Handle Restify endpoints as Observables using RxJS

createRequestHandler.ts

import { Observable, Subscription } from 'rxjs'
import {
    Request,
    Response,
    Next
} from 'restify'

export interface RequestContext {
    req: Request,
    res: Response,
    next: Next
}

export type RequestHandler = (
    context: Observable<RequestContext>
) => Observable<any>


export function createHandler (fn: RequestHandler ) {
    return (
        req: Request,
        res: Response,
        next: Next
    ) =>
        fn( Observable.of<RequestContext>({ req, res, next }) )
            .catch( err => Observable.of(err) )
            .take(1)
            .subscribe( result => {
                res.send(result)
                next()
            } )
}