typera-openapi

typera-openapi - typera to OpenAPI generator

typera-openapi is an experimental tool that creates OpenAPI v3 definitions from a project that uses typera for routes.

Getting started

Install typera-openapi:

npm install typera-openapi

Your route files must have a single default export that exports a typera router. JSDoc comments serve as additional documentation:

import { Route, route, router } from 'typera-express'

/**
 * The JSDoc text is used as a description for the route (optional).
 *
 * @response 200 Success response description.
 * @response 400 Another description for a response. This one
 * spans multile lines.
 */
const myRoute: Route<Response.Ok<string> | Response.BadRequest<string>> =
  route.get(...).handler(...)

// ...

export default router(myRoute, ...)

In the OpenAPI v3 spec, the description field of a Response Object is required, so typera-openapi prints a warning if a JSDoc tag for a response is not found.

Run the typera-openapi tool giving paths to your route files as command line arguments. Assuming you have two route files in your project:

npx typera-openapi src/routes/foo.ts src/routes/bar.ts

This creates src/routes/foo.openapi.ts and src/routes/bar.openapi.ts which contain the OpenAPI definitions.

Use the definitions in your app to serve documentation:

// This is src/app.ts
import * as express from 'express'
import { OpenAPIV3 } from 'openapi-types'
import * as swaggerUi from 'swagger-ui-express'
import { prefix } from 'typera-openapi'

import foo from './routes/foo'
import fooDefs from './routes/foo.openapi'
import bar from './routes/bar'
import barDefs from './routes/bar.openapi'

const openapiDoc: OpenAPIV3.Document = {
  openapi: '3.0.0',
  info: {
    title: 'My cool API',
    version: '0.1.0',
  },
  paths: {
    ...prefix('/foo', fooDefs.paths),
    ...prefix('/bar', barDefs.paths),
  },
}

const app = express()
app.use('/foo', foo.handler())
app.use('/bar', bar.handler())
app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(openapiDoc))

app.listen(3000, () => {
  console.log('Listening on 127.0.0.1:3000')
})

The prefix function is used to move OpenAPI path definitions to a different prefix, because the foo and bar routes are served from their respecive prefixes.