Percy Developer Hub

Welcome to the Percy Developer Hub. You'll find comprehensive guides and documentation to help you start working with Percy as quickly as possible, as well as support if you get stuck. Let's jump right in!

Ember tutorial


Covered in this doc

Cloning an example application with Percy already integrated
Making some changes and seeing the snapshots and visual diffs in Percy

The tutorial assumes you have ember, git, and Google Chrome installed.

Step 1: Clone the example app:

$ git clone
$ cd example-ember

Step 2: Sign in to Percy, create a new organization, and create a new project. You can name both the organization and project 'todo'.

After you've created the project, you'll be shown a token environment variable.

Step 3: In the shell window you're working in, export the token environment variable:

# Windows
$ set PERCY_TOKEN=<your token here>

# Unix 
$ export PERCY_TOKEN=<your token here>

Note: Usually this would only be set up in your CI environment, but to keep things simple we'll configure it in your shell so that Percy is enabled in your local environment.

Step 4: Install the example app's dependencies:

$ npm install

Step 5: Run the tests:

$ npm test:percy

This will run the test suite and send snapshots to Percy. You can view the snapshots in Percy now if you want, but there will be no visual comparisons yet.

Step 6: Use your text editor to edit app/styles/app.css and change the #new-todo background-color from #ffffff to #f5f5f5.

Step 7: Also edit app/templates/application.hbs and edit the footer to add a new paragraph on line 29: <p>Now tested with Percy</p>

Step 8: Commit the change:

$ git add . && git commit -m "Changed background color and updated footer."

Step 9: Run the tests again:

$ npm test:percy

This will take snapshots of our modified application, render new screenshots to compare against previously rendered screenshots, and detect visual changes between the two.

At the end of the run output, you will see logs from Percy confirming that the screenshots were successfully rendered and giving you a direct URL to check out the visual changes.

Step 10: Visit your project in Percy and you'll see a new build with the visual comparisons between the two runs. Click anywhere on the Build 2 row. Individual screenshots are grouped into snapshots for each page. By default, Percy renders screenshots at 375px and 1280, and across both Firefox and Chrome. You can see the baseline snapshots on the left, and the new snapshots on the right.

Percy has highlighted what's changed visually in the app! Snapshots with the largest changes are shown first You can click on the right panel to reveal the underlying screenshot.

If you scroll down, you'll see that no other snapshots were affected by our changes to the 'Clear completed' button. The unchanged snapshots appear grouped together at the bottom of the list.

Finished! ūüėÄ

From here, you can try making your own changes to the app if you like. If you do re-run the tests, and then you'll see your changes reflected in Percy.

Updated 9 months ago

What's next

Check out the example app on GitHub and learn how to add Percy to your own Ember app!


Ember tutorial

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