simple-decor

simple-decor

Purpose

Modern REST API frameworks allow simple syntax to register new routes and type check their data transfer object (DTO). In express, these processes can be verbose, but migrating to newer frameworks is not always an option.

The goal of simple-decor is to bring in uncomplicated decorator-based route registration and DTO type checking to Express projects. Additionally, it plans to include automatic OpenAPI documentation generation in upcoming versions.

Installation

Using npm:

$ npm i simple-decor

Usage

Register a POST company/:companyId/user and DTO type checking using controller decorators

import { Post, ParamIsInt, BodyIsClass } from "simple-decor";

class UserController {
  @Post("company/:companyId/user")
  @ParamIsInt("companyId")
  @BodyIsClass(PostUserBody)
  post(req: Request, res: Response) {
    const { email, name } = req.body as PostUserBody;

    //create user ...

    res.send(200);
  }
}

Add registered routes to express application

import { setup } from "simple-decor";

const app = express();
app.listen(3000);
setup(app);

Decorators

Route registration

Decorator	Parameters	Description
Get	path string	Registers a new GET route
Patch	path string	Registers a new PATCH route
Post	path string	Registers a new POSTroute
Put	path string	Registers a new PUT route
Delete	path string	Registers a new DELETE route

Path param type checking

Decorator	Parameters	Description
ParamExists	name:string	Throws error if http request does not contains a path parameter with given name
ParamIsInt	name:string	Throws error if http request does not contains a path parameter with given name that contains only digits
ParamIsEmail	name:string	Throws error if http request does not contains a path parameter with given name that loosely matches an email
ParamIsEnum	name:string, enum:enum	Throws error if http request does not contains a path parameter with given name that is in the given enum

Query param type checking

Decorator	Parameters	Description
QueryExists	name:string	Throws error if http request does not contains a query parameter with given name
QueryIsInt	name:string	Throws error if http request does not contains a query parameter with given name that contains only digits
QueryIsEmail	name:string	Throws error if http request does not contains a query parameter with given name that loosely matches an email
QueryIsEnum	name:string, enum:enum	Throws error if http request does not contains a query parameter with given name that is in the given enum

Body type checking

Decorator	Parameters	Description
BodyIsClass	bodyClass: class	Throws error if http reqest body does not match the given class (class must be annotated with class-validator and class-transformer decorators