Return an empty page instead of 500ing on out-of-range wishlist product pages

[gumclaw]

What

Public wishlist product listings (Wishlists::ProductsController#index → WishlistPresenter#paginated_public_items) now return an empty page instead of raising Pagy::OverflowError when the requested ?page= exceeds the total page count.

Why

Sentry GUMROAD-2A — Pagy::OverflowError: expected :page in 1..1; got 2 — has fired 1,614 times for 566 users since March 2026 and is still firing daily. The endpoint is public and unauthenticated: the page number comes straight from the query string, so out-of-range pages arrive constantly (stale bookmarks, crawlers, wishlists whose products were removed between page loads). Each one 500ed.

The repo's global pagy default is overflow: :exception (config/initializers/pagy.rb), and other public paginated presenters already opt out per-call (paginated_installments_presenter.rb uses overflow: :empty_page, affiliated_products_presenter.rb/paginated_utm_links_presenter.rb use :last_page). This applies the same pattern here. :empty_page (not :last_page) so the client's "load more" pagination terminates cleanly with next: nil instead of re-serving the last page's items.

A prior attempt (#4116) rescued the error in the presenter and fell back to page 1; it was closed for inactivity. Pagy's built-in overflow mode is simpler and matches existing convention.

QA steps

1. Create a wishlist with fewer than 20 products.
2. Request https://<seller>.gumroad.com/wishlists/<id>/products?page=2.
3. Before: 500. After: 200 with {"items": [], "pagination": {"page": 2, "pages": 1, "next": null, ...}}.

Test Results

bundle exec rspec spec/presenters/wishlist_presenter_spec.rb — 28 examples, 0 failures. The new spec ("returns an empty page instead of raising when the requested page exceeds the total pages") was proven red against unmodified main before the fix.

Before/After

Not a UI change — valid in-range pages render byte-identical data (all 27 pre-existing presenter specs pass unmodified). Only the out-of-range error path changes from a 500 to an empty JSON page.

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AI disclosure: Generated with Claude Fable 5 (Gumclaw's daily Sentry sweep cron). Instructions: triage top unresolved Sentry issues in the gumroad project, classify, and fix actionable items with red-first tests per the repo's contribution gates.

[gumclaw]

Self-review (fable-5 adversarial pass on the diff):

• Scope of the change: paginated_public_items is called only from public_items, whose only caller is Wishlists::ProductsController#index (grep-verified). No other consumer's overflow behavior changes.
• Why :empty_page and not :last_page: the frontend consumes pagination.next for load-more; :empty_page yields next: nil and an empty items array, which terminates pagination cleanly. :last_page would re-serve duplicate items to a client that explicitly asked for a later page.
• Pagy extras: pagy/extras/overflow is already required globally in config/initializers/pagy.rb (the repo-wide default is overflow: :exception), so the per-call override needs no new require.
• Red→green proof: the new spec fails on unmodified main with Pagy::OverflowError: expected :page in 1..1; got 2 (the exact production error) and passes with the fix. All 27 pre-existing specs pass unmodified, confirming in-range pages are byte-identical.
• No P1/P2 findings.

[greptile-apps]

Greptile Summary

This PR makes out-of-range public wishlist pages return an empty result instead of an error. The main changes are:

• Uses Pagy’s empty_page overflow mode for public wishlist products.
• Adds a test for an out-of-range page request.
• Adds a QA image showing the focused presenter test results.

Confidence Score: 5/5

This looks safe to merge.

No blocking issues were found in the changed code. The overflow option follows an existing repository pattern, and the new test covers the reported out-of-range request.

T-Rex Logs

What T-Rex did

• The focused RSpec run exited with code 127 because bundler could not find the rspec command.
• The bundle check exited with code 18, confirming a Ruby version conflict with the repository's Ruby 3.4.3 requirement.
• The ruby -c syntax checks on the presenter and the focused spec reported Syntax OK, indicating no syntax errors there.
• Validation is blocked by the environment rather than an executed contradiction in the changed code.

_{Ran code and verified through T-Rex}

Important Files Changed

Filename	Overview
app/presenters/wishlist_presenter.rb	Adds a per-call overflow policy that returns an empty collection when the requested page exceeds the available pages.
spec/presenters/wishlist_presenter_spec.rb	Tests that page 2 of a one-product wishlist returns empty items and terminal pagination metadata.
qa-media/pr-wishlist-pagy-overflow-spec-results.png	Adds a QA artifact for the focused presenter test run.

_{Reviews (1): Last reviewed commit: "Return an empty page instead of 500ing o..." | Re-trigger Greptile}