Sample Typescript + Express.js + Zod validation

This is a very minimal setup with Typescript, Express.js and Zod, to demonstrate how we can use validation in our requests.

Usage

1. Install everything: npm install
2. Setup basic .env file: echo PORT=3000 > .env
3. Start the app: npm start

Here are the endpoints and routes available for this app:

• GET /errors/not-found - returns a 404
• GET /errors/async-example - calls an async function that throws an exception
• GET /errors/server-unavailable - returns a 500
• POST /users/function - example of validation with Zod using a function
• POST /users/middleware - example of validation with Zod using middleware

Dev environment setup

Previously I used ts-node-dev, however that tool is unreliable. There are many different ways of setting up a Typescript node project that reloads on change, as described in the StackOverflow answer How to watch and reload TS Node when Typescript files change, and in the end I went with swc + ts-node + nodemon, which was setup like this:

1. Install nodemon: npm install --save-dev nodemon
2. Install ts-node and swc: npm install --save-dev ts-node @swc/core @swc/helpers regenerator-runtime
3. Add swc to tsconfig.json:

{
  "compilerOptions": {
    ...
  },
  "ts-node": {
    "swc": true
  }
}

4. Run with nodemon: nodemon --watch src src/index.ts