In this blog post, we'll discuss the most effective tools to do mobile app API testing, along with a step-by-step guide to perform it yourself.

If you're familiar with mobile app development, you would know how integral APIs have become for businesses, making sharing services easy and accessible on all devices and platforms.

As much as API is fundamental to mobile applications, it is essential to ensure API quality and smooth functioning through effective testing throughout the evolutionary phase.

While checking on the API functionalities, API testing also validates secure and highly reliable performance, letting developers keep an eye on potential vulnerabilities and performance issues in the initial stages of testing and deployment.

What is Mobile App API Testing?

API testing generally follows the below steps:

1. Set up the Testing Environment

2. Write Test Cases

3. Run the Tests

4. Analyze the Results

5. Repeat as Necessary

Mobile app API testing is typically performed in a separate testing environment that simulates the production environment. This allows developers to focus on testing the API without having to worry about the application's other dependencies.

Once the testing environment is set up, developers will write test cases that exercise the API and assess its functionality. These test cases can be run manually or automatically.

After the tests are run, the results are analyzed to identify any issues. If necessary, the process is repeated until all issues have been resolved.

Types of Mobile App API Testing

Mobile App API testing can be performed manually or automated. Manual testing can be useful for exploratory testing or when you're first getting started with a new API. But automated tests are faster and more reliable, and help to identify issues more quickly. Automated tests are conducted by special testing tools.

There are various types of Mobile App API testing, each with its own purpose, the most common categories being functional, load, security, and compliance tests.

• Mobile App API Functional Testing

Mobile API Functional tests focus on the API's functionality and ensure that it responds as per the expectations and within the set protocols. One can use data-driven testing for vast amounts of input data and respective output, or leverage keywords for test harnesses at a higher level. This test examines specific methods inside the codebase.

• Mobile App API Load Testing (or performance testing)

Mobile app API Load testing ensures that an API can handle a high number of requests without experiencing any degradation in performance. This type of test is important for ensuring that the Mobile API will be able to handle peak traffic periods without any issues. It is conducted using Mobile API Load Testing tools.

• Mobile App API Security Testing

Mobile App Security testing focuses on assessing the security of an API and its data. This includes tests for vulnerabilities such as SQL injection and cross-site scripting (XSS). These tests can be used to ensure that the Mobile App API is properly configured and that sensitive data is protected.

• Mobile App API Compliance Testing

Mobile App Compliance testing assesses whether an API adheres to certain standards or regulations. This type of test is important for ensuring that the Mobile App API meets industry-specific requirements.

• Mobile App API Fuzz Testing

Mobile App Fuzz testing is a type of security test that involves providing invalid or unexpected input to an API in order to assess its resilience. This type of test is important for identifying potential security vulnerabilities in Mobile App APIs.

Ways to perform Mobile App API Testing

In case of testing mobile app, both the frontend and backend should work in collaboration to provide a seamless user experience.

Like any other backend testing, mobile API testing can also be performed using a number of ways.

• Manual testing is one primary method to test APIs, which is rapidly getting taken over by the automated testing as the development teams focusses more on agility.

• There are numerous tools available in the market to perform automated testing, thereby complimenting the already fast-moving nature of automation.

Top Tools to Perform Mobile App API Testing

Since the API-driven market is expanding exponentially, new API automation tools are coming every now and then. Let’s take a quick look at some of the most talked about mobile API testing tools based on the features, usage, experience and the performance provided by them.

1️⃣ HyperTest

HyperTest is the go-to choice for thousands of agile teams, including major players like Groww, Nykaa, and PayU. It acts as the last line of defense, preventing regressions caused by code changes.

It leverages your mobile app API traffic for auto-generating integration tests, making testing processes at every new commit more feasible.

Benefits of HyperTest for Mobile App API Testing

• Generates test-cases based on real network requests: HyperTest monitors all the network requests coming to your mobile app and uses them to auto-generate test cases around them, covering every user-flow to get tested.

• Provides E2E scenario coverage: Since the test cases are essentially the path taken by a user while browsing your app, HyperTest will cover it in an end-to-end manner. Providing maximum coverage in testing all the user flows, and not missing out on any.

• No-code solution to generate integration tests: HyperTest has developed a unique approach that can help developers automatically generate integration tests that test code with all its external components for every commit, without keeping any of the dependent services up and running.

• Integration with CI/CD Pipeline: Agile teams demand speed, and CI/CD integrations are a keen factor for their success. HyperTest seamlessly integrates with any CI pipeline, catching every logical error and helping devs sign-off releases in an accelerated manner.

