test: 💍 add tab switch fix test

tests/e2e/notebook.spec.ts

@@ -0,0 +1,81 @@
+// wxNotebook page-relayout e2e — regression coverage for the DOM-port fix in
+// wxwidgets/src/wasm/notebook.cpp (wxNotebook::WasmRelayoutSelectedPage).
+//
+// The "Scrolled" page wraps a wxScrolledWindow full of "Row N" labels, and the
+// app's wxEVT_NOTEBOOK_PAGE_CHANGED handler calls page->Fit() exactly like
+// KiCad's APPEARANCE_CONTROLS. Without the fix that collapses the scrolled
+// viewport and clip-paths the rows away after a tab round-trip; with it,
+// OnDomEvent re-asserts the geometry so the rows stay painted.
+import { test, expect, tryLoadApp } from './utils/fixtures';
+import { clickTab } from './utils/element-tracker';
+import type { Page } from '@playwright/test';
+
+declare global {
+  interface Window {
+    wxDomControls?: Map<number, HTMLElement>;
+  }
+}
+
+// Whether each row label is genuinely PAINTED (not merely present in the DOM).
+// A bare getBoundingClientRect is not enough: when the scrolled window collapses
+// on a tab round-trip the rows keep their layout box but are removed by an
+// ancestor's clip-path. clip-path also affects hit-testing, so we sample points
+// down each row's box and treat it as visible only if the row (or its content)
+// is actually returned by elementsFromPoint. This is what makes the collapse
+// regression fail the assertion. (Mirrors kicad/appearance.spec.ts:rowsVisible.)
+async function rowsVisible(page: Page, labels: string[]): Promise<Record<string, boolean>> {
+  return page.evaluate((wanted: string[]) => {
+    const out: Record<string, boolean> = {};
+    for (const w of wanted) out[w] = false;
+    if (!window.wxDomControls) return out;
+    const visible = (el: HTMLElement): boolean => {
+      const cs = getComputedStyle(el);
+      if (cs.display === 'none' || cs.visibility === 'hidden') return false;
+      const r = el.getBoundingClientRect();
+      if (r.width < 1 || r.height < 1) return false;
+      const cx = r.left + r.width / 2;
+      const ys = [r.top + 1, r.top + r.height / 2, r.bottom - 1];
+      return ys.some((y) => {
+        const hits = document.elementsFromPoint(cx, y);
+        return hits.some((h) => h === el || el.contains(h));
+      });
+    };
+    for (const [, el] of window.wxDomControls) {
+      const txt = el.textContent || '';
+      if (el.tagName === 'SPAN' && wanted.includes(txt) && visible(el)) out[txt] = true;
+    }
+    return out;
+  }, labels);
+}
+
+test.describe('DOM-port wxNotebook page relayout', () => {
+  test.beforeEach(async ({ page }) => {
+    await page.goto('/standalone/notebook/notebook_test.html');
+    expect(await tryLoadApp(page, 30000), 'notebook app should load').toBe(true);
+    await page.waitForTimeout(500);
+  });
+
+  test('scrolled page rows survive a tab round-trip', async ({ page, testLogger }) => {
+    // First visit to the scrolled page: rows must be painted.
+    expect(await clickTab(page, 'Scrolled'), 'switch to Scrolled').toBe(true);
+    await page.waitForTimeout(300);
+    await page.screenshot({ path: 'test-results/notebook-01-scrolled.png', fullPage: true });
+
+    let vis = await rowsVisible(page, ['Row 0', 'Row 1']);
+    expect(vis['Row 0'], 'Row 0 visible on first visit').toBe(true);
+
+    // Round-trip: away to Plain, then back to Scrolled. The PAGE_CHANGED Fit()
+    // collapses the scrolled child; WasmRelayoutSelectedPage must restore it.
+    expect(await clickTab(page, 'Plain'), 'switch to Plain').toBe(true);
+    await page.waitForTimeout(300);
+    expect(await clickTab(page, 'Scrolled'), 'switch back to Scrolled').toBe(true);
+    await page.waitForTimeout(300);
+    await page.screenshot({ path: 'test-results/notebook-02-scrolled-again.png', fullPage: true });
+
+    vis = await rowsVisible(page, ['Row 0', 'Row 1']);
+    expect(vis['Row 0'], 'Row 0 visible after tab round-trip').toBe(true);
+    expect(vis['Row 1'], 'Row 1 visible after tab round-trip').toBe(true);
+
+    expect(testLogger.errors.filter((e) => !e.includes('favicon'))).toHaveLength(0);
+  });
+});