example-percy-appium-python

Example app used by the Percy Python Appium tutorial demonstrating Percy's Python Appium integration.

Note: This tutorial works with Appium-Python-Client >= 2.10.2

Python Appium Tutorial

The tutorial assumes you're already familiar with Python and Appium and focuses on using it with Percy. You'll still be able to follow along if you're not familiar with Python, Appium, but we won't spend time introducing Python, Appium concepts.

The tutorial also assumes you have Node 14+ with npm and git installed.

Step 1

Clone the example application and install dependencies:

Minimum required @percy/cli version is 1.15.0 for this to work correctly. If you already have @percy/cli installed please update it to latest or minium required version with npm update -g @percy/cli.

$ git clone https://github.com/percy/example-percy-appium-python.git
$ cd example-percy-appium-python
$ make install

This tutorial specifically uses Browserstack App Automate to run appium test, even though you should be able to follow the tutorial if you are using any other service to run appium tests or running it locally. For app percy to work we only need to initialize AppPercy with driver object.

In case you are choosing to use Browserstack App Automate, please follow following steps:

1. You will need a BrowserStack username and access key. To obtain your access credentials, sign up for a free trial or purchase a plan.

2. Please get your username and access key from profile page.

Example Android and iOS apps are provided in resources/ folder. You can upload them using following curl command

$ curl -u "<username>:<access key>" \
  -X POST "https://api-cloud.browserstack.com/app-automate/upload" \
  -F "file=@resources/ios_resources/BStackSampleApp.ipa" # for iOS, for android use resources/android_resources/WikipediaSample.apk  
# You will get output similar to following, keep track of this app url
{"app_url":"bs://b3d22f77ac5c4064bc1892f1c470d3728a9b697f"}

You can also follow upload your app if using App Automate for latest instructions.

Step 2

Sign in to Percy and create a new App project. You can name the project "test-project" if you'd like. 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:

Unix

$ export PERCY_TOKEN="<your token here>"

Windows

$ set PERCY_TOKEN="<your token here>"

# PowerShell
$ $Env:PERCY_TOKEN="<your token here>"

Update USER_NAME, ACCESS_KEY and <APP URL> with Browserstack User name, Access key and App URL

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

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
# For Android
$ make test-android
# For iOS
$ make test-ios

This will run the app's Python 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.

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.

Step 5

Depending on if you ran Android or iOS tests, please find one of the following lines in code and update it to change content on screen

For android.py

search_input.send_keys("BrowserStack")  // Say change this to "App Percy"

For ios.py

text_input.send_keys("[email protected]" + "\n") // Say change this to "[email protected]"

Step 6

Commit the change:

$ git commit -am "Text Changed"

Step 7

Run the tests with screenshots again:

# For Android
$ make test-android
# For iOS
$ make test-ios

This will run the tests again and take new screenshots of our modified application. The new screenshots will be uploaded to Percy and compared with the previous screenshots, showing any visual diffs.

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

Step 8

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. 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 Unchanged filter and are hidden by default.

Finished! 😀

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