In a nutshell: APIs (Application Programming Interfaces) are all around us. This guide covers: What is API testing?, Types of API testing, Why is API testing important?, Key benefits of API testing.
APIs (Application Programming Interfaces) are all around us. Every time you use a ride-sharing app, make a mobile payment, or adjust the thermostat from your phone, you're using an API.
Essentially, these middleware programs enable different applications to communicate with one another, allowing software developers to make their tools accessible to various users from external sources.
As online cloud platforms become an increasingly integral part of consumers' daily lives, ensuring that APIs function properly through automated API testing is a crucial step in the development process.
In this article, we'll discuss API testing, why it's important, and how to perform it.
What is API Testing?
API testing is a type of software testing used by DevOps and QA teams that analyzes an application programming interface (API) to verify that it meets expected functionality, security, performance, and reliability standards. Tests are performed either directly on the API or as part of integration testing.
API testing focuses on analyzing business logic as well as the security of the application and data responses.
Generally, API testing is performed by sending requests to one or more API endpoints and comparing the response with the expected results.
Types of API Tests
Various types of tests can be performed to ensure that an API is functioning properly:
Validation Test
Analyzes API projects based on three distinct sets of criteria:
- The Usability of the API as a Product
- His transactional behavior
- Its operational effectiveness
Functional Test
Functional tests analyze specific functions within the codebase to ensure that the API operates within the expected parameters and can handle errors when results fall outside the specified parameters.
Load Testing
Used to determine how many calls an API can handle. This test is often performed after a specific unit or codebase has been completed to determine whether the theoretical solution can also function as a practical solution when operating under a given load.
Reliability Test
Ensures that the API can produce consistent results and that the connection between platforms is reliable.
Security Test
Validates the encryption methods used by the API as well as the access control design.
Security testing includes validating authorization controls for access to resources and managing user permissions.
Penetration Test
Relies on security testing. In this test, the API is attacked by someone with limited knowledge of the API. This allows testers to analyze the attack vector from an outsider’s perspective.
The attacks used in penetration tests can be limited to specific parts of the API or target the API in its entirety.
Fuzzing Testing
Forcibly injects huge amounts of random data into the system, causing it to exhibit malicious behavior, such as a forced crash or an overflow.
Why is API testing important?
API tests ensure that connections between platforms are reliable, secure, and scalable.
Robust API connections are strongly correlated with a seamless user experience, ranking alongside regression testing and end-to-end UX testing as one of the most effective tools available to testers for improving customer satisfaction.
The APIs most likely to impact the customer experience—known as public APIs—are also the fastest-growing category of APIs. These widely available APIs are an essential tool for digital transformation.
Given how widespread the use of public APIs has become, it is highly likely that any organization operating within the multibillion-dollar API economy relies on public APIs as part of its customer experience.
Key Benefits of API Testing
Detect problems before they affect users
When automated API tests are integrated into development pipelines as part of continuous testing strategies, quality teams are able to quickly detect issues before they affect customers.
With the right test automation platform, API testing enhances end-to-end testing by reflecting the full user experience.
Quality engineers can create comprehensive, customized user interface and end-to-end tests that reflect the actual customer journey.
Data points provide useful insights into the status of the application or website, enabling quality teams to monitor long-term performance trends that signal problems well before customers notice them.
The more testers are able to perform critical API tests, the better the customer experience.
Reducing the Cost of Testing
API monitoring in production allows developers to access the application without a user interface, which helps testers identify errors earlier in the development cycle rather than waiting for them to become more serious issues.
This can save money, since errors can be resolved more effectively when they are detected early.
API test automation also requires less code than automated GUI testing, which results in faster testing and lower overall costs.
Check all system components
API testing is important to ensure that your API functions as expected when faced with a wide variety of expected and unexpected requests. This process is designed to test not only the API's functionality, but also its reliability, performance, and security.
Broader test coverage makes it easier to identify any bugs at the unit, database, and server levels.
Protects the app
API testing uses extreme conditions and inputs when analyzing applications. This eliminates vulnerabilities and protects the application from malicious code.
API Testing | How to Do It?
1. Determine the API testing requirements
First, identify the API’s target user, its features and functions, and the application’s workflow, as well as the aspects, priorities, and issues you are testing.
You need to understand:
- Who will use the API?
- What features do they need?
- What data do they interact with?
Focus on addressing the main use cases
Since the main goal is to quickly incorporate testing into the delivery process, you should focus on creating value as soon as possible by ensuring that the most important aspects of the API are tested.
For example:
- Verify that access to resources is only possible through authentication and roles.
- Verify that the API remains stable even when encountering unusual or exceptional values.
- Make sure that when you return to the workflow, the API responses remain clear.
Set the input parameters
These parameters provide the API with the information it needs to perform its function. It is important to plan for all possible combinations of inputs.
2. Select an automated API testing tool that your entire team can understand
An API testing tool can help automate the API testing process and remains a valuable asset for your entire team.
Your team will find value in your tests if they help them deliver results quickly and with greater confidence, which means the following points are essential:
- Test alignment with use cases and requirements
- Stable and fast execution of test suites
- Simple Integration and Reporting
You’re constantly interacting with your team to solicit feedback, which is another reason why your API testing solution should be codeless.
However, simply automating your API tests with a no-code tool is not enough to ensure quality, which is the key factor in the successful adoption of the API.
Instead, QA engineers need to adopt a unified testing solution that makes API testing accessible to everyone in the development pipeline and enables testers to integrate API tests into user interface and end-to-end testing.
3. Run your API tests!
Now that you know what to test and have a no-code automated tool to run your tests, you can define your test cases and run your tests.
From there, you can compare the expected results with the actual results. Your test should analyze responses that include:
- Response time
- Data Quality
- Confirmation of Authorization
- HTTP Status Codes and Error Codes
Testers must monitor for failures or unexpected inputs. Response time must fall within a defined range that the teams deem acceptable, and the API must be secured against potential attacks.
Tests must also be designed to ensure that:
- Users cannot cause the application to behave unexpectedly
- The API can handle the expected user load
- The API works on multiple browsers and devices
Mr Suricate Integrate your code-free automated API tests into web flows
Mr Suricate code-free automated testing tool allows Mr Suricate to integrate your API tests into your web flows so you can monitor production environments, check API request speeds, and verify response compliance.
FAQ
What is API Testing?
API testing is a type of software testing used by DevOps and QA teams that analyzes an application programming interface (API) to verify that it meets expected functionality, security, performance, and reliability standards. Testing is performed either directly on the API or as part of integration testing.
Why is API testing important?
API testing ensures that connections between platforms are reliable, secure, and scalable. Robust API connections are strongly correlated with a seamless user experience, ranking alongside regression testing and end-to-end UX testing as one of the most effective tools testers have to improve customer satisfaction.
Further Reading
To see the solution in action, check out our automated API tests.
