmascript-modules for how to enable it. • If you are trying to use TypeScript, see https://jestjs.io/docs/getting-started#using-typescript • To have some of your "node\_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config. • If you need a custom transformation specify a "transform" option in your config. • If you simply want to mock your non-JS modules (e.g. binary assets) you can stub them out with the "moduleNameMapper" config option. You'll find more details and examples of these config options in the docs: https://jestjs.io/docs/configuration For information about custom transformations, see: https://jestjs.io/docs/code-transformation

Note: I will be using Jest as testing framework throughout the examples.

We use Jest Framework for testing. Jest is not a dogma, and, of course, in its place can be any other test runner, such as Mocha or Ava. Let's focus on tests. I'll provide a short example because I don’t want to waste your time. You can find the full version here. It's crucial to read the comments in the code below. Let's go!

Jest has long been my favorite got to test runner when it comes to UI unit and integration testing. With tools like React Testing Library (Testing Library framework for React) you get the benefit of very easy to write and maintain tests, as well as a quick and efficient way to run our tests.