@foodsy-app/fastify-typebox

@foodsy-app/fastify-typebox

Plugin for Fastify to prevent having to write duplicate type definitions for schemas.

@foodsy-app/fastify-typebox uses typebox, to compose JSON schemas.

Important note before using this plugin!

This plugin requires patch-package to comment existing type declarations for request methods in node_modules/fastify/types/instance.d.ts since TypeScript does not allow to overwrite declarations.

Create a fastify+3.1.1.patch file (edit the version based on the Fastify version you have installed) and paste the block below inside:

diff --git a/node_modules/fastify/types/instance.d.ts b/node_modules/fastify/types/instance.d.ts
index 06380bd..558338d 100644
--- a/node_modules/fastify/types/instance.d.ts
+++ b/node_modules/fastify/types/instance.d.ts
@@ -66,14 +66,14 @@ export interface FastifyInstance<
     ContextConfig = ContextConfigDefault
   >(opts: RouteOptions<RawServer, RawRequest, RawReply, RouteGeneric, ContextConfig>): FastifyInstance<RawServer, RawRequest, RawReply, Logger>;

-  get: RouteShorthandMethod<RawServer, RawRequest, RawReply>;
-  head: RouteShorthandMethod<RawServer, RawRequest, RawReply>;
-  post: RouteShorthandMethod<RawServer, RawRequest, RawReply>;
-  put: RouteShorthandMethod<RawServer, RawRequest, RawReply>;
-  delete: RouteShorthandMethod<RawServer, RawRequest, RawReply>;
-  options: RouteShorthandMethod<RawServer, RawRequest, RawReply>;
-  patch: RouteShorthandMethod<RawServer, RawRequest, RawReply>;
-  all: RouteShorthandMethod<RawServer, RawRequest, RawReply>;
+  // get: RouteShorthandMethod<RawServer, RawRequest, RawReply>;
+  // head: RouteShorthandMethod<RawServer, RawRequest, RawReply>;
+  // post: RouteShorthandMethod<RawServer, RawRequest, RawReply>;
+  // put: RouteShorthandMethod<RawServer, RawRequest, RawReply>;
+  // delete: RouteShorthandMethod<RawServer, RawRequest, RawReply>;
+  // options: RouteShorthandMethod<RawServer, RawRequest, RawReply>;
+  // patch: RouteShorthandMethod<RawServer, RawRequest, RawReply>;
+  // all: RouteShorthandMethod<RawServer, RawRequest, RawReply>;

   // addHook: overloads

After this, run the following command:

npx patch-package --patch-dir .

Run the same command using the --reverse flag if you notice any problems.

Install

npm i @foodsy-app/fastify-typebox @sinclair/typebox
# Or if you are using Yarn
yarn add @foodsy-app/fastify-typebox @sinclair/typebox

Usage

Add it to your project using register and you are done!

import fastify from "fastify";

fastify.register(require("@foodsy-app/fastify-typebox"));

Examples

This plugin exposes a new method on the FastifyInstance called typeboxSchema

Basic usage

Notice: Please refer to the typebox repository for a overview of the typebox API.

import { Type } from "@sinclair/typebox";

// Available request methods are
// .get, .head, .post, .put, .delete, .options, .patch and .all
server.get(
  "/secret-route/:id",
  {
    schema: server.typeboxSchema({
      // You can also type querystring, headers and response
      params: Type.Object({
        id: Type.String(),
      }),
      body: Type.Object({
        user: Type.Object({
          name: Type.String(),
          age: Type.Number({ minimum: 18 }),
        }),
      }),
    }),
  },
  (request, reply) => {
    // `id` is inferred as string | undefined
    const id = request.params?.id;

    // `user` is inferred as the object we described!
    const user = request.body?.user;
  }
);