Frequently Asked Questions

Find answers to common Maestro questions. This FAQ covers troubleshooting tips, installation issues, and guidance for running reliable mobile and web tests.

How can I use the same flow when my apps have different app IDs?

If you want to run the same flow for apps with different app IDs, you can use an external parameter for appId. Pass the parameter APP_ID to Maestro:

maestro test -e APP_ID=your.app.id file.yaml

And then refer to it in your flow using ${APP_ID}:

appId: ${APP_ID}
---
- launchApp

How do I assert on a string that contains a dollar sign?

Values with dollar signs can be interpreted as variables. To avoid this, escape the dollar characters.

- assertVisible: \$150 in Cash

How do I compare two values?

To assert on values that exist on different screens, store them in variables.

# Perform steps to navigate to first value, then:
- copyTextFrom: 
    id: 'listView1'
- evalScript: ${output.firstPrice = maestro.copiedText}

# Perform steps to navigate to the second value, then:
- copyTextFrom: 
    id: 'detailView'
- evalScript: ${output.secondPrice = maestro.copiedText}

# Compare the values:
- runFlow:
    when:
      true: ${output.firstPrice === output.secondPrice}
    commands:
      - evalScript: ${console.log('Prices match! Both are ' + output.secondPrice)}

How do I generate a random number?

Whilst there are commands for random strings and names, there's no function for generating random numbers. Users can use JavaScript to generate a number in the range they need.

randomNumber.js :

// Generate an 8 digit random number
output.randomNumber = Math.floor(Math.random() * 90000000) + 10000000;

flow.yaml:

- runScript: ../scripts/randomNumber.js
- evalScript: ${EMAIL = "maestro+" + output.randomNumber + "@domain.com"}

Why does YES get translated to true, and NO to false?

If you attempt to do this to tap on a YES button:

appId: com.example
---
- launchApp
- tapOn: YES

Then you'll get an error like this one:

 ║  > Flow: flow                         
 ║                                       
 ║    ❌   Tap on "true"                 
 ║                                       
                                         
Element not found: Text matching regex: true

Element with Text matching regex: true not found. Check the UI hierarchy in debug artifacts to verify if the element exists.

That's a side effect of YAML. The specification allows a boolean to be defined as any of true/false, yes/no, on/off or Y/N. Or different casings of those.

To actually specify the words Yes or No, you have two options. One is to use quotes to force it to be interpreted as text. The other is to specify it as a regular expression, so that it's not just a Yes or a No.

appId: com.example
---
- launchApp
- tapOn: "YES"
- tapOn: ^No    # Text that begins with "No"

Why are my tests slower in Maestro's cloud environment?

The cloud environment optimises for reliability and repeatability, on the belief that slower correct results beat faster inconsistent results, every time. Each device, between one test and the next, is wiped and recreated, so that there's no chance of any test ever affecting any other. Compared with running locally, this adds 2-4 minutes between tests. To improve total time to finish a run, consider adding additional parallel runners. Another option is restructuring your tests for fewer longer tests, but be sure you're not making the same mistake, and sacrificing reliability or information in favour of speed.