Zod - Firebase

By combining Zod with Firestore’s `withConverter` API, you can enforce type safety at the boundary between your app and the database.

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Introduction

Firebase - Firestore is a powerful, flexible NoSQL database — but with great flexibility comes the risk of subtle data shape bugs, especially in TypeScript projects where runtime and compile-time types can easily diverge.

Firestore’s SDKs is powerful, but they don’t enforce your TypeScript types at runtime.

That means you can write code like this:

type User = { name: string; age: number }
const user: User = await getDoc(docRef).then((doc) => doc.data() as User)

But if Firestore contains { name: "Alice" }, you won’t know until much later that age is missing.

This can lead to subtle bugs and runtime errors.

FirestoreDataConverter

Create a new project:

deno run -A npm:create-vite@latest zod-firebase --template react-ts --allow-scripts
cd zod-firebase
deno install --allow-scripts --node-modules-dir --npm firebase tailwindcss @tailwindcss/vite

Zod lets you define runtime schemas that mirror your TypeScript interfaces.

import { z } from 'zod'


export const UserSchema = z.object({
  name: z.string(),
  age: z.number(),
})
export type User = z.infer<typeof UserSchema>

Pending