Nested object assertions in Postman

Introduction

We use nested object assertions to check values inside objects within objects. This helps us make sure all parts of complex data are correct.

When testing API responses that have objects inside other objects.

When you want to verify a user's address details inside a user profile object.

When checking product details that include nested specifications.

When validating configuration settings that are grouped in nested objects.

Syntax

Postman

pm.test('Test name', function () {
    pm.expect(responseJson.parent.child).to.eql(expectedValue);
});

Use dot notation to access nested properties.

Use pm.expect() with .to.eql() to compare values deeply.

Examples

This checks that the city inside the address object of user is 'New York'.

Postman

pm.test('Check user city', function () {
    pm.expect(responseJson.user.address.city).to.eql('New York');
});

This verifies the price inside the details object of product is 29.99.

Postman

pm.test('Verify product price', function () {
    pm.expect(responseJson.product.details.price).to.eql(29.99);
});

Sample Program

This test script checks two nested properties: city and zip inside the user's address object.

Postman

const responseJson = {
    user: {
        id: 1,
        name: 'Alice',
        address: {
            street: '123 Main St',
            city: 'Springfield',
            zip: '12345'
        }
    }
};

pm.test('User city is Springfield', function () {
    pm.expect(responseJson.user.address.city).to.eql('Springfield');
});

pm.test('User zip code is 12345', function () {
    pm.expect(responseJson.user.address.zip).to.eql('12345');
});

Important Notes

Always check that the nested path exists before asserting to avoid errors.

Use descriptive test names to know which nested property failed if test fails.

Summary

Nested object assertions help verify deep data inside complex responses.

Use dot notation to access nested properties clearly.

Write clear tests to catch errors in specific nested fields.