@gregjlee/gmail-getter

gmail-getter

About package

A simple Node.js client that gets messages from Gmail API via http requests & OAuth.

Contributions are very welcome!

Installation

npm install gmail-getter

Requirements

To log into Gmail API you need to obtain credentials: Client ID, Client Secret, Refresh token. These credentails will let you get an Access token, which is required in further requests (like getting list of emails or a single email and etc.).

Steps to go:

1. Create a project in Google Cloud Console.
2. Create OAuth credentials in API & Services section (preferably, select Desktop app there if you need it for automated tests) and then download it.
3. Enable Gmail API.
4. Obtain a Refresh token.

To get a Refresh token - simply execute a command in a project root:

npx gmail-getter get-refresh-token

(or anywhere else if you've got the package installed globally)

get-refresh-token

You must put credentials.json file (p.2) in a place where you execute the command.

⚠️ credentials file name is case-sensitive ⚠️

Usage

Import

Import whatever you need from the package:

// ES6+
import {getToken, checkInbox} from 'gmail-getter'

// CommonJS
const {getToken, checkInbox} = require('gmail-getter')

or the whole package:

// ES6+
import gmail from 'gmail-getter'

// CommonJS
const gmail = require('gmail-getter')

Get Access token

You need to get an Access token before you execute other requests:

import {getToken} = 'gmail-getter'

const accessToken = await getToken(
  clientId: string,
  clientSecret: string, 
  refreshToken: string
)

It'd probably be a good idea to get it on the earlier stages of a test run (global setup?) and store it as an environment variable.

Check inbox

Use a polling function that returns an email:

const email = await checkInbox({
  token: string, 
  timeout: number, 
  step: number, 
  all: boolean, 
  query: string
})

• token is an access token
• timeout sets a maximum execution time for the function
• step sets a timeout between retries to fetch an email
• all says whether to find a single email or all mathing the query criteria
• query lets you filter out emails you want to find, you can find more about queries there

Parse HTML from the email

If your email contains html content you can parse it and even render it in the browser with a browser automation tool (like Playwright):

const html = parseHtml(email)

• email is an email that you fetch with checkInbox function

If you're maintaining an automated test - this might be the best option, as you can verify contents of the email and click any links inside of it.

Find data in the email

If your email contains html content with a link (like confirmation one) or confirmation code - you can parse it like this:

const link = findElementByRegexp(email: Email, regexp: RegExp)

• email is an email that you fetch with checkInbox function
• regexp is a regular expression that would recognize a link from the html document

Whole flow example

And that's how you can get an email you need. It'd probably be good to wrap the logic into a method and then call it from wherever you need (tests?).

import {getToken, checkInbox, findElementByRegexp} from 'gmail-getter'

const accessToken = await getToken(
  process.env.CLIENT_ID, 
  process.env.CLIENT_SECRET, 
  process.env.REFRESH_TOKEN
)

const email = await checkInbox({
  token: accessToken,
  query: 'from:squier7 subject:Test!'
})

const regexp = /(https:\/\/)(\S*)(gmail-getter)([\w\/\?\=\-]*)/im
const link = findElementByRegexp(email, regexp)