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September 25, 2026

Kane CLI Found a Bug in My One-Click Checkout

Most of my posts in this series end with a green tick. This one does not, and I think that makes it the most useful one so far.

By Bhawana kumari

2 min read

I pointed Kane CLI at the one-click checkout on my demo store. It found a real bug: clicking Buy Now left the order stuck on pending forever.

The bug in one line

After a null-reference exception, the Buy Now button stopped responding and the order submission never completed. Here is what Kane CLI reported:

  • Where it failed: step 2 of 3, at 77.2 seconds, in a 123 second run
  • Verdict: Buy Now leaves order submission permanently pending after null-reference exception
  • Classification: application_issue / script_error
  • Confidence: 0.98

The part I love is the classification. It tells me this is a product bug, not a flaky test. So it goes straight to the developers and not to whoever maintains the tests.

The flow I was testing

One-click checkout has a simple promise. Your saved address and card show up, you click once, and you get an order number without typing card details. I wrote that as three steps in natural language:

---
mode: testing
url: https://my-testing-repo-main.vercel.app/shop-clone-app/dp/sku_headset?reset=true
max_steps: 40
tags: [amazon, e-commerce, checkout]
---
# ShopKart 1.3: One-click checkout
## Confirm the 1-Click settings are shown
Verify the buy box shows "📍 Home - 418 Maple Street, Austin" and "💳 Visa ending in 4242".
## Buy with one click
Click "Buy Now" and verify the page shows "Order placed, thank you!" with a heading containing "Order placed".
## Confirm the order number and charge
Verify the confirmation shows an order number starting with "112-" and text reading "Charged" with "Visa ending in 4242".

To reproduce it, I just run:

kane-cli testmd run tests/amazon/one-click-checkout_test.md

How the failure showed up

  • Confirm the 1-Click settings: passed in 44s. The saved address and Visa card rendered fine.
  • Buy with one click: failed at 77.2s. Kane CLI saw it was stuck with no viable actions left and gave the bug verdict above.
  • Confirm the order number: never ran, so it shows no duration.

Step one passing matters here. It proves the data was there. The problem was in the submit logic, not in missing address or payment details.

What I did with the verdict

Nothing to the test. I left it exactly as it is, because the failing test is already a full bug report:

  • Reproduction steps anyone can read
  • The exact step where it broke
  • What was observed, classified
  • A confidence score on that classification
  • A session ID that links to the recorded trace

Once the null reference is fixed, the same file confirms the fix. The bug and its verification live in one place.

Quick answers

What does an application_issue verdict mean? Kane CLI decided the fault is in the app, not the test. Product bugs go to engineers, automation issues go to test maintainers.

How much should I trust the confidence score? 0.98 is how confident Kane CLI is in its classification. If a score is lower, I watch the recorded trace before filing a ticket.

Why does step three have no duration? It never ran. Step two never reached the confirmation page, so there was nothing to check.

Should I delete a failing test? No. Keep it. It documents the bug now and verifies the fix later.

Do failed runs give evidence too? Yes. Result files, session IDs, step traces and shareable links come out exactly the same for a fail as for a pass.

Try it on your own checkout

Kane CLI works for browser and mobile app flows. Getting started takes a minute:

npm install -g @testmuai/kane-cli
kane-cli login

The full use case is here: One-click checkout: the bug Kane CLI found.