Answer
Test Scripts in Postman
Test scripts run after a response is received. They are written in JavaScript and use Postman''s pm API to validate API responses.
Location
▸Tests tab → bottom panel of any request
Common Test Assertions
Status Code Checks
JavaScript
// Check status code is 200
pm.test("Status code is 200", function () {
pm.response.to.have.status(200);
});
// Check status code is in range 2xx
pm.test("Success status", function () {
pm.expect(pm.response.code).to.be.oneOf([200, 201, 204]);
});
Response Body Assertions
JavaScript
// Parse JSON body
const jsonData = pm.response.json();
pm.test("User name is correct", function () {
pm.expect(jsonData.data.first_name).to.eql("Janet");
});
pm.test("ID exists", function () {
pm.expect(jsonData.data.id).to.be.a("number");
});
pm.test("Email format", function () {
pm.expect(jsonData.data.email).to.include("@");
});
Response Time Check
JavaScript
pm.test("Response time is under 500ms", function () {
pm.expect(pm.response.responseTime).to.be.below(500);
});
Header Validation
JavaScript
pm.test("Content-Type is JSON", function () {
pm.expect(pm.response.headers.get("Content-Type")).to.include("application/json");
});
Save Values for Chaining
JavaScript
pm.test("Save user ID", function () {
const jsonData = pm.response.json();
pm.environment.set("user_id", jsonData.data.id);
});
Quick Snippets
Postman provides code snippets in the right panel of the Tests tab:
- ✓"Status code: Code is 200"
- ✓"Response body: JSON value check"
- ✓"Response time is less than 200ms"
- ✓"Response headers: Content-Type header check"
Click any snippet to insert it automatically!