functional-express

Functional helpers for dealing with Express.js routes. Provides a cleaner API for dealing with extracting request values and completing responses.

Installation

Using npm:

$ npm install functional-express

Using yarn:

$ yarn add functional-express

Usage

Completers

Completers fulfill the response of a request.

async

The async completer takes a function which returns a Promise. The result of the Promise's success or failure determines the response. On success, the value of the promise is passed as the body of the response with an HTTP 200. On failure, an HTTP 500 is sent to the response.

Signature

<T>(promise: () => Promise<T>) => Complete

Example

import { Router } from 'express';
import { async } from 'functional-express';

Router()
  .route('/')
  .post(
    async(
      () => somePromise(),
    ),
  );

Extractors

params

The params extractor extracts path parameter values and passes them to an inner function.

Signature

(params: Params) => AsyncNestedFunc | NestedFunc | Complete

Example

import { Router } from 'express';
import { params } from 'functional-express';

Router()
  .route('/:pathA/:pathB')
  .post(
    params(({ pathA, pathB }) => 
      // Values of pathA and pathB now available here
    ),
  );

bodyRaw

The bodyRaw extractor extracts the request body, unaltered, and passes it to an inner function.

Signature

<T>(body: T) => AsyncNestedFunc | NestedFunc | Complete

Example

import { Router } from 'express';
import { bodyRaw } from 'functional-express';

Router()
  .route('/')
  .post(
    bodyRaw<any>((body: any) => 
      // The body is now available here
    ),
  );

body

The body extractor extracts the request body and validates it against a class-validator decorated class. If the class is validated, it is passed to an inner function and can be used subsequently. If the class fails validation, an HTTP 500 is sent to the response with the validation failure output passed as the body.

Signature

<T extends object>(classType: ClassType<T>, bodyFunc: BodyFunc<T>) => AsyncNestedFunc | NestedFunc | Complete

Example

import { IsNotEmpty, IsNumber } from 'class-validator';
import { Router } from 'express';
import { body } from 'functional-express';

class SomeClass {
  
  @IsNotEmpty()
  @IsNumber()
  public someNumber: number;
  
}

Router()
  .route('/')
  .post(
    body(SomeClass, (body: SomeClass) => 
      // The validated class is now available here
    ),
  );

Questions?

Open an issue and I'll try to answer asap!

Contributions?

If you'd like to contribute, open a PR and I'll look over it asap. All contributions will be made available under the MIT license.