Types of Defects during API Testing

Summary

In this video, the speaker delves into the various types of defects that can arise during API testing, particularly when testing APIs using Postman and JSON schema validation. Key topics include identifying issues related to status codes, missing or improperly formatted data, invalid headers, and null checks. The speaker emphasizes the importance of performance testing by verifying response times and ensuring APIs meet performance standards. Additionally, the video covers how to use JSON schema validation to streamline defect detection. The speaker concludes with recommendations to check out additional learning resources on API testing.

Takeaways

• 😀 Ensure to check various API response status codes for both positive and negative test cases, especially when applying boundary values.
• 😀 Verify that the JSON response is formatted correctly, with all necessary keys present, and check for missing or improperly formatted data.
• 😀 Validate data types in the API response to ensure they match the expected values, and check for null values or empty data where they shouldn't exist.
• 😀 Ensure proper headers handling in API requests and responses. Missing or incorrectly configured headers are common defects.
• 😀 Perform null checks to ensure that no essential data is missing or null in the API response.
• 😀 Verify that API responses meet performance standards, such as the response time being under a specified threshold (e.g., 10 seconds).
• 😀 Validate the response body to ensure it is not null and contains the expected data.
• 😀 Ensure that the authentication mechanism works correctly and that authentication failures are handled properly.
• 😀 Use JSON schema validation to check the structure, data types, and format of the API response, which helps identify many common defects.
• 😀 The GitHub API can be used as an example for writing test cases, including Postman tests, to validate API responses using JSON schema.
• 😀 Learn more about API testing by checking out relevant resources and playlists, such as the Testing Academy's full API testing with Postman and REST Assured tutorial.

Q & A

What is the main focus of this video script?

The video focuses on identifying different types of defects in API testing, including common errors found during testing, validation techniques, and tools like JSON schema validation to ensure proper API behavior.

Why is status code verification important in API testing?

Status code verification is crucial because it helps ensure that both positive and negative test cases return the expected responses, allowing testers to identify errors when the API does not behave as expected under different conditions.

What are the six combinations to check when testing API boundary values?

The six combinations to check are: maximum value, minimum value, maximum boundary value, minimum boundary value, and two other combinations involving values from the start and end of the range.

What type of defects are commonly found when checking API responses?

Common defects include missing or incorrect keys, invalid data types, null values where they should not be, improperly formatted data, and unstructured or invalid JSON responses.

What are the key factors to check when analyzing API response headers?

When analyzing API response headers, it's important to verify that the correct headers are present, such as content type, authorization, and any other headers that are necessary for the API to function correctly. Incorrect or missing headers can cause defects.

How can you verify that the API response is properly formatted?

One way to verify proper formatting is by using JSON schema validation, which checks if the response adheres to the correct structure, includes necessary keys, and uses appropriate data types.

What is the significance of time taken in API testing?

The time taken by an API to respond is critical in performance testing. For instance, an API should return a response within a reasonable time, such as under 10 seconds in production. If it exceeds this, it can indicate a performance issue or defect.

What is a potential defect related to null values in API responses?

A defect occurs when an API response unexpectedly contains null values for fields that should have data, potentially causing the application to fail or behave unpredictably.

What is the role of JSON schema validation in API testing?

JSON schema validation helps ensure that the API responses adhere to a predefined structure, with correct data types, necessary keys, and proper formatting. It can identify issues like missing keys or improperly structured JSON data.

Why should you include time validation in your API test cases?

Time validation ensures that the API responds within acceptable limits, such as within a few seconds. If the response time is too long, it might indicate a performance issue that could affect user experience.