API test tools overview in Testing Fundamentals - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an API testing tool?

An API testing tool helps testers check if an API works correctly by sending requests and checking responses automatically.

beginner

Name a popular API testing tool.

Postman is a popular API testing tool that lets you create, send, and automate API requests easily.

intermediate

What is the main difference between Postman and SoapUI?

Postman is mainly for REST APIs and easy to use, while SoapUI supports both REST and SOAP APIs and offers advanced testing features.

beginner

Why use automated API testing tools instead of manual testing?

Automated tools save time, reduce human errors, and can run many tests quickly, making testing more reliable and efficient.

intermediate

What feature should you look for in an API testing tool?

Look for easy request building, response validation, support for different API types, automation options, and good reporting.

Which API testing tool is known for its user-friendly interface and is widely used for REST APIs?

A SoapUI

B Postman

C JMeter

D Selenium

Postman is popular for its easy-to-use interface and strong support for REST API testing.

Which API testing tool supports both REST and SOAP protocols?

A Postman

B Jest

C SoapUI

D Cypress

SoapUI supports testing for both REST and SOAP APIs.

What is a key benefit of using automated API testing tools?

A They require no setup

B They eliminate the need for developers

C They replace manual testing completely

D They run tests faster and reduce errors

Automated tools speed up testing and reduce human mistakes but do not replace manual testing entirely.

Which feature is NOT typically important in an API testing tool?

A Video editing

B Response validation

C Request building

D Automation support

Video editing is unrelated to API testing tools.

JMeter is mainly used for:

A Performance and load testing including APIs

B API functional testing only

C UI testing

D Database management

JMeter is popular for performance and load testing, including APIs.

Explain what an API testing tool does and why it is useful.

Think about how you check if a website works but for APIs.

List three popular API testing tools and one key feature of each.

Remember tools that help with different API types and testing needs.

Practice

1. Which of the following is a popular tool used for manual API testing with a user-friendly interface?

easy

A. Selenium

B. JUnit

C. Postman

D. JMeter

Solution

1. Step 1: Identify tools for API testing

   Postman is widely known as a manual API testing tool with a graphical interface.

2. Step 2: Differentiate from other tools

   JUnit is for unit testing, Selenium for UI testing, and JMeter for performance testing, not primarily manual API testing.

3. Final Answer:

   Postman -> Option C

4. Quick Check:

   Manual API testing tool = Postman [OK]

Hint: Postman = manual API testing with GUI [OK]

Common Mistakes:

• Confusing JUnit as an API testing tool
• Thinking Selenium is for API testing
• Assuming JMeter is mainly for API functional testing

2. Which command-line tool is commonly used to send HTTP requests for API testing?

easy

A. docker

B. npm

C. git

D. curl

Solution

1. Step 1: Identify command-line tools related to HTTP requests

   curl is a command-line tool designed to send HTTP requests and test APIs.

2. Step 2: Exclude unrelated tools

   npm manages Node.js packages, git manages source code, and docker manages containers, none are for HTTP requests.

3. Final Answer:

   curl -> Option D

4. Quick Check:

   Command-line HTTP tool = curl [OK]

Hint: curl sends HTTP requests from terminal [OK]

Common Mistakes:

• Confusing npm with API testing
• Thinking git can send HTTP requests
• Assuming docker is for API calls

3. Consider this REST-assured Java code snippet for API testing:

given().when().get("https://api.example.com/users/1").then().statusCode(200);

What does this test check?

medium

A. The API returns status code 200 for user with ID 1

B. The API returns a list of all users

C. The API creates a new user

D. The API returns status code 404 for user with ID 1

Solution

1. Step 1: Analyze the HTTP method and URL

   The code uses GET on endpoint /users/1, which typically fetches user with ID 1.

2. Step 2: Check the assertion on status code

   The test expects the response status code to be 200, meaning success.

3. Final Answer:

   The API returns status code 200 for user with ID 1 -> Option A

4. Quick Check:

   GET /users/1 expects 200 = The API returns status code 200 for user with ID 1 [OK]

Hint: GET + statusCode(200) means successful fetch [OK]

Common Mistakes:

• Thinking it creates a user (POST needed)
• Assuming it fetches all users (no list endpoint)
• Confusing 404 with 200 status code

4. You wrote this curl command to test an API:

curl -X GET https://api.example.com/data -d '{"id":5}'

What is wrong with this command?

medium

A. GET requests should not have a request body (-d option)

B. The URL is missing the protocol

C. The HTTP method should be POST, not GET

D. The JSON data is missing a closing brace

Solution

1. Step 1: Understand HTTP GET request rules

   GET requests usually do not have a body; sending data with -d is ignored or causes errors.

2. Step 2: Check other parts of the command

   The URL includes protocol https://, JSON is properly closed, and GET is valid method for fetching data.

3. Final Answer:

   GET requests should not have a request body (-d option) -> Option A

4. Quick Check:

   GET with body (-d) is invalid [OK]

Hint: GET requests don't send data in body (-d) [OK]

Common Mistakes:

• Thinking URL lacks protocol
• Assuming POST is required here
• Missing JSON brace (actually present)

5. You want to automate API tests that check multiple endpoints with different HTTP methods and validate JSON responses. Which tool is best suited for this task?

hard

A. Postman manual runner

B. REST-assured

C. curl command line only

D. Browser developer tools

Solution

1. Step 1: Identify automation needs

   Testing multiple endpoints with various HTTP methods and validating JSON requires scripting and assertions.

2. Step 2: Match tool capabilities

   REST-assured is a Java library designed for automated API testing with rich validation support.

3. Step 3: Exclude less suitable tools

   Postman manual runner is not fully automated, curl lacks built-in assertions, and browser tools are for debugging, not automation.

4. Final Answer:

   REST-assured -> Option B

5. Quick Check:

   Automated API testing with assertions = REST-assured [OK]

Hint: REST-assured = automated API tests with assertions [OK]

Common Mistakes:

• Choosing Postman manual runner for automation
• Using curl without assertion support
• Relying on browser tools for automated tests