1 Document the API Testing Requirements
What is API Testing?
API testing is a type of software testing where application programminginterfaces (APIs) are tested to determine if they meet expectations forfunctionality, reliability, performance, and security.In simple terms, API testing is intended to reveal bugs, inconsistencies ordeviations from the expected behavior of an API. Commonly, applications havethree separate layers: * Presentation Layer or user interface * Business Layer or application user interface for business logic processing * Database Layer for modeling and manipulating dataAPI testing is performed at the most critical layer of software architecture,the Business Layer. It is in the business layer, business logic processing iscarried out, and all transactions between User Interface(UI) and databasehappen. So, making sure that, API offers complete intended functionalityallows for easy future expansion of the software product. More reasons as towhy API testing is important are discussed next in this ‘What is API Testing?’article.
Why should we do API Testing?
API testing is an important activity that testing teams should focus on. Itoffers a number of advantages over other kinds of testingLanguage Independent: Data is exchanged via XML and JSON, so any language canbe used for automation, independent from the languages used to develop theapplication.GUI Independent: API testing can be done to check the core functionality ofthe application to expose small errors and to evaluate a build’s strength.Also, we can test the APIs without a user interface.Improved Test Coverage: Most API’s have features, that allow a tester tocreate automated tests with high test coverage including positive and negativecases. We can rarely find test cases that can’t be automated.Reduce Testing Cost: With API testing we can find minor bugs before the GUItesting. Usually, these minor bugs will become bigger during GUI testing. Sofinding those bugs while performing API testing will be cost effective.Enables Faster Releases: The test cases that take about 8-10 hrs whenexecuting UI regression testing take only about 1-2 hrs with API testing. Thisallows companies to release builds faster with API testing.So, API testing is a really important phase of the testing process. But how isAPI testing carried out? Is there a specific procedure?
How to Perform API Testing?
Listed below are the steps that you can follow to perform API testing:API Specification ReviewThe first step is documenting the API testing requirements. What is thepurpose of the API? What is the workflow of the application? Whichintegrations are supported by the API? What are the features of the API?Documenting all these API testing requirements is the first thing you need todo. This will help you in planning API tests throughout the testing process.Setting Up Test EnvironmentNext step is setting up a testing environment, with the required set ofparameters around the API. This involves configuring the database and serverfor the application requirements.Integrating Application DataIn this step, you need to combine your application data with the API tests toensure that the API functions as expected against all possible inputconfigurations.Deciding Type of API TestAfter you’ve created the testing boundaries and requirements, you need todecide what you want to test your API for. There are different types of APItests like functionality testing, validation testing, load testing, securitytesting, end-to-end testing, fuzz testing and many more. More about APItesting types in the next session of this article.Text Execution & ReportingOnce you have decided on what to test the API for, the next step obviously isto create test cases around that requirements and execute them. A basicguideline is to identify the most common parameters and conditions that an enddeveloper will use when calling the APIs and test these scenarios extensively.And then document the test results for further use.Well, you can follow the above steps to successfully test APIs. One of theimportant steps while performing API tests is to decide what kind of test youwant to perform. For that, you should be aware of the types of API testing.Let’s check them out next in this ‘What is API Testing’ article.
Types of API Testing
In API testing, the following types of testing can be conducted: * Functionality Testing – To check if the API works and does exactly what it’s supposed to do * Reliability Testing – To check if API can be consistently connected to and lead to consistent results * Validation Testing – Helps verify the aspects of product, behavior, and efficiency of an API * Load Testing – Is performed to ensure the performance of API under both normal and at peak conditions * UI Testing – It involves testing the user interface for the API and other integral parts * Security Testing – To test that the API is secure against all possible external threats * Penetration Testing – To detect vulnerabilities of an application from an attackers perspective * Fuzz Testing – To test the API in terms of the limits to prepare for the “worst case scenarios”Well, these are the most frequently performed API test types. By performingthese tests what are you trying to test for? What will you find?You are checking for: * Duplicate or missing functionality * Improper messaging * Error handling mechanism is incompatible * Multi-threaded issues * Security, performance & security issues * Reliability issuesSince API Testing is gaining popularity, we have many tools available for thesame. This ‘What is API Testing?’ article lists some popular API testing toolsfor your reference.
