fix: bound rich page rendering

src/components/page-render-budget.test.ts

@@ -0,0 +1,99 @@
+import { describe, expect, it } from 'vitest';
+
+import type { OneNoteContentBlock } from '../onenote/one/content-model.js';
+import { prepareBlocksForRendering } from './page-render-budget.js';
+
+describe('page render budget', () => {
+  it('stops reading blocks at the configured limit', () => {
+    const blocks: OneNoteContentBlock[] = Array.from(
+      { length: 200_000 },
+      (_, index) => ({
+        kind: 'unsupported',
+        id: String(index),
+        sourceJcid: index,
+        description: 'unsupported',
+      })
+    );
+
+    const plan = prepareBlocksForRendering(blocks, { maxBlocks: 3 });
+    expect(plan.blocks).toHaveLength(3);
+    expect(plan.truncated).toBe(true);
+  });
+
+  it('caps rich-text runs and characters before React sees them', () => {
+    const block: OneNoteContentBlock = {
+      kind: 'text',
+      id: 'text',
+      sourceText: 'x'.repeat(1_000),
+      text: 'x'.repeat(1_000),
+      runs: Array.from({ length: 100 }, (_, index) => ({
+        start: index * 10,
+        end: index * 10 + 10,
+        text: 'x'.repeat(10),
+        style: {},
+      })),
+      paragraphStyle: {},
+      layout: {},
+    };
+
+    const plan = prepareBlocksForRendering([block], {
+      maxTextRuns: 3,
+      maxTextCharacters: 25,
+    });
+    const projected = plan.blocks[0];
+    expect(projected?.kind).toBe('text');
+    if (projected?.kind !== 'text') throw new Error('Expected text');
+    expect(projected.runs).toHaveLength(3);
+    expect(projected.runs.map((run) => run.text).join('')).toHaveLength(25);
+    expect(plan.truncated).toBe(true);
+  });
+
+  it('caps table cells and ink points independently', () => {
+    const table: OneNoteContentBlock = {
+      kind: 'table',
+      id: 'table',
+      rows: [
+        {
+          id: 'row',
+          cells: Array.from({ length: 100 }, (_, index) => ({
+            id: String(index),
+            blocks: [],
+          })),
+        },
+      ],
+      columnWidths: [],
+      lockedColumns: [],
+      bordersVisible: true,
+      layout: {},
+    };
+    const ink: OneNoteContentBlock = {
+      kind: 'ink',
+      id: 'ink',
+      strokes: [
+        {
+          points: Array.from({ length: 100 }, (_, index) => ({
+            x: index,
+            y: index,
+          })),
+        },
+      ],
+      children: [],
+      layout: {},
+    };
+
+    const plan = prepareBlocksForRendering([table, ink], {
+      maxTableCells: 4,
+      maxInkPoints: 5,
+    });
+    const projectedTable = plan.blocks[0];
+    const projectedInk = plan.blocks[1];
+    expect(projectedTable?.kind).toBe('table');
+    expect(projectedInk?.kind).toBe('ink');
+    if (projectedTable?.kind !== 'table' || projectedInk?.kind !== 'ink') {
+      throw new Error('Expected projected table and ink');
+    }
+    expect(projectedTable.rows[0]?.cells).toHaveLength(4);
+    expect(projectedInk.strokes[0]?.points).toHaveLength(5);
+    expect(plan.truncated).toBe(true);
+  });
+});