Discover YAML Based Test Automation Framework with Maestro


The Maestro Automation Framework stands out as a robust open-source tool, offering a plethora of features beneficial to software development teams. While it boasts of many strengths, it is essential for organizations to be aware of its limitations. By understanding these limitations and adhering to best practices, teams can harness Maestro's capabilities to its fullest, ensuring efficient testing processes and the delivery of top-tier software products.

Are you a developer who's struggling with creating test scripts for mobile applications using multiple programming languages? Would you like to discover a more straightforward and easier-to-use framework for writing and maintaining test scripts? If so, you might be interested in learning about the Maestro Automation Framework. In this article, we'll explore the advantages of using the YAML based testing automation framework, Maestro.

By comparing it with traditional frameworks like Appium, describing some of its key features and benefits, I hope to provide you with a constructive argument on why Maestro can be a compelling choice for mobile app testing. So, let's take a closer look at Maestro and see if it fits your testing needs.

Maestro vs Appium

First let’s explore the benefits of using Maestro versus Appium for a simple mobile app, Twitter. In the below program, I demonstrate how to perform tap, swipe, press, and multi-touch actions. As you read through the code, imagine being a mobile app tester who needs to ensure the quality of the app with limited time and resources. With Maestro, you can easily write test scripts in a structured, human-readable format, such as the one below:

Maestro Code using YAML language

As you can see, Maestro's code is easy to understand and modify, even for non-technical team members. In comparison, Appium's code can be verbose and requires a deep understanding of the programming language. Here is the same test script written in Appium's Java code:

Appium code using Java Language

Maestro Features

Despite being new to a market that is currently saturated with automation tools, Maestro is already making waves thanks to its powerful features and user-friendly design. Below are a few examples of Maestro's features:

  • Declarative testing: Maestro scripts are written in YAML, which is a human-readable and intuitive format. This makes it easy to read, write, and maintain test scripts, even for complex scenarios.
  • Built-in support for mobile and web: Maestro provides built-in support for testing mobile and web applications. This means that you don't need to learn a separate framework for each type of application.
  • Parallel execution and distributed testing: Maestro supports parallel execution and distributed testing, which allows you to test multiple applications and devices simultaneously. This can significantly reduce the time it takes to run your tests.
  • Reporting and analytics: Maestro provides comprehensive reporting and analytics capabilities. This allows you to track the progress of your tests and identify areas where you need to improve.
  • Extensibility: Maestro is highly extensible. You can create your own plugins to add new features and functionality to the framework.

One key feature of the Maestro Automation Framework is the seamless integration of Maestro-Studio with the Maestro CLI. Maestro-Studio, which serves as the primary control center for managing and executing test automation, is built right into the Maestro CLI. This integration allows testers and developers to access Maestro-Studio directly from the command line interface, making it faster and easier to perform common testing tasks such as creating, editing, and executing test scripts. By eliminating the need for switching between multiple tools and interfaces, Maestro-Studio integrated with the Maestro CLI streamlines the entire testing process and enables teams to achieve more efficient and productive testing outcomes.

The Maestro Automation Framework is built using a modular architecture, with each module designed to perform a specific function. The framework consists of three main components: the Maestro Server, the Maestro Agent, and the Maestro CLI. The Maestro Server is the central component of the framework and is responsible for managing the execution of test scripts across multiple devices and operating systems. The server communicates with the Maestro Agents, which are installed on the devices being used for testing. The Maestro Agents are responsible for executing the test scripts and reporting the results back to the Maestro Server. The Maestro CLI is a command-line interface that provides developers with a way to interact with the Maestro Automation Framework using a set of predefined commands. This allows developers to automate the testing process and integrate it with their existing development workflows.

Other Benefits of Maestro

Maestro provides easy to create mobile automation tests, which can be especially useful in complex scenarios. Below are some examples of complex scenarios that can be tested with Maestro:

  • Testing the ability to upload a photo to a social media app, apply filters and effects, and share the photo with friends.
  • Testing the ability to book a flight on a travel booking app, including selecting the flight, entering passenger information, and paying for the flight.
  • Testing the ability to order food from a food delivery app, including selecting the restaurant, adding items to the cart, and entering delivery information.
  • Testing the ability to navigate to a specific location on a map app, including searching for the location, getting directions, and following the directions.
  • Testing the ability to play a video game, including completing levels, defeating enemies, and using special abilities.

Maestro’s foundation is built on its predecessors (i.e. Appium, Espresso, UIAutomator, and XCTest) which means that it offers a wealth of features and functionalities that have been refined and optimized over time.

  • Its focus on defining and testing Flows, which are parts of the user journey in an app, makes it easy to create comprehensive and effective test scenarios.
  • It has built-in tolerance to flakiness and delays, meaning that it is designed to handle the inherent instability of mobile applications and devices. This results in more reliable and consistent test results.
  • Its fast iteration capability allows for rapid testing cycles, with tests being interpreted and automatically rerun as changes are made.
  • It has a simple setup, with it being a single binary that works anywhere, making it easy to get started with and use on any platform.

Limitations of Maestro

As with all tools, there are several drawbacks to using Maestro as shown below:

  • Maestro doesn’t support iOS real devices.
  • It only supports simple actions, as complex logic cannot be written with YAML.
  • When a step fails, the failure is displayed, but the reason for the failure is not provided.
  • Tests are halted immediately upon encountering a failed step.
  • Constants cannot be defined within the framework.
  • No screenshots are captured if a test fails.
  • Substrings within a string cannot be matched unless Regex is used. However, this Regex functionality is limited to Android and is not supported on iOS.


The Maestro Automation Framework stands out as a robust tool, offering a plethora of features beneficial to software development teams. While it boasts of many strengths, it is essential for organizations to be aware of its limitations, some of which include lack of support for iOS real devices and constraints in handling complex logic with YAML. By understanding these limitations and adhering to best practices, teams can harness Maestro's capabilities to its fullest, ensuring efficient testing processes and the delivery of top-tier software products.

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