API Testing Tools
For successfully performing API testing, you will need a tool to structure andmanage your test cases. Here are some of the top API testing tools that can beused for Rest API and Soap API:SoapUI: It is the most widely popular open-source tool for API testing. WithSopaUI you can perform functional testing, performance testing, securitytesting, and data-driven testing. It will provide you with the reports fortesting and will allow you to export the data.Postman: With more than 4 million users worldwide it is one of the mostpopular API testing tools. It runs on Mac, Windows, Linux & Chrome Apps.Allows you to set up all the headers and cookies your API expects, and thencheck the response.Katalon Studio: It is a robust and comprehensive automation tool for API, Web,and mobile testing. Provides easy deployment by including all frameworks, ALMintegrations, and plugins in one package. Also, supports both SOAP and RESTrequests,also supports various types of commands and parameterizationfunctionalities.Tricentis Tosca: It is a model based test API automation testing tool fromTricentis but also supports API testing. It supports a wide array of protocolsincluding HTTP(s) JMS, SOAP, REST, IBM MQ, NET TCP, etc.REST-assured: It is an open-source Java Domain-specific language (DSL) toolthat makes testing REST service simple. Supports XML and JSON requests. Thistool simplifies things by eliminating the need to use boiler-plate code totest and validate complex responses.Apart from these popular tools, there are also tools like Apache JMeter,HttpMaster, Parasoft, HP QTP, Karate DSL, and many others. Though these toolsmake API testing easy, you might still come across some challenges whileperforming API testing.
Challenges of API Testing
* There is no GUI, which will make it difficult for testers to give input values * Test case management is difficult since a tester might have to deal with millions of test cases * The tester must possess expertise in the programming language(s) that are targeted by the API * Time-consuming, requires a lot of time and resources to develop tools and design tests * Improper documentation will make it difficult for a test designer to understand the purpose of API calls * Proper call sequencing is required as this may lead to inadequate coverage in testing * Exception handling functions need to be tested thoroughlyRegardless of the challenges that we might come across API testing is quitecrucial and highly required. If an API breaks because errors weren’t detected,there is the threat of not only breaking a single application but an entirechain of business processes hinged to it. With this, we have reached the endof this ‘What is API Testing?’ article.If you found this “What is API Testing?” article relevant, check out the live-online Selenium Certification Training by Edureka, a trusted online learningcompany with a network of more than 250,000 satisfied learners spread acrossthe globe.Got a question for us? Please mention it in the comments section of this ‘Whatis API Testing?” article and we will get back to you.API Testing Guide and Beginner’s Tips (SOAP & REST)
10. Do not underestimate API automation testing
API testing flow is quite simple with three main steps: * Send the request with necessary input data * Get the response having output data * Verify that the response returned as expected in the requirementThe most touch parts of API testing are not either sending request norreceiving the response. They are test data management and verification. It iscommon that testing a few first APIs such as login, query some resources, etc.is quite simple. The testing task becomes more and more difficult to furtherAPIs. Therefore, API testing task is easy to be underestimated. At some pointin time, you would find yourself in the middle of choosing a good approach fortest data and verification method. It is because the returned data havesimilar structures, but not the same in a testing project. It will bedifficult to decide if you should verify the JSON/XML data key by key, orusing object mapping to leverage the power of programming language.Considering API automation testing a real development project is highlysuggested. It should be structured to be extendable, reusable, andmaintainable.Author: Trong Bui – QA Architect at KMS Technology10 Simple API Testing Tips for Beginners (SOAP & REST)API (application programming interface) testing is a type of software testingthat performs verification directly at the API level. It is a part ofintegration testing that determines whether the APIs meet the testers’expectations of functionality, reliability, performance, and security. UnlikeUI testing, API testing is performed at the message layer without GUI.There are two broad classes of web service for Web API: SOAP and REST. SOAP(Simple Object Access Protocol) is a standard protocol defined by the W3Cstandards for sending and receiving web service requests and responses. REST(Representational State Transfer) is the web standards-based architecture thatuses HTTP. Unlike SOAP-based Web services, there is no official standard forRESTful Web APIs.Here are 10 basic tips that you need to know for API testing:
