Caching plays a crucial role in sending back a faster response to the user. If you’re making the same request several times then you don’t need to get the data from the server multiple times. You can easily cache the data and quickly get the response from the cache memory. Consider the example of an application where you have implemented some authentication features. The session data will be bloated easily if it will start occupying the resources on the server.

Developers often have different ideas about unit testing; the individual expectation of what a unit test should be varies. Most of the time, the differences aren’t in the framework used in testing. Instead, the differences lie in what’s considered to be a unit of code. When we buy a new pair of shoes, we test them out—we try them on to see if they fit. Because it’s through testing that we infer the quality of products. A quality REST app is an indication of rigorous testing done right.

  • You can get a generated code that can be used in your system integration.
  • The main difference is the client-side tests only test the behavior that we are interested in for our use cases, whilst the server-side will test all use cases.
  • This will let us create a REST API using minimal APIs, which is a quick and efficient approach to setting up a very basic API.
  • You can also check metrics like errors, latency, and quota usage for each API call you made in your personal dashboard.
  • Enhancements to the program, which can generate additional parameters for API calls, must take into account the configuration of the schema.

The second method AssertCommonResponsePartschecks the status code is what is expected and also checks the ElapsedMilliseconds on a provided stopwatch which helps with our performance assertions. You can perform tests from code, using different libraries that allow you to send an HTTP request in an appropriate way. This way is inconvenient because it is hard to maintain and reuse it. A more appropriate method is to use something like Postman or a similar application. Postman saves your queries and gives you the ability to create collections from them . As you probably know, older systems used to have monolithic user interface integrations on the server-side.

Testing an API

REST API is an approach to provide an interface for the data and services offered by a website. The REST API is a simple and lightweight protocol that uses HTTP requests to transfer data. REST API is the most popular choice for mobile and web applications, as it’s easy to build and implement. You should check RapidAPI service, which solves almost all the problems we’ve listed in this post. You’ll be able to choose from a variety of APIs, ensuring you will use the most suitable one for your needs. You will also gain data pertaining to latency, success rate, resources, and description in one click.

Why should you test REST API

In a REST API, all data are treated as resources, each one represented by a unique uniform resource identifier . For example, the Twitter API makes each tweet an available resource that can be retrieved by clients. Clients can also use Twitter’s API to post tweets and perform other actions on the site. If you know that the API is supposed to perform a particular action , the tests should check the results of that action. API testing is typically black-box testing, but to the degree that you have access to the results of the API’s actions, they should be checked.

What is the difference between REST and SOAP?

Note that API testing and unit testing are not the same thing, although they are similar. To put it bluntly, developers know their software too well, so they’re likely to miss something which may be blindingly obvious to a tester who is not acquainted with the software’s internal workings. The job of the API tester is to test the software knowing only what a user is likely to know.

If we automate these, we know that any changes in them, as well as any failures in our automation, should be investigated further. Another thing to consider is items that you’d like to be aware of if they change. Applications built with REST are generally faster than those built with other types of APIs.

It certifies the product of its handling capabilities, security features, and compatibility across platforms. Now that we’ve learned what API testing is and how important is it, let us look into how it is done. Basically, API testing is planned after builds are ready and it is crucial you understand the functions of the API that you intend to test.

Performance –Depending on our business case, performance is a key focus. The quotas themselves will vary from business to business and even endpoint to endpoint. For example, it would be desirable for ‘hot paths’ to be executed a lot quicker than less used endpoints.

Google Maps API: How to Get Started

These were easier to implement but harder to extend and scale. The reason why these APIs came in is that they allowed you to write a single responsible service that could be reused by other systems. For example, you could write a server service that could connect to both mobile and web interfaces. Typical API documentation includes all of the API’s details, such as the request format, response, error codes, resource, mandatory parameters, optional parameters, headers, and so on. Various open-source tools, such as Swagger, can be used to maintain the documentation. Unless the response includes the necessary Cache-Control or Expires header fields, this method’s responses are not cacheable.

