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6 changes: 2 additions & 4 deletions README.md
Original file line number Diff line number Diff line change
Expand Up @@ -49,10 +49,8 @@ To install this Skill for your personal use in Claude Code:
/plugin install swiftui-expert@swiftui-expert-skill
```

### Option C: Cursor plugin (coming soon)
This repository is now packaged for Cursor plugin submission, but the marketplace listing is not live yet.

Once approved, you'll be able to install it from the Cursor Marketplace.
### Option C: Cursor plugin
This repository is packaged as a Cursor plugin. See [Cursor plugins documentation](https://cursor.com/docs/plugins) for installation instructions.

#### Project Configuration
To automatically provide this Skill to everyone working in a repository, configure the repository's `.claude/settings.json`:
Expand Down
61 changes: 1 addition & 60 deletions swiftui-expert-skill/SKILL.md
Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
---
name: swiftui-expert-skill
description: Write, review, or improve SwiftUI code following best practices for state management, view composition, performance, macOS-specific APIs, and iOS 26+ Liquid Glass adoption. Use when building new SwiftUI features, refactoring existing views, reviewing code quality, or adopting modern SwiftUI patterns. Also triggers whenever an Xcode Instruments `.trace` file is referenced (to analyse it) or the user asks to **record** a new trace — attach to a running app, launch one fresh, or capture a manually-stopped session with the bundled `record_trace.py`. A target SwiftUI source file is optional; if provided it grounds recommendations in specific lines, but a trace alone is enough to diagnose hangs, hitches, CPU hotspots, and high-severity SwiftUI updates.
description: Write, review, or improve SwiftUI code following best practices for state management, view composition, performance, macOS-specific APIs, and iOS 26+ Liquid Glass adoption. Use when building new SwiftUI features, refactoring existing views, reviewing code quality, or adopting modern SwiftUI patterns.
---

# SwiftUI Expert Skill
Expand Down Expand Up @@ -38,55 +38,6 @@ description: Write, review, or improve SwiftUI code following best practices for
- Use `Button` for all tappable elements; add accessibility grouping and labels
- Gate version-specific APIs with `#available` and provide fallbacks

### Record a new Instruments trace
Trigger when the user asks to "record a trace", "profile the app", "capture a session", etc. Full reference: `references/trace-recording.md`.

1. **Confirm target** — attach to a running app, launch an app, or record all processes? If the user didn't say, ask. List connected devices when useful:
```bash
python3 "${SKILL_DIR}/scripts/record_trace.py" --list-devices
```
2. **Pick a template based on target kind** — the `SwiftUI` template populates the SwiftUI lane on any **real device**: a physical iOS/iPadOS device **or the host Mac**. The only exception is the **iOS Simulator**, where the SwiftUI lane comes back empty — switch to `--template "Time Profiler"` in that case (still gives Time Profiler + Hangs + Animation Hitches). Always check `--list-devices`: `simulators` kind → `Time Profiler`; `devices` kind (real devices and the host Mac) → default `SwiftUI`. Full decision table in `references/trace-recording.md`.
3. **Start the recording**. For agent-driven sessions where the user says "I'll tell you when I'm done", start in the background and use a stop-file:
```bash
python3 "${SKILL_DIR}/scripts/record_trace.py" \
--device "<name|udid>" --attach "<AppName>" \
--stop-file /tmp/stop-trace --output ~/Desktop/session.trace
```
For interactive sessions, just tell the user to press Ctrl+C when done.
4. **Signal stop** — when the user says they've finished exercising the app, `touch /tmp/stop-trace`. The script cleanly SIGINTs xctrace and waits up to 60s for finalisation.
5. **Analyse** the resulting trace (flow into the "Trace-driven improvement" workflow below).

### Trace-driven improvement (Instruments `.trace` provided)
Trigger whenever the user's request references a `.trace` file. A target SwiftUI source file is **optional** — if given, cite specific lines; if not, recommend where to look based on view names and symbols the trace already reveals.

Full reference: `references/trace-analysis.md`. Summary of the composition pattern:

1. **Scope the analysis.** Ask yourself: does the user want the whole trace, or a slice?
- "focus on X / after X / between X and Y / during X" → **resolve to a window first** (see step 2).
- No scoping cue → analyse the whole trace.
