Ghost Inspector
https://ghostinspector.com
Presented by:
Headless Browsers & Testing at Scale
Who am I? 👋
- Justin Klemm
- Founder of Ghost Inspector
- 4+ year old browser testing service
- Headless, Parallel, 250k tests / day
- Active in technical support... 😬
- Headless Browsers
- Testing at Scale (in Parallel)
- Ghost Inspector Demo
Headless Browsers & Testing at Scale
"Traditional" Browser Testing
Chrome "Traditional" Example
Enter "Headless" Browsers
- Browser that can run without display requirement (i.e. in a CLI)
- PhantomJS (Webkit engine)
Modern Headless Browsers
- Chrome & Firefox
- More in the future? Maybe.
Chrome Headless Example
chrome --headless --disable-gpu https://www.google.com
Headless Advantages
- Lightweight; More performant
- No display (desktop or xvfb) requirement
- Run from CLI; Run in containers
- Easier CI integration
- Cheaper
Headless Disadvantages
- Not all browsers support it (yet?)
- Initial rendering quirks (mostly resolved)
- Occasional edge-case stuff (ex: unsigned SSL certificates)
- Not ideal for manual inspection
Automation APIs & Tools
All the same APIs still work.
- WebDriver/Selenium
- Puppeteer (Chrome)
- SlimerJS (Firefox)
- Others: Ghost Inspector (code-less, managed), *lots* of other packages and services
Choosing Automation Tools
There are always trade-offs...
- WebDriver/Selenium
- Puppeteer (Chrome)
- SlimerJS (Firefox)
- Other stuff: Cypress, Ghost Inspector (code-less, managed), *lots* of others
Understand your requirements.
Testing at Scale (in Parallel)
- Previously heavy / expensive
- Now light / cheap; Docker, Lambda, Fargate, etc.
- Run 50+ tests concurrently, instead of 1
- Massive speed / efficiency gains
- Requires a shift in test design
Parallel Test Design
Parallel Testing - Best Practices
- Simple, independent tests are ideal
- Avoid state conflicts and race conditions
- Consider setting up and/or throwing away data
- Dependencies are sometimes required; Separate sequential tests from parallel tests
Why is parallel testing worth it?
- Scale
- Speed
- Independent debugging
- Less brittle
But, don't forget about this...
Demo w/Ghost Inspector
Recap
- Headless options available in Chrome and Firefox; Easy to use + lightweight
- Automation APIs + tools have trade-offs
- Huge efficiency gains when running tests in parallel
- Design shift when testing in parallel: How do you deal with state?
- Browser tests have significant maintenance costs; Test smart
Questions?
Ghost Inspector
https://ghostinspector.com
Presented by:
Justin Klemm
@justinklemm
Headless Browsers & Testing at Scale
By Justin Klemm
Headless Browsers & Testing at Scale
Chrome and Firefox now fully support a “headless” mode to help facilitate and speed up end-to-end testing, with other browsers potentially following suit. But what are headless browsers, exactly? What are the benefits? And how can they help to scale our testing efforts? This talk will explain what headless browsers are and why they’re useful. It will also discuss some of the challenges that are faced when headless browsers are used to ramp up the scale of our testing -- particular when designing end-to-end tests that will run in parallel. There will be a brief demo of the Ghost Inspector product at the end, along with a Q&A session.
