https://github.com/chrisvilches/parallel-express-middleware

Utility that assembles multiple Express middlewares into a new middleware, and executes them in parallel.
https://github.com/chrisvilches/parallel-express-middleware

async-await express expressjs middleware node nodejs npm npm-package parallel

Last synced: 5 days ago
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Utility that assembles multiple Express middlewares into a new middleware, and executes them in parallel.

• Host: GitHub
• URL: https://github.com/chrisvilches/parallel-express-middleware
• Owner: ChrisVilches
• Created: 2021-06-27T15:44:56.000Z (over 3 years ago)
• Default Branch: main
• Last Pushed: 2021-06-27T17:06:34.000Z (over 3 years ago)
• Last Synced: 2025-01-03T19:39:41.634Z (about 1 month ago)
• Topics: async-await, express, expressjs, middleware, node, nodejs, npm, npm-package, parallel
• Language: JavaScript
• Homepage: https://www.npmjs.com/package/parallel-express-middleware
• Size: 34.2 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# Parallel Express Middleware

Utility that assembles multiple Express middlewares into a new middleware, and executes them in parallel.

## Install

```bash

npm install parallel-express-middleware --save

```

## Usage

```javascript

const parallel = require('parallel-express-middleware');

const getUsers = async (req, res, next) => {

  res.locals.users = await User.all();

  next();

}

const getArticles = async (req, res, next) => {

  res.locals.articles = await Article.all();

  next();

}

router.get('/', parallel(getUsers, getArticles), (req, res) => {

  // Success

  res.render('index');

}, (err, req, res, next) => {

  // Error happened

  res.send('Error!');

});

```

## Warnings

A few things must be kept in mind when using this utility.

1. Rendering functions like `render`, or `json` will be disabled and will throw an error when attempted to be used inside middlewares created using `parallel`.

2. Any exception (runtime error) that occurs inside the middlewares will execute the `next()` using the exception raised as its argument.

3. The resulting middleware generated by `parallel` will execute `next()` with an error argument as soon as any middleware calls `next()` with an error argument.

4. Order of execution is unknown. Only middlewares that don't depend on each other should be used. Don't use middlewares that modify the same data in `res.locals`, or a middleware that needs data created by another middleware being executed in parallel.