Can the buyer finish checkout?
Sauce Demo publishes test accounts, including accounts with deliberately faulty behavior. We used synthetic buyer information and its simulated checkout. No real purchase, payment or customer data was involved.
Scope and decision
One journey: sign in → add one backpack → cart → buyer information → overview → simulated order completion. The standard account completed this journey. The problem account was blocked at buyer information. An equivalent production behavior would block release for the affected journey until corrected and retested.
Environment: Chromium 151.0.7922.137 on Linux, headless Playwright, 1280 × 800 desktop viewport. Recorded at 2026-09-10 01:22 UTC (9 September, 22:22 in Buenos Aires). This report does not claim mobile or multi-browser coverage.
Download recorded results (JSON) · Earlier image/login demonstration
What passed
| Check | Observed evidence |
|---|---|
| Add one item | Cart badge changed to 1. Cart showed one Sauce Labs Backpack at $29.99. |
| Required-field validation | Continuing with empty buyer information stayed on step one and showed “Error: First Name is required”. |
| Valid buyer information | standard_user accepted Demo / Tester / 1000 and advanced to the checkout overview. |
| Displayed arithmetic | $29.99 item total + $2.40 displayed tax = $32.39 total. Tax policy and jurisdiction were not validated. |
| Simulated completion | Finish reached checkout-complete.html with a thank-you message; cart badge was absent. |
Entering the surname changes the first name and leaves checkout blocked
Account: problem_user. The same input sequence passed with standard_user. Both are published demo accounts, not private credentials.
Reproduction
- Start a fresh session on Sauce Demo; sign in with its published problem_user account and demo password.
- Add Sauce Labs Backpack, open the cart and select Checkout.
- Fill First Name with “Demo”, Last Name with “Tester”, and Postal Code with “1000”, in that order.
- Inspect the field values, then select Continue.
Expected: First Name stays Demo, Last Name contains Tester, and valid information advances to the overview.
Actual: First Name became Tester, Last Name remained empty, and Continue displayed a last-name-required error. The page remained on checkout-step-one.html.
Attempted input Observed value First Name: Demo Tester Last Name: Tester [empty] Postal Code: 1000 1000 Error: Last Name is required
Impact: the tested account cannot progress through this checkout attempt. Production prevalence, revenue impact and alternative workarounds were not measured. High severity here illustrates a blocked core journey, not a security rating.
Suggested investigation: inspect how changes to the last-name input update form state, including account-specific behavior. Confirm the handler targets the correct field. This is a hypothesis for the developer; source code and root cause were not inspected.
Retest acceptance
- Each field retains its own entered value when edited.
- Valid buyer information advances to the overview for the affected account.
- An actually empty last name still triggers the required-field validation.
- The standard-account journey continues to pass.
No correction was made, so this finding has not been retested after a fix.
Validation evidence
Boundaries of this review
Not tested: physical devices, mobile layouts, Firefox/Safari, inventory persistence, multiple products, remove/cancel flows, actual payment processing, order fulfilment, email delivery, authentication security, accessibility compliance, performance or production integrations. Passing the simulated order flow does not validate a real store's payments.
This sample demonstrates how Probalo distinguishes a working path from a reproducible blocker. A paid engagement uses the client's agreed journey, access permissions and browser coverage. Findings are not padded to meet a minimum count.