widgetkit-code-review

What this skill does

# WidgetKit Code Review

## Quick Reference

| Issue Type | Reference |
|------------|-----------|
| TimelineProvider, entries, reload policies | [references/timeline.md](references/timeline.md) |
| Widget families, containerBackground, deep linking | [references/views.md](references/views.md) |
| AppIntentConfiguration, EntityQuery, @Parameter | [references/intents.md](references/intents.md) |
| Refresh budget, memory limits, caching | [references/performance.md](references/performance.md) |

## Review Checklist

- [ ] `placeholder(in:)` returns immediately without async work
- [ ] Timeline entries spaced at least 5 minutes apart
- [ ] `getSnapshot` checks `context.isPreview` for gallery previews
- [ ] `containerBackground(for:)` used for iOS 17+ compatibility
- [ ] `widgetURL` used for systemSmall (not Link)
- [ ] No Button views (use Link or widgetURL)
- [ ] No AsyncImage or UIViewRepresentable in widget views
- [ ] Images downsampled to widget display size (~30MB limit)
- [ ] App Groups configured for data sharing between app and widget
- [ ] EntityQuery implements `defaultResult()` for non-optional parameters
- [ ] New intent parameters handle nil for existing widgets after updates
- [ ] `reloadTimelines` called strategically (not on every data change)

## When to Load References

- TimelineProvider implementation or refresh issues -> timeline.md
- Widget sizes, Lock Screen, containerBackground -> views.md
- Configurable widgets, AppIntent migration -> intents.md
- Memory issues, caching, budget management -> performance.md

## Review Questions

1. Does the widget provide fallback entries for when system delays refresh?
2. Are Lock Screen families (accessoryCircular/Rectangular/Inline) handled appropriately?
3. Would migrating from IntentConfiguration break existing user widgets?
4. Is timeline populated with future entries or does it rely on frequent refreshes?
5. Is data cached via App Groups for widget access?

## Hard gates (before reporting)

Complete **in order** for each finding you intend to report. Do not advance until the pass condition is satisfied.

1. **Location artifact** — The finding includes `[FILE:LINE]` (or a line range) copied from the current file contents; the path resolves in this repo.
2. **Scope read** — You read the full surrounding implementation: the `TimelineProvider` (including `placeholder`, `getSnapshot`, and `getTimeline` when relevant), the `@main` `Widget` / widget bundle, or the configurable widget’s `AppIntentConfiguration` / intent types—not only a diff hunk or snippet.
3. **Platform or system claim** (only if the finding depends on refresh budget, ~30MB memory guidance, Lock Screen accessory families, iOS 17+ `containerBackground`, App Groups data sharing, or migration from `IntentConfiguration` to `AppIntentConfiguration`) — You name one concrete artifact you inspected (for example `.entitlements` / App Group id in project, `WidgetFamily` handling in source, `IPHONEOS_DEPLOYMENT_TARGET`, or the exact reference subsection you used) **or** you drop or downgrade the finding to an open question.
4. **Protocol** — Pre-report steps in [review-verification-protocol](../review-verification-protocol/SKILL.md) are satisfied for this item (no finding if they are not).

Use the issue format `[FILE:LINE] ISSUE_TITLE` for each reported finding. Hard gate 4 is the full pre-report checklist for this skill’s review type.