Appium Tutorial: A Detailed Guide To Appium Testing

Architecture of the Appium framework

This section of the Appium testing guide sheds light on the Appium framework's architecture. The Appium Architecture consists of three components -

• Appium Client
• Appium Server
• End Device

• Appium Client: The Appium client contains scripted automation code written in popular programming languages like Java, Python, Ruby, Perl, etc. The automation scripts contain the configuration details of the device and application. These scripted and configuration details are used in running the test cases.
• Appium Server: It is an HTTP server that receives JSON-formatted command requests from the client. The Appium server uses Node.js, and commands are then executed on mobile devices. Therefore, installing the server on your machine before running the test script is recommended.
• End Device: It refers to emulators, simulators, and a physical device connected to the Appium server where tests are run.

How does Appium work?

In this section of Appium testing tutorial, we will deep dive into the working of Appium framework.

Appium is a Node.js HTTP server that uses the REST API. The client interacts with the Appium server through REST APIs, which are controlled by the Mobile JSON Wire Protocol. The REST APIs accept client connections, listen for commands, execute commands, and send back the command execution status.

• To perform Appium testing, the first step is to create a session.
• During a session, the client sends a request to the server containing session-related information in key-value pairs, also known as Desired Capabilities. The Desired Capabilities enable Appium to differentiate between platforms (iOS or Android) and fire up a session on the mobile device, Android Emulator, or iOS Simulator.
• Using the JSON object (Desired Capabilities), the POST request is sent to the server, and Appium responds to it in the form of a session id.
• Once the session is up, the client and Appium server can interact with each other.

Appium works differently on platforms like Android and iOS. In the next section of this Appium testing tutorial, we will look at how Appium works on Android and iOS.

Working of Appium on Android

Appium Client libraries convert the test commands to the REST API requests with the help of the Mobile JSON Wire Protocol. The Appium server forwards these requests to the Android device or emulator. The Android device contains the bootstrap.jar files. The bootstrap.jar file interprets these test commands. The bootstrap.jar file uses Selendroid or UI Automator to execute the requests on the Android device.

The results of the tests are then sent to the Appium server, which sends an HTTP response (containing status codes) to the Appium client.

Working of Appium on iOS

Appium Client libraries convert test commands into REST API requests using the Mobile JSON Wire Protocol. The Appium server forwards these requests to an iOS device or simulator. The iOS device contains the WebDriverAgent.app files. WebDriverAgent.app interprets these test commands. WebDriverAgent.app uses XCUITest to execute requests on iOS devices.

The results of the tests are then sent to the Appium server, which sends an HTTP response (containing status codes) to the Appium client.

Prerequisites to use Appium

Before automating your apps using Appium, make sure to install the following things on your system.

• Java (JDK)
• Android Studio
• Selenium Server JAR file
• Appium Desktop Client
• Eclipse IDE
• Apk Info - App on Google Play Store
• js (Not required in case of Appium Server installation as it comes by default)

How to install Appium

You can install Appium in two ways -

• NPM (Node Package Manager)
• Appium Desktop - a GUI application

Installing Appium through NPM: You will need Node.js and NPM to run Appium through npm install. You can use nvm, n, or brew install node to install Node.js.

You will likely encounter problems installing Node or Appium with sudo (or root). Appium supports Node.js 12+, so we recommend using the latest stable version.

To install Appium through NPM, run the following command in the terminal:

npm install -g appium

Installing Appium through Appium Desktop: You can download the latest version of Appium Desktop from the Appium Release page. If you want to know more about Appium Desktop, head over to our guide on Appium Inspector.

The next section of this Appium testing guide focuses on how to install Appium on Windows and macOS.

How to set up Appium on Windows?

Shown below are the following steps for installing Appium on your Windows machine.

• Before you begin the installation process, download the required files: Android Studio, Appium Jar files for Java, Appium Client Library, Java Appium Server
• Install Java and set the environment variables.
• Install the Android Studio and then create a new project.
• Extract the Appium Client library. Keep the extracted Appium Client library and Appium Jar files in a new folder.
• Open Project view in Android Studio, select the files you just extracted ( in Step 4) and place them in the libs folder.
• Now select all the files in the libs folder, right-click and select Add As Library.
• You should notice a build.gradle file in the app folder after adding the files as a library. Double-click that, then rebuild your project.

When the project is successfully rebuilt, it indicates that you have installed Appium on your system using Android Studio.

