ui-check

name	ui-check
description	Gate the RING-5 web layer — the Page→Controller→Component pattern (no presenter), namespaced UI state, dual-engine rendering, and the UI test layers. Use when reviewing/verifying anything under src/web/, Streamlit pages/components, or UI state.

UI check (the presentation-layer gate)

Layer C (src/web/ + app.py) is Streamlit + Plotly/Matplotlib. This gate verifies the UI conventions and runs the right test layers. For writing UI tests, use the e2e-streamlit-testing skill; this skill is the conformance gate.

Conventions to verify

• Page → Controller → Component (PCC). There is NO presenter layer (it was removed). Pages (src/web/pages/) wire controllers (src/web/controllers/plot/: creation/pipeline/render) to self-contained components (src/web/components/). A new "presenter" module is a regression.
• UI state is namespaced & typed via src/web/state/ui_state_manager.py::UIStateManager — keys are plot.{id}.*, manager.*, nav.*, export.* (built by WidgetKeyBuilder). Raw ad-hoc st.session_state["auto_42"] strings are the anti-pattern.
• Per-plot widget keys are unique: f"{prefix}_{field}_{plot_id}" — shared keys across plots cause cross-talk.
• Dual engine: rendering goes through FigureConfig → connectors; the engine is switched by the ring5_engine_mode session key (EngineManager). Default palette is wong. The plot class never calls go.*/plt.* (see plot-type-check).
• Settings ownership (don't misfile a control): tick marks / tick pad / grid dash → Axes pill; Typography = font sizes/colors only; Y-axis title standoff & vshift → Axes Y-Left pill.
• Components are self-contained widgets — no business logic; that belongs in a service behind the facade.

Run the tests (no browser → browser)

./python_venv/bin/pytest tests/ui tests/ui_logic tests/ui_unit -q   # AppTest + controllers + mocked-st
make test-visual                                                    # Playwright, spins Streamlit on :8502

• tests/ui/ — Streamlit AppTest (no browser). tests/ui_logic/ — controllers/UI logic. tests/ui_unit/ — components with a mocked st.
• Reuse columns_side_effect from the root tests/conftest.py for mocking st.columns — don't redefine it.
• tests/e2e/ + tests/visual/ are Playwright (requires_browser), Page Object Model, data-testid selectors. Mind the segmented-control toggle & fragment-rerun gotchas documented in e2e-streamlit-testing.

Quick smells

grep -rni "presenter" src/web/ --include=*.py            # should be empty (layer removed)
grep -rn "st.session_state\[" src/web/ --include=*.py     # prefer UIStateManager/WidgetKeyBuilder

Keep this skill sharp

Canon, not history — edit in place when the UI conventions move:

• Namespaces, the engine key, and settings-ownership above mirror ui_state_manager.py, engine_manager.py, and the settings pills. If those change, update this list.
• New UI footgun found in review? Add it here (and to e2e-streamlit-testing if it's test-mechanics); durable facts → a memory.

Verify after

make arch-check && ./python_venv/bin/pytest tests/ui tests/ui_logic tests/ui_unit -q