deno-puppeteer

API

A fork of Puppeteer running on Deno.

Puppeteer is a library which provides a high-level API to control Chrome, Chromium, or Firefox Nightly over the DevTools Protocol. Puppeteer runs headless by default, but can be configured to run full (non-headless) Chrome or Chromium.

Most things that you can do manually in the browser can be done using Puppeteer! Here are a few examples to get you started:

• Generate screenshots and PDFs of pages.
• Crawl a SPA (Single-Page Application) and generate pre-rendered content (i.e. “SSR” (Server-Side Rendering)).
• Automate form submission, UI testing, keyboard input, etc.
• Create an up-to-date, automated testing environment. Run your tests directly in the latest version of Chrome using the latest JavaScript and browser features.
• Capture a timeline trace of your site to help diagnose performance issues.
• Test Chrome Extensions.

Getting Started

Installation

To use Puppeteer, import it like so:

import puppeteer from "https://deno.land/x/[email protected]/mod.ts";

Puppeteer can use any recent version of Chromium or Firefox Nightly, but this version of Puppeteer is only validated against a specific version. To cache these versions in the Puppeteer cache, run the commands below.

PUPPETEER_PRODUCT=chrome deno run -A --unstable https://deno.land/x/[email protected]/install.ts
PUPPETEER_PRODUCT=firefox deno run -A --unstable https://deno.land/x/[email protected]/install.ts

You can find all of the supported environment variables to customize installation in the Puppeteer docs.

Usage

Puppeteer will be familiar to people using other browser testing frameworks. You create an instance of Browser, open pages, and then manipulate them with Puppeteer’s API.

Example - navigating to https://example.com and saving a screenshot as example.png:

Save file as example.js

import puppeteer from "https://deno.land/x/[email protected]/mod.ts";

const browser = await puppeteer.launch();
const page = await browser.newPage();
await page.goto("https://example.com");
await page.screenshot({ path: "example.png" });

await browser.close();

Execute script on the command line

deno run -A --unstable example.js

Puppeteer sets an initial page size to 800×600px, which defines the screenshot size. The page size can be customized with Page.setViewport().

Example - create a PDF.

Save file as hn.js

import puppeteer from "https://deno.land/x/[email protected]/mod.ts";

const browser = await puppeteer.launch();
const page = await browser.newPage();
await page.goto("https://news.ycombinator.com", {
  waitUntil: "networkidle2",
});
await page.pdf({ path: "hn.pdf", format: "A4" });

await browser.close();

Execute script on the command line

deno run -A --unstable hn.js

See Page.pdf() for more information about creating pdfs.

Example - evaluate script in the context of the page

Save file as get-dimensions.js

import puppeteer from "https://deno.land/x/[email protected]/mod.ts";

const browser = await puppeteer.launch();
const page = await browser.newPage();
await page.goto("https://example.com");

// Get the "viewport" of the page, as reported by the page.
const dimensions = await page.evaluate(() => {
  return {
    width: document.documentElement.clientWidth,
    height: document.documentElement.clientHeight,
    deviceScaleFactor: window.devicePixelRatio,
  };
});

console.log("Dimensions:", dimensions);

await browser.close();

Execute script on the command line

deno run -A --unstable get-dimensions.js

FAQ

How does deno-puppeteer compare to the Node version?

deno-puppeteer effectively runs a regular version of Puppeteer, except for some minor changes to make it compatible with Deno.

The most noticable difference is likely that instead of some methods taking / returning Node Buffer, they take / return Uint8Array. One method also returns a web native ReadableStream instead of the Node Readable.

Other than this, the documentation on https://pptr.dev generally applies.

How to run in Docker?

An example Dockerfile can be found in this repository. It will install all necessary dependencies, and shows how to run the ./examples/docker.js.

It is just meant as a jumping off point - customize it as you wish.