Website: https://www.hypertest.co/

2️⃣ Postman

Postman is a well-known tool when it comes to API testing. It's been here for a long time now, offering robust API testing solutions that big names like WhatsApp, Axis Bank are already leveraging.

Benefits of Postman for Mobile App API Testing

• Diverse Protocol and Format Support: Postman accommodates multiple protocols, formats, and authentication methods, facilitating the testing of a wide range of APIs.

• Organized Request Collections: It offers creating collections of requests and neatly organizing them into folders, variables, and environments. This enables easy reuse and sharing among team and clients.

• Automation Capabilities: Postman allows you to automate tests using scripts, assertions, and runners. This automation ensures the thorough validation of API functionality and performance across various scenarios and conditions.

• Integration with Key Tools: It seamlessly integrates with popular tools such as GitHub, Jenkins, Swagger, and Firebase, streamlining your workflow and promoting collaboration.

Challenges in Mobile App API Testing with Postman

• Proxy and Emulator Setup: Installation and configuration of a proxy or emulator is necessary to capture and transmit mobile device requests effectively.

• Limited Mocking Abilities: Postman lacks built-in support for mocking or stubbing API responses, necessitating the use of third-party tools or services to simulate various data or errors.

• Advanced Feature Gaps: Postman doesn’t support advanced features or protocols like GraphQL, WebSocket, or MQTT, potentially requiring additional tools or libraries for testing these technologies.

• Resource Management: Excessive requests, collections, or environments can cause Postman to slow down and become unstable. Effective resource optimization and management are crucial to maintain performance.

Website: https://www.postman.com/

3️⃣ Apigee

Apigee, by Google, is a versatile cross-cloud API testing software powered by JavaScript. It empowers developers and testers to access its rich feature set through various editors, simplifying the process of ensuring your mobile app's API functions flawlessly.

It works best when dealing with APIs handling substantial data loads, making it the ideal choice for mobile app testing, especially in complex digital businesses.

Benefits of Apigee for Mobile App API Testing

• High Data Volume Testing: It excels at stress testing mobile app APIs with large datasets, helping identify data handling bottlenecks and ensuring optimal performance under heavy loads.

• Security Testing: Beyond functional testing, Apigee includes advanced security testing features to identify vulnerabilities and ensure mobile app APIs are robust against potential threats.

• API Traffic Simulation: With Apigee, testers can simulate various API traffic scenarios, mimicking user behavior and network conditions to assess how the mobile app API performs under different circumstances.

• Collaborative Testing: It supports collaborative testing efforts, allowing multiple team members to work on API testing projects simultaneously, enhancing efficiency.

Challenges in Mobile App API Testing with Apigee

• Integration with Third-party Services: Testing APIs that integrate with external services or third-party APIs through Apigee involve intricate setup and coordination with external providers.

• Scalability Testing: Ensuring that APIs can scale and handle increased traffic under different load scenarios is challenging, as it demands the creation of realistic load tests and monitoring systems.

• Difficult error-handling as APIs workflow gets complex: Thoroughly testing the error-handling capabilities of APIs within Apigee, including custom error messages and logging, can be technically demanding, especially in complex API workflows.

Website: https://cloud.google.com/apigee/

A Step-by-step flow to perform Mobile App API Testing

Testing with automated tools is the most common way for Mobile App API testing today. Among the automated tools, a name you can rely on for impeccable results is HyperTest. Let’s understand the stepwise procedure to perform mobile app API testing with HyperTest:

Here’s an easy 5 step guide to build a robust API test automation suite:

1️⃣ Pick any service and install HyperTest SDK

2️⃣ Deploy your service normally either locally or any other environment. HyperTest will record all the incoming and outgoing traffic of that service in that environment.

3️⃣ Go to HyperTest dashboard of all incoming and outgoing calls of this service put together as end-to-end tests

4️⃣ Install HyperTest CLI. Run these tests on a new build of your service. It will catch regressions across your service response and outgoing calls.

5️⃣ You can make HyperTest tests part of your CI pipeline using pre-push commit hooks and sign-off every release using these autonomous test suites.

To get the complete detailed step-by-step guide on this, here's the resource to help you:

Conclusion

A significant advantage of Mobile App API testing is that it allows various teams like developers, quality assurance etc, to launch the test on core functionality of an app even before the user interface is available. This helps in identifying the flaws early on in the development process and rectifying them in a true shift-left manner. Such flaws when unidentified can cost one’s time, money and efforts, resulting in rewriting a huge chunk of code and affecting timely release of the product.

With HyperTest, you ward off any risks or anxieties concerning security failing while developing mobile applications. To access all the benefits of automated API testing, utilize HyperTest - the first ever platform design of its kind - to test your mobile app APIs and Microservices.