test: add even/odd header variant tests for layout engine and per-rId layout

- Layout engine: verify oddEvenHeadersFooters drives physical-page parity
  for margin inflation (odd pages get odd-header height, even pages get
  even-header height), and that the option being unset keeps default behavior
- HeaderFooterPerRidLayout: verify even/odd header refs inherited from
  earlier sections produce per-section layout cache entries

Author: caio-pizzol

packages/layout-engine/layout-engine/src/index.test.ts

@@ -883,6 +883,92 @@ describe('layoutDocument', () => {
     expect(section2Page!.margins.top).toBeGreaterThanOrEqual(72 + tallFirst - 1);
   });
 
+  it('uses physical page number for even/odd variant selection when oddEvenHeadersFooters is enabled', () => {
+    const m = { top: 72, bottom: 72, left: 72, right: 72, header: 36, footer: 36 };
+
+    // Single section with alternateHeaders. Odd physical pages get 'odd' variant,
+    // even physical pages get 'even' variant. Each variant has a different header
+    // height so we can verify the correct one drives margin inflation.
+    const sb0: FlowBlock = {
+      kind: 'sectionBreak',
+      id: 'sb-0',
+      type: 'continuous',
+      margins: m,
+      headerRefs: { default: 'd0', even: 'e0', odd: 'o0' },
+      attrs: { isFirstSection: true, sectionIndex: 0 },
+    };
+
+    const lineHeight = 20;
+    const blocks: FlowBlock[] = [sb0, { kind: 'paragraph', id: 'p0', runs: [] }];
+    const measures: Measure[] = [
+      { kind: 'sectionBreak' },
+      makeMeasure(Array(80).fill(lineHeight)), // enough content for multiple pages
+    ];
+
+    const evenHeight = 120;
+    const oddHeight = 80;
+    const sectionMetadata: SectionMetadata[] = [
+      { sectionIndex: 0, headerRefs: { default: 'd0', even: 'e0', odd: 'o0' } },
+    ];
+
+    const layout = layoutDocument(blocks, measures, {
+      pageSize: { w: 612, h: 792 },
+      margins: m,
+      sectionMetadata,
+      oddEvenHeadersFooters: true,
+      headerContentHeightsByRId: new Map([
+        ['e0', evenHeight],
+        ['o0', oddHeight],
+      ]),
+    });
+
+    expect(layout.pages.length).toBeGreaterThanOrEqual(2);
+
+    // Page 1 (physical 1, odd): odd variant → margin inflated by oddHeight
+    const page1 = layout.pages[0];
+    expect(page1.margins.top).toBeGreaterThanOrEqual(36 + oddHeight - 1);
+
+    // Page 2 (physical 2, even): even variant → margin inflated by evenHeight
+    const page2 = layout.pages[1];
+    expect(page2.margins.top).toBeGreaterThanOrEqual(36 + evenHeight - 1);
+    // Even margin should be larger than odd margin since evenHeight > oddHeight
+    expect(page2.margins.top).toBeGreaterThan(page1.margins.top);
+  });
+
+  it('does not use even/odd variants when oddEvenHeadersFooters is not set', () => {
+    const m = { top: 72, bottom: 72, left: 72, right: 72, header: 36, footer: 36 };
+    const sb0: FlowBlock = {
+      kind: 'sectionBreak',
+      id: 'sb-0',
+      type: 'continuous',
+      margins: m,
+      headerRefs: { default: 'd0', even: 'e0' },
+      attrs: { isFirstSection: true, sectionIndex: 0 },
+    };
+
+    const lineHeight = 20;
+    const blocks: FlowBlock[] = [sb0, { kind: 'paragraph', id: 'p0', runs: [] }];
+    const measures: Measure[] = [{ kind: 'sectionBreak' }, makeMeasure(Array(80).fill(lineHeight))];
+
+    const tallEven = 200;
+    const layout = layoutDocument(blocks, measures, {
+      pageSize: { w: 612, h: 792 },
+      margins: m,
+      sectionMetadata: [{ sectionIndex: 0, headerRefs: { default: 'd0', even: 'e0' } }],
+      // oddEvenHeadersFooters NOT set
+      headerContentHeightsByRId: new Map([
+        ['e0', tallEven],
+        ['d0', 10],
+      ]),
+    });
+
+    // Without oddEvenHeadersFooters, all pages use 'default' variant —
+    // margins should NOT be inflated by the even header height
+    for (const page of layout.pages) {
+      expect(page.margins.top).toBeLessThan(36 + tallEven);
+    }
+  });
+
   it('applies section break margins to subsequent pages', () => {
     const sectionBreakBlock: FlowBlock = {
       kind: 'sectionBreak',

