Module: api-delay

api-delay

Author:
Copyright:
  • 2019 Kevin Godell
Example

Example usage for adding delay using middleware and route handlers:

//create express app
const express = require('express');
const app = express();

// require delayNext, delayNextIf from api-delay
const { delayNext, delayNextIf } = require('api-delay');

// add a middleware delay to all routes
app.use(delayNext({ time: 200 }));

// add a conditional middleware delay to all routes
app.use(
  delayNextIf({
    time: 300,
    trigger: receiver => {
      // will trigger delay if returns true/truthy
      return receiver.req.method === 'POST';
    }
  })
);

// handle route post login and give slower response to non-premium user
app.post(
  '/login',
  // route handlers
  [
    // some middleware to authenticate user and set res.locals.premium value
    authMiddleware,
    // add 2 second delay to response if user does not have premium status
    delayNextIf({
      time: 2000,
      trigger: receiver => {
        return !receiver.res.locals.premium;
      }
    })
  ],
  (req, res) => {
    // send response after delay if finished
    res.send('response');
  }
);

Methods

(inner) delayNext(optionsopt) → {function}

Creates a middleware or route handler function that delays the call to next().

Parameters:
Name Type Attributes Description
options object <optional>

Configuration options

Properties
Name Type Attributes Default Description
time number <optional>
 1

Milliseconds to wait to call next().
Returns:

A function that can be used as app middleware or route handler structured as:

(req, res, next) => {
  // magic delay code
  next();
}
Type
function

(inner) delayNextIf(options) → {function}

Creates a middleware or route handler function that delays the call to next() if trigger function returns a truthy value.

Parameters:
Name Type Description
options object

Configuration options

Properties
Name Type Attributes Default Description
time number <optional>
 1

Milliseconds to wait to call next().
trigger Trigger

Trigger function is called with a single argument as an object containing request and response properties. If it returns a truthy value, it will trigger the delayed call to next().
see Trigger
Throws:
  • options.trigger must be a function
Type
TypeError
Returns:

A function that can be used as app middleware or route handler structured as:

(req, res, next) => {
  // magic delay code
  next();
}
Type
function

Type Definitions

Receiver

Object containing request and response properties.
Will be passed to Trigger function.

Type:
  • object
Properties:
Name Type Description
req object

Request
res object

Response

Trigger(receiver) → {boolean}

Function will trigger a delayed called to next() if it returns a truthy value.

Parameters:
Name Type Description
receiver Receiver

Object containing request and response properties. see Receiver
Returns:
  • Return a truthy value
Type
boolean