API Test Cases

What to Cover

• Positive cases: valid input returns the expected status code and correct data.
• Negative cases: invalid input (missing fields, wrong data types) returns appropriate error codes and messages.
• Boundary cases: testing limits, such as maximum field length or pagination edges.
• Authentication/authorization: requests without valid credentials are correctly rejected.
• Response structure: confirming the response schema, data types, and required fields are correct.

Example Test Case

For a GET /users/{id} endpoint: input — a valid existing user ID; expected result — status code 200 and a response body containing the correct user's name and email.