An API is similar to Software as a Service (SaaS) in that programmers do not have to start from scratch each time they create an application.
Instead of developing a single program that attempts to handle everything, the same application might delegate specific functions to distant software that does them more effectively.
What is REST?
RESTful (Representational State Transfer) Web Service or RESTful API is based on REST technology, REST technology is often favored over the Simple Object Access Protocol (SOAP) technology. APIs are developing to expose web services as cloud use increases. REST is an obvious option for developing APIs that enable users to connect and interact with cloud services.
Typically, “rest assured” is a synonym for “relax and don’t be concerned.” In contrast, the expression has a quite different meaning in Java programming. Because REST is an abbreviation for representational state transfer, it is first represented as REST Assured. It is an architectural pattern or style for APIs. As resource information, a RESTful web application discloses information about itself. Therefore, when a RESTful API is used, the server provides to the client a representation of the requested resource’s state.
RESTful API is a web application that utilizes HTTP requests to GET, PUT, POST, and DELETE data. It uses less bandwidth than SOAP and is thus more appropriate for internet use.
REST Assured
REST Assured is a Java package; provides programmers with a domain-specific language (DSL) for API testing. It is utilized to validate REST APIs using the Java library. The REST Assured library may be used to test response status code, content, message, and headers. It is compatible with build tools such as Maven and unit test frameworks such as JUnit and TestNG.
It features an effective matching mechanism that allows us to check the predicted outcomes.
REST Assured is commonly used to test JSON and XML-based web applications. In addition, all methods are supported, including GET, DELETE, PUT, POST, and PATCH. It is that maintainable and resilient.
Java library functions as a headless client for Rest web services. The Rest Assured library-based libraries are also capable of verifying HTTP replies from the server.
REST services are easily integrated with existing websites and are accessible as XML, allowing HTML pages to consume them without difficulty. People may test this circumstance by restarting the server and ensuring that interactions continue to function There is minimal need to modify the current architecture of the site. As a result, developers are more productive since they do not need to redo everything from scratch; they only need to add features to the current system.
As there is no set of standards to characterize the REST web services interface, service providers and consumers must comprehend the context and material being handed along. Its caching architecture could enhance speed if the information returned by the service is not regularly updated or dynamic. Restricted profile devices include smartphones, where the overhead of additional parameters is minimal (e.g., headers).
What is API Testing?
API Testing ensures delivery of promised features, safety, speed, and dependability. When testing an API, attention is paid to the application’s and data’s security. The DevOps, QA, and development communities typically employ automated API testing as part of their continuous testing processes. These tests are executed either on the API itself or as a component of larger integration tests. In order to test an API, it must first be invoked by sending requests to its endpoints and then comparing the responses to those that were specified as expected. API testing requires the rationale behind how the program operates.
Importance of API testing
Forgetting to fix issues at the server or unit levels is an expensive mistake that can push back the product’s release and necessitate rewriting huge sections of code.
If the server does not return the correct value, the corresponding element will not be shown in the UI layer. As a result, developers may eliminate 50% of the current flaws before they escalate. Testers can also send requests that aren’t feasible through the user interface, which is essential for finding vulnerabilities.
In order to speed up software deployment, many businesses are turning to microservices for their software applications. Even if an update is being made to one part of the program, the remainder will continue to operate normally. Each part of the program has its own data store and its own set of instructions for accessing that store.
Unit tests and API tests are preferable over GUI tests in Agile settings due to their low maintenance requirements and high throughput. In order to keep up with the rapid rate of change in an Agile setting, GUI tests typically require extensive revision.
Testing Types
Many test may be run to verify that the API is functioning correctly. There are both broad and narrow assessments of the program available. During Validation testing the API’s product usability, transactional behavior, and operational efficiency are evaluated. Validation testing typically entails questions like:
- Does the API’s design ensure that the product achieves its aims and addresses the problem it’s meant to address?
- Were there any egregious blunders in the code that would take the API on an unworkable course?
- Can you verify that the API is using the correct policies to get data?
A load test is conducted after a unit or codebase has been developed to see if the theoretical solution can be implemented in practice. Authorization checks for accessing resources and verifying user rights management are two key components of security testing. The API is subjected to an assault by a participant who has just rudimentary familiarity with it. This enables testers to assess the attack vector from an outside perspective. For the purposes of penetration testing, attacks might be confined to certain parts of the API or directed against the API as a whole.
Tools for API Testing
In order to test an API, developers can create their own framework from scratch or utilize one of several premade tools available online.
Testers can develop their own framework but doing so requires advanced coding abilities.
API testing tools provide straightforward interfaces that need little in the way of coding knowledge, allowing even inexperienced programmers to deploy the tests with relative ease.
There is a wide selection of API testing tools to choose from, including both commercial and free options. Among the many API testing tools available, a few stand out: 1) SoapUI; 2) REST Assured; 3) Swagger UI; 4) Postman. Because they are not constrained by the features of a single tool and its add-ons, developers have greater freedom to tailor the test while working inside an API test framework. The tests may be customized to include complex logic, and the testers can use any library they see fit for their preferred coding environment. Sadly, the tools are typically created to assess generic API flaws, therefore issues unique to the tester’s API may go unnoticed.