10. Do not underestimate API automation testing
API testing flow is quite simple with three main steps: * Send the request with necessary input data * Get the response having output data * Verify that the response returned as expected in the requirementThe most touch parts of API testing are not either sending request norreceiving the response. They are test data management and verification. It iscommon that testing a few first APIs such as login, query some resources, etc.is quite simple. The testing task becomes more and more difficult to furtherAPIs. Therefore, API testing task is easy to be underestimated. At some pointin time, you would find yourself in the middle of choosing a good approach fortest data and verification method. It is because the returned data havesimilar structures, but not the same in a testing project. It will bedifficult to decide if you should verify the JSON/XML data key by key, orusing object mapping to leverage the power of programming language.Considering API automation testing a real development project is highlysuggested. It should be structured to be extendable, reusable, andmaintainable.Top tools for API testing in 2020
What is API testing
APIs are becoming the preferred method of communication between web componentsand this has the effect of driving the business logic farther into theirimplementation. This means that APIs need to be tested to catch and re-mediatebugs before they reach production.API testing is a type of software testing that directly tests the applicationprogramming interface to determine if it correctly responds to requests, meetsfunctionality, performance and security standards.API testing is sometimes called “headless” testing because it usually teststhe behavior of a User interface (UI) without actually interacting with orloading the UI, but by sending requests directly to the backend API.
Benefits of API testing
API testing promises several benefits that can impact the efficiency of thetest suite positively. A notable benefit of API testing is that it is capableof quickly catching bugs in the test cycle, and this is useful in giving quickfeedback to developer teams.API tests are also a better choice when compared to UI tests as the latter canbe slow to implement and can result in flaky results.
Some awesome free tools for API testing
There are several ways to go about API testing, one of which is directlywriting code in your preferred language to hit the endpoints and confirm thatthe response and data are in-line with expectations. As with everything elsein software development, there are dedicated tools to automate the process andmake things significantly easier and faster.We are going to look at some awesome tools that simplify the process of APItesting and make it easy to reuse the same tests with different API services.
1. Document the API Testing Requirements
Each testing involves the initial part as requirements gathering. Thus, beforecreating API test cases, it is highly important to understand details aboutthe application like: * What is the purpose of this API? * What is the workflow of the application? Give an overview of the complete application architecture. * What are the integrations supported by the API? Give examples of types of applications and systems along with technology, environment, and platform. * What are the features and functions of the API?Documenting all these API testing requirements is the first thing we need toimplement. This will help us in planning API tests throughout our wholetesting process.Frankly speaking, I have seen certain QA teams omit this part of documenting,which results in fuzziness about the requirements. This often creates breakupsbetween hardworking teams, which is not at all acceptable when trying toachieve greater results.
2. Set the Output of the API Tests
Once, we have gathered and documented the API testing requirements, we can nowmove towards finalizing the output of the API tests. The output of the APItests can vary from pass/fail status to any relevant or invalid data or a callto some other API. Here, I should not leave out that there are times whenthere are no outputs in certain tests. It can be tricky, as well as risky, tomeasure the results of the tests with the expected outcome. However, askingthe following questions can really help.Have you ever found specifying the output to be challenging?What can be done in this situation?What if the output is the out-of-the-box kind?