Why should you test REST API

HTTP is a protocol used to transfer data on a TCP/IP connection between a client and a server. If you want to create data, you have to request a POST method and the server will throw a response whether it is successful or not. Functions like Performance, Security, Reliability, etc are properly tested. With the help of HATEOAS links, the client can check the link by parsing this JSON and easily make the request.

How to test an API Manually

This server makes use of HATEOAS and returns the links for corresponding actions. This makes it very easy to explore the API and also makes it flexible by allowing the server to change the endpoints. Since the current trend in scalability is horizontal scaling , storing server-side sessions can also make it hard to scale your application because it creates some difficult problems. Before REST gained popularity, SOAP was the de-facto way of accessing resources and communicating over the web. The term “testing” can be ambiguous and often means different things to different people.

Why should you test REST API

You will encounter a lot of unfamiliar concepts in API when you will start working on it. If you’re familiar with the above word then surely you might have worked on some kinds of APIs api testing best practices in your backend application. Maybe a payment gateway API, Google Maps API, Sending an Email APIs, or any other kind of APIs depending on the type of application and the requirements.

What is API Testing and Why Should You Do It?

The nastiest bug I’ve seen in production as an engineer happened at the unit level. If your code suffers defects at the unit level, it’ll propagate to your entire application. A unit test verifies a small portion of your code independently from other modules of your application.

It’s worth mentioning here that we will be testing a “live” API , so it makes things an “integration test”, as opposed to a “unit test”, which would make use of mocks. Integration tests will give us the best confidence in functionality since it’s hitting the real service we’ll integrate with. The trade-offs of course are speed , and not having a predictable state . We could do unit tests by saving the API responses to a JSON file, then mocking HTTP Client to return the mocks.

Final Thoughts on API Testing

Nothing too complicated here, as we are just operating on the in-memory list of books and returning the correct status code & payload given the HTTP Verb in use. If you are a client for an API, which means you use an external API within your system, you should not only rely on documentation but also make sure that API works as expected . Sometimes, there is only pure or outdated documentation that doesn’t describe all the components of the API. So you need to make some hypotheses and check them by API testing. Because APIs are frequently faster and lend themselves well to automated testing, it’s generally advantageous to use them for test automation. We often consider test automation to be only an extension of our exploratory testing, and exploratory testing certainly provides insight into what we need to automate.

One of the most important items that you should be testing for is how the API handles problems when they do come up. First of all, does it crash, or does it actually handle the problem? Needless to say, under ordinary circumstances, you should never ship anything that’s capable of blue-screening the operating system — but it does happen. As with any other kind of software, if an API fails, it should fail gracefully, shutting itself down, displaying the appropriate system messages, and letting go of any processes.

In spite of this fact, many software testers continue to automate their testing with user interface -based tests that interact directly with the browser. This is largely due to the success of the Selenium suite of tools for test automation, which runs in a web browser. A smoke test is a fast, easy way of validating the code of an API to ensure that it functions as intended on a basic level. This may involve checking if the API responds to calls, responds correctly, or interacts properly with other components. Keeping the API testing schema updated—the schema consists of data formatting and storage, including API requests and responses. Enhancements to the program, which can generate additional parameters for API calls, must take into account the configuration of the schema.

With the evolution of APIs, however, various standards and new approaches surfaced. needs to review the security of your connection before proceeding. Update the question so it can be answered with facts and citations by editing this post. Automation is more about doing the same thing over and over again. In order to be implemented, automation relies on exploration. So, if we need to automate something, what exactly do we need to automate?

If the endpoint changes, they will be provided with the new one, without the need to change the client code. By flexibility, I mean that it’s easy to modify and it’s also able to answer many clients who can ask for different data types . Since the server is stateless and each request can be processed individually, GET requests should usually return the same response regardless of previous ones and the session. Caching is a critical factor for the scalability and performance of a modern web application.