# SF-BUG-001: Multiple notebooks show a one-notebook line total

- Project: ShopFlow — independent guided manual QA and UX practice.
- Status: Verified for the documented two-unit Add and three-unit Update cases on release 1.1. Original failures remain documented on 1.0; broader regression pending.
- Tests / runs: SF-TC-002 / SF-RUN-001 and SF-TC-010 / SF-RUN-002.
- Requirements: SF-REQ-03 (unit price × quantity and subtotal), SF-REQ-08 (final total).
- Environment: Release 1.0 confirmed in screenshot; Windows desktop, Chrome confirmed by session context. Browser version not recorded.
- Record date: October 14, 2026.

## Setup and reproduction

The guided procedure requested an empty release 1.0 cart, Standard delivery, and no promo. The screenshot confirms a cart containing only Workshop notebook, quantity 2, with Standard and no active promo.

1. Select ShopFlow release 1.0 and reset it for an empty cart.
2. Enter 2 in the Workshop notebook catalog quantity field.
3. Click that product's Add to cart once.
4. Inspect the cart quantity, line total, subtotal, delivery, discount, and final total.

## Expected and actual values

| Field | Expected | Actual |
| --- | --- | --- |
| Unit price | $12.50 each | $12.50 each |
| Product types / units | 1 / 2 | 1 / 2 |
| Notebook line total | 2 × $12.50 = $25.00 | $12.50 |
| Merchandise subtotal | $25.00 | $12.50 |
| Discount | $0.00 | $0.00 |
| Standard delivery | $4.99 | $4.99 |
| Final total | $25.00 + $4.99 = $29.99 | $17.49 |

The line total and subtotal are $12.50 too low; the final total is also $12.50 too low. The displayed unit price, quantity count, discount, and delivery charge are correct for this fixture. A unit price does not need to change when the number of units changes; the multiplied line amount does.

## Evidence

- [Learner screenshot](../evidence/session-01/SF-RUN-001_SF-TC-002_v1.0_two-notebooks-calculation.png)
- Learner report: quantity is two but pricing does not update for the added quantity; verdict Fail.
- Scope of observations: One Add execution at quantity 2 and one Update execution to quantity 3. Both show the same pricing discrepancy. These are different cases, not two identical replays. Other products have not been tested by the learner.

## Follow-up observation: Update to quantity 3

Starting from the quantity-2 cart, the learner entered 3 in the existing cart quantity field and clicked Update. They reported the price remained the same as for one notebook.

The [SF-RUN-002 screenshot](../evidence/session-01/SF-RUN-002_SF-TC-010_v1.0_three-notebooks-update.png) confirms release 1.0, three units, and “Cart quantity updated” feedback. The line total and subtotal remain $12.50 instead of **3 × $12.50 = $37.50**. With no discount and $4.99 Standard delivery, total remains $17.49 instead of **$42.49**. Each affected money amount is $25.00 too low for this fixture.

Result: **Fail**. The unit price and quantity update are correct; the multiplied amounts are wrong. This is additional evidence linked to the same calculation defect. A shared code cause is not established by the learner's screenshots alone.

## Impact and proposed triage

A customer could see an inaccurate amount for their selected quantity, and the fictional merchant's order amount could be understated if the same breakdown is used at checkout. Checkout impact has not yet been executed or demonstrated by the learner.

Proposed severity: High for an incorrect core purchase calculation. Proposed priority: P1 under the lab's proposed criteria requiring correct order amounts. These are simulated recommendations.

Record this as one calculation defect with multiple affected displays. The code cause is not claimed from the screenshot alone. Do not create three separate bugs solely because line total, subtotal, and final total are all affected.

## Follow-up

SF-TC-010 / SF-RUN-002 explored Update on the same product and failed as described above. It was a follow-up investigation on 1.0, not a later-release retest.

## Release 1.1 retest: two-unit Add case

The learner recreated the two-notebook fixture on 1.1 and reported total $29.99 with shipping. The [SF-RUN-003 screenshot](../evidence/session-02/SF-RUN-003_SF-TC-002_v1.1_two-notebooks-retest.png) confirms quantity 2, line/subtotal $25.00, discount $0.00, Standard delivery $4.99, and total $29.99. Result: **Pass** for this checked input and action.

| Case | Original 1.0 result | 1.1 retest |
| --- | --- | --- |
| Add two notebooks | Fail, SF-RUN-001 | Pass, SF-RUN-003 |
| Update two to three | Fail, SF-RUN-002 | Pass, SF-RUN-004 |

## Release 1.1 retest: three-unit Update case

The learner reported increasing to three notebooks and updating quantity. The [SF-RUN-004 screenshot](../evidence/session-02/SF-RUN-004_SF-TC-010_v1.1_three-notebooks-update-retest.png) confirms three units, accepted-update feedback, line/subtotal $37.50, discount $0.00, delivery $4.99, and total $42.49. Result: **Pass** for the checked Update fixture.

Both documented failing cases have passing follow-up results on 1.1. Marked verified within this scope. Other products, quantities, and monetary-rule interactions need separate regression checks. No universal calculation-correctness or release acceptance claim is made. See [the retest record](CALCULATION-RETEST.md). No workaround tested.