Export the type of the handler of app.openapi() for better code organization

[lucafaggianelli]

Which middleware is the feature for?

@hono/zod-openapi

What is the feature you are proposing?

I would like to define routes and handlers in separate files for better organization and register them in a central file where I declare the app object.

Let's say I have the file routes/shorturls.ts:

export const createShortUrlRoute = createRoute({})

// What's the type of createShortUrlHandler ?
export const createShortUrlHandler = async (c) => {
  const data = c.req.valid('json');
}

and the main file index.ts where I declare the app and I register the routes:

import { OpenAPIHono } from "@hono/zod-openapi";

export const app = new OpenAPIHono();

// I would like to register the routes here
app.openapi(createShortUrlRoute, createShortUrlHandler)

The problem is the type of createShortUrlHandler, if I use a normal Handler type, I loose the request and response validation types, I tried also to reuse the types declared in the sourcecode of @hono/zod-openapi but basically I need to copy 100s of lines of code.

Proposed solution

Can you expose the type of the handler so I can do something like this:

import { OpenAPIHandler } from "@hono/zod-openapi";

export const createShortUrlRoute = createRoute({})

export const createShortUrlHandler: OpenAPIHandler<typeof createShortUrlRoute> = async (c) => {
  const data = c.req.valid('json');
}

Actual solution

Today I have my OpenAPIHono app defined in a dedicated app.ts file and I have multiple route files that import app and register the routes and finally all route files are imported into index.ts as import './routes/shorturls.ts'

[yusukebe]

Hi @lucafaggianelli

Thank you for the proposal. Is this like a createHandlers() exported from hono/factory in the plain hono case?

https://hono.dev/docs/helpers/factory#factory-createhandlers

[lucafaggianelli]

hi @yusukebe yes something like the createHanders would do, or even just a Typescript type OpenAPIHandler, the only difference with the plain createHanders is that in the case of @hono/zod-openapi I think it must include the route definition, something like:

createHanders<typeof routeDefinition>(async (c) => {})

PS: I'm happy to contribute to this feature with a PR

[yusukebe]

@lucafaggianelli

I like the following API!

createHanders<typeof routeDefinition>(async (c) => {})

Can you create a PR for it? Thanks!