Lightning fast & simple Typescript Serverless builds

☁️ Founder & Dev @ Elva 🐦 Tweets serverless, memes & AWS 🍝 92% carbonara by now 🏗 AWS Community Builder

Demo Project

Let's start in an empty folder by running npm init -y to initialize a new project. Next, we create a function that will act as our Lambda handler, in src/function.ts:

// src/function.ts export const handler = async (event) => { console.log(event); return { status: 200 }; };

Now since we'll be using Serverless and esbuild to package and deploy our app, we'll need to install Serverless and the Serverless esbuild plugin: npm install serverless serverless-esbuild --save-dev

Finally, to deploy our app all we need to do is create a serverless.yml

# serverless.yml service: esbuild-demo plugins: - serverless-esbuild provider: name: aws runtime: nodejs14.x functions: function: handler: src/function.handler

and now we can run npx serverless deploy to get our app up and running in AWS - transpiled, three shaken & ready to rock. No additional configuration is necessary but you can of course choose to configure esbuilds behavior if needed. The transpile target is chosen automatically from the Lambda runtime from the Serverless provider setting, but it will also automatically discover and respect tsconfig.json if you have it.

Setting up unit testing with Jest is almost just as simple. First, we need to add Jest, Jest types, and the Jest esbuild transformer:

npm install jest esbuild-jest @types/jest --save-dev

and then configure Jest to use the esbuild transformer:

// jest.config.json { "transform": { "^.+\\.(j|t)sx?$": "esbuild-jest" } }

We can now also write Typescript unit tests:

// tests/function.test.ts import { handler } from '../src/function'; describe('[function]', () => { it('should return status 200', async () => { const res = await handler(null) expect(res).toEqual({ status: 200 }); }); });

and run them with npx jest!

Summary

Having migrated a few more or less complicated projects from Webpack setups, esbuild tend to "just work" every time as a drop-in replacement. It provides significantly faster builds all while requiring a fraction of the config! 🚀

You can find the complete demo project here!

If you enjoyed this post and want to see more, follow me on Twitter at @TastefulElk where I frequently write about serverless tech, AWS, and developer productivity!

Lightning fast & simple Typescript Serverless builds

Comments

More from this blog

Radical Simplicity in Cloud Architecture

Testing Individual StepFunction States

💸 How to save thousands of dollars on AWS WAF

⚡️Serverless Frameworks for 2023

Separate stateful infrastructure with Serverless Compose

Demo Project

Summary

Command Palette

Comments

More from this blog

Demo Project

Summary