dAppeteer

E2E testing for dApps using Puppeteer + MetaMask

Installation

$ npm install -s @chainsafe/dappeteer
$ yarn add @chainsafe/dappeteer

Usage

import dappeteer from '@chainsafe/dappeteer';

async function main() {
  const { metaMask, browser } = await dappeteer.bootstrap();

  // create a new page and visit your dapp
  const dappPage = await browser.newPage();
  await dappPage.goto('http://my-dapp.com');

  // you can change the network if you want
  await metaMask.switchNetwork('goerli');

  // do something in your dapp that prompts MetaMask to add a Token
  const addTokenButton = await dappPage.$('#add-token');
  await addTokenButton.click();
  // instruct MetaMask to accept this request
  await metaMask.acceptAddToken();

  // do something that prompts MetaMask to confirm a transaction
  const payButton = await dappPage.$('#pay-with-eth');
  await payButton.click();

  // 🏌
  await metaMask.confirmTransaction();
}

main();

Usage with Snaps

import dappeteer from '@chainsafe/dappeteer';
import { exec } from "child_process";

async function buildSnap(): Promise<string> {
  console.log(`Building my-snap...`);
  await new Promise((resolve, reject) => {
    exec(`cd ./my-snap && npx mm-snap build`, (error, stdout) => {
      if (error) {
        reject(error);
        return;
      }
      resolve(stdout);
    });
  });

  return "./my-snap";
}

async function main() {
  // build your local snap
  const builtSnapDir = await buildSnap()

  // setup dappateer and install your snap
  const { metaMask, snapId, browser } = await dappeteer.initSnapEnv({
    snapIdOrLocation: builtSnapDir,
  });

  // you need to have a webpage open to interact with MetaMask, you can also visit a dApp page
  const dappPage = await browser.newPage();
  await dappPage.goto('http://example.org/');

  // invoke a method from your snap that prompts users with approve/reject dialog
  await metaMask.snaps.invokeSnap(dappPage, snapId, "my-method")

  // instruct MetaMask to accept this request
  await metaMask.snaps.dialog.positive();

  // get the notification emitter and the promise that will receive the notifications
  const emitter = await metaMask.snaps.getNotificationEmitter();
  const notificationPromise = emitter.waitForNotification();

  // do something that prompts your snap to emit notifications
  await metaMask.snaps.invokeSnap(dappPage, snapId, "notify");

  // Make sure the notification promise has resolved
  await notificationPromise;

  // You can now read the snap notifications and run tests against them
  const notifications = await metaMask.snaps.getAllNotifications();
}

main();

• All methods can be found on API page
• Instructions to setup dAppeteer with Jest
• Mocha example can be found inside test folder