This is the source code for the demo presented at AWS Summit Stockholm, MA-03: Supercharge your DevOps practice with a cloud-native, cloud-first approach.
The code is a simple example, but the patterns shown here are the ones we use on a day-to-day basis at Plain.
For a related blog post, have a read of our Magical AWS Serverless Developer Experience.
This is a simple API that is responsible for managing workspaces and customers. The data is stored in DynamoDB.
The API has 4 operations implemented:
- Create workspace
- Get workspace
- Create customer
- Get customer
The integration test runs against a deployed instance of the application without any mocks. This is referred to as "cloud-first" testing.
What this means is that we need to get an API Gateway URL to send our requests to. Due to Cloudformation having very low rate limits, we have a tiny script, cacheCloudformationOutputs.ts, that caches these outputs to file. When running tests in parallel this acts as a shared read cache.
The test code can then use getCloudformationOutputs.ts to get the API Gateway URL to send requests to. If you're testing other things like SQS, SNS, EventBridge, DynamoDB, etc. then you can apply a similar pattern of getting their ARNs or names.
The integration test we have written is the postCustomer.itest.ts, which has a few test cases.
We do the following three things to make writing tests easy:
- Have our domain layer "pure" of an API specific detail (for example that it runs in a Lambda). This allows us to invoke the domain layer in our tests and easily set up the required state before a test.
- Pass in all our dependencies to domain functions via
ctx. This makes it easy for tests to create a small test context with only the smallest amount of required dependencies. - Tests don't share state, we create a new workspace (tenant) in each test suite therefore allowing us to massively parallelize these tests.
The handler is responsible for doing some basic input validation for which we use zod.
We also use aws-lambda-powertools-typescript for our logging framework.
Our domain code uses on explicit error return types via true-myth, this makes it clear on the domain API that it can error and what those error cases are.
Required: Node.js 14
To install dependencies:
$ npm installAWS credentials need to be configured in your local environment.
Then to run the application in Live Lambda Development mode run:
$ npm run startStarts the local Lambda development environment.
Runs the integration tests that test against live AWS services.
Build your app and synthesize your stacks.
Generates a .build/ directory with the compiled files and a .build/cdk.out/ directory with the synthesized CloudFormation stacks.
Deploy all your stacks to AWS. Or optionally deploy a specific stack.
Remove all your stacks and all of their resources from AWS. Or optionally remove a specific stack.
We’re building the fastest way to provide amazing customer service. A tool that comes with modern defaults, an opinionated workflow and a lightning-fast UI — all backed by our powerful API.
Our vision is to build the go-to customer service infrastructure for the companies of the next decade.
Interested in using Plain or joining us on our mission? Check out www.plain.com!
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