JSON Schema validation in Postman - Test Execution Trace

Test Overview

This test checks if the API response matches the expected JSON schema. It verifies the structure and data types of the response fields.

Test Code - Postman

Postman

pm.test('Response matches JSON schema', () => {
  const schema = {
    type: 'object',
    properties: {
      id: { type: 'integer' },
      name: { type: 'string' },
      email: { type: 'string', format: 'email' },
      isActive: { type: 'boolean' }
    },
    required: ['id', 'name', 'email', 'isActive'],
    additionalProperties: false
  };
  pm.response.to.have.jsonSchema(schema);
});

Execution Trace - 4 Steps

Step	Action	System State	Assertion	Result
1	Test starts	Postman test runner is ready to execute the test script	-	PASS
2	Send API request and receive response	Response received with JSON body containing id, name, email, and isActive fields	-	PASS
3	Validate response JSON against the defined schema using pm.response.to.have.jsonSchema	Response JSON is checked for correct types and required fields	Check that id is integer, name is string, email is valid email string, isActive is boolean, and no extra fields exist	PASS
4	Test completes with assertion result	Test runner shows test passed if schema validation succeeded	Schema validation passed	PASS

Failure Scenario

Failing Condition: Response JSON does not match the schema, e.g., missing required field or wrong data type

Execution Trace Quiz - 3 Questions

What does the test verify in the API response?

A The response matches the expected JSON schema

B The response time is less than 2 seconds

C The response status code is 404

D The response contains a specific header

Key Result

Validating API responses against a JSON schema ensures the data structure and types are correct, preventing errors in later processing.