Express Utilities

Various helpful middleware that I keep rewriting for every single project

Installation

npm install express-utilities

Usage

Requiring Parameters on Requests

'use strict';
 
const { requireParams } = require('express-utils');
const parser = require('body-parser');
const app = require('express')();
 
app.use(parser.json());
 
app.post('/data', requireParams({
    body: [
        'username',
        'email'
    ]
}), (req, res) => {
    // req.body.username and req.body.email are definitely here if
    // the request made it this far
});
 
app.listen(8080);

Error Handling

Given that my target was initially Ember, errors will currently be returned as follows:

{
  "errors": [
  	{ "message": "invalid type for parameter age: asdf" },
  	{ "message": "missing parameter: body.username" }
  ]
}

Handling Types

Sometimes you need to specify a type so that you don't have to do a bunch of work in each endpoint to coerce a value and you can do that using this same method.

Given the endpoint:

app.post('/data', requireParams({
    query: [
        {
            name: 'active',
            type: 'boolean'
        }
    ],
    body: [
        'username',
        {
            name: 'email',
            type: 'string'
        },
        {
            name: 'age',
            type: 'number'
        }
    ]
}), (req, res) => {
 
});

And the request:

POST /data?active=true
 
{
  "username": "test-user",
  "email": "[e-mail]",
  "age": "19"
}
 

req.query.active would be true (rather than 'true'), age would be 19 (rather than '19') so long as the provided values are actually able to be converted i.e. not NaN or something other than 1/0/true/false in the case of a boolean.