p-tap

Tap into a promise chain without affecting its value or state

Install

$ npm install p-tap

Usage

const pTap = require('p-tap');

Promise.resolve('unicorn')
    .then(pTap(console.log)) // Logs unicorn
    .then(value => {
        // value is still unicorn
    });

const pTap = require('p-tap');

getUser()
    .then(pTap(user => recordStatsAsync(user))) // Stats are saved about user async before the chain continues
    .then(user => {
        // user is the user from getUser(), not recordStatsAsync()
    });

const pTap = require('p-tap');

Promise.resolve(() => doSomething())
    .catch(pTap.catch(console.error)) // prints any errors
    .then(handleSuccess)
    .catch(handleError);

API

pTap(tapHandler)

Use this in a

.then()

Returns a thunk that returns a

Promise

pTap.catch(tapHandler)

Use this in a

.catch()

Returns a thunk that returns a

Promise

tapHandler

Type:

Function

Any return value is ignored. Exceptions thrown in

tapHandler

If

tapHandler

Promise

Related

• p-log - Log the value/error of a promise
• p-if - Conditional promise chains
• p-catch-if - Conditional promise catch handler
• More…

License

MIT © Sindre Sorhus