packages/super-editor/src/editors/v1/core/header-footer/HeaderFooterPerRidLayout.test.ts

@@ -129,4 +129,75 @@ describe('layoutPerRIdHeaderFooters', () => {
     expect(deps.headerLayoutsByRId.has('rId-header-first')).toBe(true);
     expect(deps.headerLayoutsByRId.has('rId-header-orphan')).toBe(false);
   });
+
+  it('lays out even/odd header refs inherited from earlier sections', async () => {
+    const deps = {
+      headerLayoutsByRId: new Map(),
+      footerLayoutsByRId: new Map(),
+    };
+
+    const layout: Layout = {
+      pageSize: { w: 612, h: 792 },
+      pages: [
+        { number: 1, fragments: [], sectionIndex: 0 },
+        { number: 2, fragments: [], sectionIndex: 0 },
+        { number: 3, fragments: [], sectionIndex: 1 },
+      ],
+    };
+
+    const sectionMetadata: SectionMetadata[] = [
+      {
+        sectionIndex: 0,
+        pageSize: { w: 612, h: 792 },
+        margins: { top: 72, right: 72, bottom: 72, left: 72, header: 36 },
+        headerRefs: {
+          default: 'rId-default',
+          even: 'rId-even',
+          odd: 'rId-odd',
+        },
+      },
+      {
+        sectionIndex: 1,
+        pageSize: { w: 612, h: 792 },
+        margins: { top: 72, right: 72, bottom: 72, left: 72, header: 36 },
+        headerRefs: {
+          default: 'rId-default-s1',
+          // even and odd NOT defined — should be inherited from section 0
+        },
+      },
+    ];
+
+    await layoutPerRIdHeaderFooters(
+      {
+        headerBlocksByRId: new Map([
+          ['rId-default', [makeParagraph('h-default', 'Default')]],
+          ['rId-even', [makeParagraph('h-even', 'Even header')]],
+          ['rId-odd', [makeParagraph('h-odd', 'Odd header')]],
+          ['rId-default-s1', [makeParagraph('h-default-s1', 'Section 1 default')]],
+        ]),
+        footerBlocksByRId: new Map(),
+        constraints: {
+          width: 468,
+          height: 648,
+          pageWidth: 612,
+          pageHeight: 792,
+          margins: { left: 72, right: 72, top: 72, bottom: 72, header: 36 },
+          overflowBaseHeight: 36,
+        },
+      },
+      layout,
+      sectionMetadata,
+      deps,
+    );
+
+    // Section 0 should have default, even, and odd layouts
+    expect(deps.headerLayoutsByRId.has('rId-default::s0')).toBe(true);
+    expect(deps.headerLayoutsByRId.has('rId-even::s0')).toBe(true);
+    expect(deps.headerLayoutsByRId.has('rId-odd::s0')).toBe(true);
+
+    // Section 1 should have its own default, plus inherited even and odd from section 0
+    expect(deps.headerLayoutsByRId.has('rId-default-s1::s1')).toBe(true);
+    expect(deps.headerLayoutsByRId.has('rId-even::s1')).toBe(true);
+    expect(deps.headerLayoutsByRId.has('rId-odd::s1')).toBe(true);
+  });
 });