…or non stackable offer
<!--
Make sure you've read the CONTRIBUTING.md guidelines:
https://github.com/stack-auth/stack-auth/blob/dev/CONTRIBUTING.md
-->
<!-- RECURSEML_SUMMARY:START -->
## High-level PR Summary
This PR improves error messaging in the payments system by addressing
two main issues: (1) providing clearer error messages when an item ID is
mistakenly used as a product ID, including distinguishing between
non-existent products, server-only products, and cases where an item
exists with that ID, and (2) preventing checkout creation for
non-stackable products that a customer already owns by adding an early
validation check. The changes update the `ProductDoesNotExist` known
error to include contextual information, introduce a new
`getCustomerPurchaseContext` helper function to check existing
purchases, and update related test snapshots to reflect the improved
error messages.
⏱️ Estimated Review Time: 15-30 minutes
<details>
<summary>💡 Review Order Suggestion</summary>
| Order | File Path |
|-------|-----------|
| 1 | `packages/stack-shared/src/known-errors.tsx` |
| 2 | `apps/backend/src/lib/payments.tsx` |
| 3 |
`apps/backend/src/app/api/latest/payments/purchases/create-purchase-url/route.ts`
|
| 4 |
`apps/e2e/tests/backend/endpoints/api/v1/payments/create-purchase-url.test.ts`
|
| 5 |
`apps/e2e/tests/backend/endpoints/api/v1/payments/before-offer-to-product-rename/outdated--create-purchase-url.test.ts`
|
</details>
[](https://discord.gg/n3SsVDAW6U)
[
<!-- RECURSEML_SUMMARY:END -->
<!-- ELLIPSIS_HIDDEN -->
----
> [!IMPORTANT]
> Enhances payment error handling by adding context to error messages
and preventing duplicate purchases of non-stackable products.
>
> - **Behavior**:
> - Adds early validation in `create-purchase-url/route.ts` to prevent
checkout for non-stackable products already owned by the customer.
> - Updates `ensureProductIdOrInlineProduct` in `payments.tsx` to
include context in `ProductDoesNotExist` error.
> - Introduces `getCustomerPurchaseContext` in `payments.tsx` to check
existing purchases.
> - **Errors**:
> - Modifies `ProductDoesNotExist` in `known-errors.tsx` to include
`context` (null, server_only, item_exists).
> - **Tests**:
> - Updates test cases in `create-purchase-url.test.ts`,
`purchase-session.test.ts`, and `validate-code.test.ts` to reflect new
error messages and behavior.
> - Adds tests for blocking repeat purchases of non-stackable products.
>
> <sup>This description was created by </sup>[<img alt="Ellipsis"
src="https://img.shields.io/badge/Ellipsis-blue?color=175173">](https://www.ellipsis.dev?ref=stack-auth%2Fstack-auth&utm_source=github&utm_medium=referral)<sup>
for 5495b9c269. You can
[customize](https://app.ellipsis.dev/stack-auth/settings/summaries) this
summary. It will automatically update as commits are pushed.</sup>
----
<!-- ELLIPSIS_HIDDEN -->
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
- New Features
- Blocks creating a purchase URL when a customer already owns a
non-stackable product, preventing duplicate checkouts.
- Bug Fixes
- Standardized error responses for missing or server-only products with
consistent codes, messages, and structured details.
- Error payloads now include details.context (null, server_only, or
item_exists) instead of access_type.
- Tests
- Added and updated tests to cover blocking repeat purchases and the new
standardized error format (including inline snapshot updates).
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
---------
Co-authored-by: Konsti Wohlwend <n2d4xc@gmail.com>
d37b7ea7c8