2. **Resolve a window (only if the user scoped).** The parser exposes two discovery modes:
```bash
# Find a log that marks the start/end of the region of interest:
python3 "${SKILL_DIR}/scripts/analyze_trace.py" --trace <path> \
--list-logs --log-message-contains "loaded feed" --log-limit 5
# Or list os_signpost intervals (paired begin/end), filterable by name:
python3 "${SKILL_DIR}/scripts/analyze_trace.py" --trace <path> \
--list-signposts --signpost-name-contains "ImageDecode"
```
Both modes accept `--window START_MS:END_MS` to scope discovery. Pick the `time_ms` (for logs) or `start_ms`/`end_ms` (for signposts) that match the user's description. Build a window like `--window 10400:11700`.
3. **Run the main analysis** (with or without `--window`):
```bash
python3 "${SKILL_DIR}/scripts/analyze_trace.py" --trace <path> \
--json-only --top 10 [--window START_MS:END_MS]
```
4. **Interpret with `references/trace-analysis.md`** — key diagnostics:
- `main_running_coverage_pct` inside each correlation (<25% = blocked; ≥75% = CPU-bound).
- `swiftui-causes.top_sources` reveals *why* updates keep happening — high-edge-count sources like `UserDefaultObserver.send()` or wide `EnvironmentWriter` entries are structural invalidation bugs. Fixing one often collapses many downstream hot views.
5. **When a specific view shows as expensive, ask who's invalidating it.** Use `--fanin-for "<view name>"` to get the ranked list of source nodes driving the updates.
6. **Optionally ground in source.** If the user pointed at a file, read it and match view names / user-code symbols against identifiers there. If not, recommend which files to open based on the view names SwiftUI reported.
7. **Return a prioritised plan.** Cite evidence (coverage %, hot symbol, overlapping view, log timestamp, cause-graph edges) and route each recommendation to a Topic Router reference.
8. Only edit code if the user asked for edits.

### Topic Router

Consult the reference file for each topic relevant to the current task:
Expand All @@ -100,7 +51,6 @@ Consult the reference file for each topic relevant to the current task:
| Layout | `references/layout-best-practices.md` |
| Sheets and navigation | `references/sheet-navigation-patterns.md` |
| ScrollView | `references/scroll-patterns.md` |
| Focus management | `references/focus-patterns.md` |
| Animations (basics) | `references/animation-basics.md` |
| Animations (transitions) | `references/animation-transitions.md` |
| Animations (advanced) | `references/animation-advanced.md` |
Expand All @@ -112,10 +62,7 @@ Consult the reference file for each topic relevant to the current task:
| macOS scenes | `references/macos-scenes.md` |
| macOS window styling | `references/macos-window-styling.md` |
| macOS views | `references/macos-views.md` |
| Text patterns | `references/text-patterns.md` |
| Deprecated API lookup | `references/latest-apis.md` |
| Instruments trace analysis | `references/trace-analysis.md` |
| Instruments trace recording | `references/trace-recording.md` |

## Correctness Checklist

Expand All @@ -129,8 +76,6 @@ These are hard rules -- violations are always bugs:
- [ ] `ForEach` uses stable identity (never `.indices` for dynamic content)
- [ ] Constant number of views per `ForEach` element
- [ ] `.animation(_:value:)` always includes the `value` parameter
- [ ] `@FocusState` properties are `private`
- [ ] No redundant `@FocusState` writes inside tap gesture handlers on `.focusable()` views
- [ ] iOS 26+ APIs gated with `#available` and fallback provided
- [ ] `import Charts` present in files using chart types

Expand All @@ -150,12 +95,8 @@ These are hard rules -- violations are always bugs:
- `references/charts-accessibility.md` -- Charts VoiceOver, Audio Graph, fallback strategies
- `references/sheet-navigation-patterns.md` -- Sheets, NavigationSplitView, Inspector
- `references/scroll-patterns.md` -- ScrollViewReader, programmatic scrolling
- `references/focus-patterns.md` -- Focus state, focusable views, focused values, default focus, common pitfalls
- `references/image-optimization.md` -- AsyncImage, downsampling, caching
- `references/liquid-glass.md` -- iOS 26+ Liquid Glass effects and fallback patterns
- `references/macos-scenes.md` -- Settings, MenuBarExtra, WindowGroup, multi-window
- `references/macos-window-styling.md` -- Toolbar styles, window sizing, Commands
- `references/macos-views.md` -- HSplitView, Table, PasteButton, AppKit interop
- `references/text-patterns.md` -- Text initializer selection, verbatim vs localized
- `references/trace-analysis.md` -- Parse Instruments `.trace` files via `scripts/analyze_trace.py`; interpret main-thread coverage, high-severity SwiftUI updates, hitch narratives, and map findings back to source files
- `references/trace-recording.md` -- Record a new trace via `scripts/record_trace.py`: attach to a running app, launch one fresh, or capture a manually-stopped session; supports stop-file for agent-driven flows