A simple Node.js Gmail client which checks/returns email message(s) straight from any Gmail-powered account (both private and company).
There are two main functionalities this library provides:

1. check_inbox(): Polls a mailbox for a given amount of time. At the end of the operation, the desired message is returned (if found).
2. get_messages(): Can be used to perform various assertions on the email objects (see example below).

P.S, I have written a story on medium, how using Cypress, we are testing our user registration process at Tastewise.

1. Install using npm:

npm install --save-dev gmail-tester

2. Save the Google Cloud Platform OAuth2 Authentication file named credentials.json inside an accessible directory (see instructions below).
3. In terminal, run the following command:

node <node_modules>/gmail-tester/init.js <path-to-credentials.json> <path-to-token.json> <target-email>

<path-to-credentials.json> Is the path to OAuth2 Authentication file.
<path-to-token.json> Is the path to OAuth2 token. If it doesn't exist, the script will create it.
The script will prompt you to go to google.com to activate a token. Go to the given link, and select the account for <target-email>. Grant permission to view your email messages and settings. At the end of the process you should see the token:

Hit the copy button and paste it to init.js script. The process should look like this:

1. Follow the instructions to Create a client ID and client secret. Make sure to select Desktop app for the application type.

2. Once done, go to https://console.cloud.google.com/apis/credentials?project=(project-name)&folder&organizationId and download the OAuth2 credentials file, as shown in the image below. Make sure to replace (project-name) with your project name.

   

   The credentials.json file should look like this:

   

3. Make sure the Gmail API is activated for your account.

If everything is done right, the last output from the script should be:

[gmail] Found!

Congratulations! gmail-tester is ready to use.

⛔️ Never share or commit credentials.json nor token.json!!! Whoever has it will have full access to your inbox!

credentials: Path to credentials JSON file or JSON Object.
token: Path to OAuth2 token file or JSON Object.
options:

• from: String. Filter on the email address of the receiver.
• to: String. Filter on the email address of the sender.
• subject: String. Filter on the subject of the email.
• include_body: boolean. Set to true to fetch decoded email bodies.
• include_attachments: boolean. Set to true to fetch the base64-encoded email attachments.
• before: Date. Filter messages received before the specified date.
• after: Date. Filter messages received after the specified date.
• label: String. The default label is 'INBOX', but can be changed to 'SPAM', 'TRASH' or a custom label. For a full list of built-in labels, see https://developers.google.com/gmail/api/guides/labels?hl=en

Returns: An array of email objects with the following fields:

[
  {
    from: "Human Friendly Name <sender@email-address>",
    receiver: "your@email-address",
    subject: "string",
    body: {
      html: "string",
      text: "string"
    }
  }
  // ...
];

Some senders will send you text/html content, the others will send you plain/text, and some will send you both. Make sure you are looking for the content in the right body field.

credentials: Path to credentials JSON file or JSON Object.
token: Path to OAuth2 token file or JSON Object.
options:

• from: String. Filter on the email address of the receiver.
• to: String. Filter on the email address of the sender.
• subject: String. Filter on the subject of the email.
• include_body: boolean. Set to true to fetch decoded email bodies.
• include_attachments: boolean. Set to true to fetch the base64-encoded email attachments.
• before: Date. Filter messages received before the specified date.
• after: Date. Filter messages received after the specified date.
• wait_time_sec: Integer. Interval between inbox checks (in seconds). Default: 30 seconds.
• max_wait_time_sec: Integer. Maximum wait time (in seconds). When reached and the email was not found, the script exits. Default: 60 seconds.
• label: String. The default label is 'INBOX', but can be changed to 'SPAM', 'TRASH' or a custom label. For a full list of built-in labels, see https://developers.google.com/gmail/api/guides/labels?hl=en

Returns: An array of email objects with the following fields:

[
  {
    from: "Human Friendly Name <sender@email-address>",
    receiver: "your@email-address",
    subject: "string",
    body: {
      html: "string",
      text: "string"
    }
  }
  // ...
];

In addition, verbose messages will be written to console.

credentials: Path to credentials JSON file or JSON Object.
token: Path to OAuth2 token file or JSON Object.

Refresh the access token. A new file will overwrite the existing one in token_path.

const path = require("path");
const gmail = require("gmail-tester");
const email = await gmail.check_inbox(
  path.resolve(__dirname, "credentials.json"), // Assuming credentials.json is in the current directory.
  path.resolve(__dirname, "gmail_token.json"), // Look for gmail_token.json in the current directory (if it doesn't exists, it will be created by the script).
  {
    subject: "Activate Your Account", // We are looking for 'Activate Your Account' in the subject of the message.
    from: "no-reply@domain.com", // We are looking for a sender header which is 'no-reply@domain.com'.
    to: "<target-email>", // Which inbox to poll. credentials.json should contain the credentials to it.
    wait_time_sec: 10, // Poll interval (in seconds).
    max_wait_time_sec: 30, // Maximum poll time (in seconds), after which we'll giveup.
    include_body: true
  }
);
if (email) {
  console.log("Email was found!");
} else {
  console.log("Email was not found!");
}

cypress.config.js:

const { defineConfig } = require("cypress");
const gmailTester = require("gmail-tester");
const path = require("path");

module.exports = defineConfig({
  e2e: {
    setupNodeEvents(on, config) {
      on("task", {
        "gmail:get-messages": async (args) => {
          const messages = await gmailTester.get_messages(
            path.resolve(__dirname, "credentials.json"),
            path.resolve(__dirname, "token.json"),
            args.options
          );
          return messages;
        },
      });
    },
  },
});

spec.cy.js:

/// <reference types="Cypress" />

describe("Email assertion:", () => {
  it("Using gmail_tester.get_messages(), look for an email with specific subject and link in email body", function () {
    // debugger; //Uncomment for debugger to work...
    cy.task("gmail:get-messages", {
      options: {
        from: "AccountSupport@ubi.com",
        subject: "Ubisoft Password Change Request",
        include_body: true,
        before: new Date(2019, 8, 24, 12, 31, 13), // Before September 24rd, 2019 12:31:13
        after: new Date(2019, 7, 23), // After August 23, 2019
      },
    }).then((emails) => {
      assert.isAtLeast(
        emails.length,
        1,
        "Expected to find at least one email, but none were found!"
      );
      const body = emails[0].body.html;
      assert.isTrue(
        body.indexOf(
          "https://account-uplay.ubi.com/en-GB/action/change-password?genomeid="
        ) >= 0,
        "Found reset link!"
      );
    });
  });
});

 

Please feel free to contribute to this project.

• Built using googleapis.