Improve typescript types

[stuft2]

Problem

The OpenAPI Enforcer MiddlewareFunction and the Express RequestHandler / ErrorRequestHandler types are incompatible:

TS2345: Argument of type 'RequestHandler<ParamsDictionary, any, any, ParsedQs, Record<string, any>>' is not assignable to parameter of type 'MiddlewareFunction'.   Types of parameters 'req' and 'req' are incompatible.     Type '{}' is missing the following properties from type 'Request<ParamsDictionary, any, any, ParsedQs, Record<string, any>>': get, header, accepts, acceptsCharsets, and 77 more.

TS2322: Type 'ErrorRequestHandler >' is not assignable to type 'MiddlewareFunction'.

Reproduction

Typescript v4.2.2

import {RequestHandler, ErrorRequestHandler} from 'express'
import {MiddlewareFunction} from 'openapi-enforcer-middleware'

const expressMiddleware: RequestHandler = (req, res, next) => {}
const expressErrMiddleware: ErrorRequestHandler = (err, req, res, next) => {}

const enforcerMiddleware: MiddlewareFunction = expressMiddleware // TS2345 error occurs
const enfrorcerErrMiddleware: MiddlewareFunction = expressErrMiddleware // TS2322 error occurs

Solution Description

• Utilize the @types/express type definitions instead of similar custom types

If the Enforcer Middleware is built for Express, then we can safely assume the RequestHandler and ErrorRequestHandler types should be used instead of custom types.

Additional updates

• Improve the type inference of injected dependencies (see Tuples in rest parameters and spread expressions)
• Pass along the NextFunction type from express instead of a similar custom type
• Implements Controllers and ControllersMap types to avoid redundant declarations of Middleware and Controllers dictionaries

These updates remove most of the usages of the object type to narrow what types are and are not allowed. Additionally, the use of object is discouraged since it's usage is finicky. For example: ESLint bans Object and object types by default citing this Typescript Issue.

[Gi60s]

Please educate me on this one. Why <T extends unknown[]> instead of using any[]?

[stuft2]

The short answer is that any isn't type safe so I always default to using unknown instead of any. It's kind of like using const by default even though you could use let to declare all variables in javascript.

You can read more about unknown vs any on this stackoverflow answer or on the Typescript 3.0 RC.

[Gi60s]

Overall I love this PR, just that one question that I listed as a comment. Let me know the answer and I'll work on publishing this. Thank you.

[Gi60s]

Published to NPM as version 1.2.4.