How to set up Appium on Mac?

Shown below are the following steps for installing Appium on your Mac machine

• Download Java and set the environment variables. Run the following command to configure the environment variables -

vim ~/.bash_profile

• This will launch the Vim Editor. To enter insert mode, press I and enter the following command.

export JAVA_HOME = $(/usr/libexec/java_home)
export PATH = $JAVA_HOME/bin=$PATH
export PATH = /usr/local/bin:PATH

• Now press the escape key and enter “:wq“ to return back to the terminal. Then enter the following command -

source ~/.bash_profile

• Now install Xcode and Homebrew on your system. To install Homebrew, run the below command into your terminal.

/usr/bin/ruby -e "$(curl -fsSL
https://raw.githubusercontent.com/Homebrew/install/master/install)"

• After that, run the following commands.

brew update
brew doctor
xcode-select --install

• Download the Appium server from its official site. Once the download is complete, click on the DMG file and follow the on-screen instructions. Next, simply drag and drop Appium into your applications folder after installing it. That wraps up the Appium setup on your Mac machine.

Limitations of Appium

Shown below is the limitation of the Appium framework.

• Currently, Appium testing with Android doesn’t support Android versions below 4.2.
• Appium desktop inspector cannot be run directly on Microsoft Windows.
• While performing Appium testing on the iOS platform, the test execution is slow.
• It doesn’t support older Android APIs.
• Setting up and configuring Appium for Android and iOS is a time-consuming process.
• It doesn’t generate detailed test reports.

Troubleshooting Steps for Common Errors in Appium testing

This section of Appium testing tutorial covers some unexpected errors that you may encounter while performing Appium testing of mobile applications. Here is a list of common Appium errors and how to fix them.

• If you're using Fastboot to run your Android emulator and it's not being detected properly by ADB, perform a cold boot. Go to Android Studio > Tools > AVD Manager > Actions > Cold Boot Now. This will mainly resolve all emulator issues.
• When the Instrument crashes on iOS ("exited with code 253"), ensure Xcode has downloaded device symbols. Once you click on Window > Devices, it should automatically start. After upgrading iOS versions, it is needed.
• We must unlock the macOS keychain to build the app and the WebDriverAgent. Therefore, it is imperative when you use SSH.
• When you install Node and npm via MacPorts, Appium may have difficulty finding the node executable. It is necessary to include the MacPorts bin folder (default path is /opt/local/bin) in PATH in /.profile, /.bash_profile, or ~/.bashrc.
• Running iOS tests and getting the error "[INST STDERR] posix spawn failure; aborting launch" means your app is not compiled correctly.

Is Appium easy to learn?

Yes! The learning curve of Appium is quite simple and easy. It employs the remote WebDriver protocol and supports various languages and frameworks. You can begin your Appium testing journey if you have good experience writing tests in languages like Java, Python, PHP, C#, and others.

Please refer to our Appium testing tutorial for more information on the essentials of Appium.

How do I get started with Appium?

Appium is an excellent framework to include in your test automation plan. However, it is critical to conduct Appium testing effectively. Setting up, running, and scaling in-house device labs is costly. This demands the use of a real device cloud platform like LambdaTest. With LambdaTest online device farm, you can get rid of your in-house device labs and allow your developers and testers to conduct Appium testing on real devices from anywhere at any time.

About LambdaTest

LambdaTest is a leading test execution and orchestration platform that is fast, reliable, scalable, and secure. It allows users to run manual and automated testing of web and mobile apps across 3000+ browsers, operating systems, and real device combinations. Using LambdaTest, businesses can ensure quicker developer feedback and hence achieve a faster go-to-market. Over 500 enterprises and 1 Million + users across 130+ countries rely on LambdaTest for their testing needs.

Getting Started with Appium testing on LambdaTest

To start Appium testing on LambdaTest, you can refer to our Appium testing support documentation for a step-by-step procedure for running your first Appium test script on a cloud Appium Grid. So you don’t have to worry about the challenges with Appium infrastructure as we will provide you with a cloud Appium Grid with zero downtime.

Want to know a fun fact? Your first 100 Appium testing minutes are on us with just a free sign-up. In addition, you can also avail benefits of manual cross browser testing, manual app testing, Visual UI testing, responsive testing, and more with a lifetime of free access to LambdaTest, the world’s fastest-growing test orchestration, and execution platform.

Ready to automate your apps using Appium? To get started, watch our Appium testing tutorial video.

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