Run a sample App Percy build with WebdriverIO and JavaScript

Clone the sample application

Clone the sample application and install the required dependencies:

Upload the sample application

Upload the sample application to BrowserStack App Automate:

After the command runs successfully, you get a response similar to the following:

Make a note of the app url.

To know more about uploading an app to App Automate, refer to the Upload an App REST API documentation.

Create an App Percy project

Sign in to Percy and create a new app project, for example, test-project. After you’ve created the project, you’ll be shown a Percy Access Token. Use it in the next step.

Set Percy token as an environment variable

Export the token environment variable:

Generate the first build

Check out a new branch for your work in this tutorial (we’ll call this branch tutorial-example), then run tests & take screenshots:

$ git checkout -b tutorial-example
$ cd wd
$ npm install

Now run the build with following commands

npx percy app:exec -- node android.js

npx percy app:exec -- node ios.js

This will run the app’s JavaScript Appium tests, which contain calls to create Percy screenshots. The screenshots will then be uploaded to Percy for comparison. Percy will use the PERCY_TOKEN you used in Step 2 to know which organization and project to upload the screenshots to.

In general, your test would look like the below example. Whenever you have to capture a screenshot for visual testing, use percyScreenshot function.

You can view the screenshots in Percy now if you want, but there will be no visual comparisons yet. You’ll see that Percy shows you that these screenshots come from your tutorial-example branch.

Modify the sample application

Now, it’s time to introduce some visual changes to your app. Replace the search_input.send_keys in your test script as shown below.

search_input.send_keys("BrowserStack again")

search_input.send_keys("BrowserStack again")

Commit your changes

Create a commit with the changes.

Run tests again

Run the tests with screenshots again.

npx percy app:exec -- node android.js

npx percy app:exec -- node ios.js

View visual differences on dashboard

Visit your project in Percy and you’ll see a new build with visual comparisons between the two runs. Click anywhere on the Build 2 row (we are assuming here that you are using a new project to test things out). You can see the original screenshots on the left, and the new screenshots on the right.

Percy has highlighted what’s changed visually in the app! Screenshots with the largest changes are shown first You can click on the highlight to reveal the underlying screenshot.

If you scroll down, you’ll see that no other test cases were impacted by our changes to text. The unchanged screenshots are shown under an Unchanged filter and are hidden by default.