First
Second
`); const iterator = await ParagraphIterator.createAsync(doc, 1000); expect(iterator.length).toBe(2); expect(iterator.first()?.toString()).toContain('First'); expect(iterator.next()?.toString()).toContain('Second'); }); it('keeps paragraphs with non-text content', async () => { const doc = createDoc(`Intro
Outro
`); const iterator = await ParagraphIterator.createAsync(doc, 1000); expect(iterator.length).toBe(3); iterator.first(); expect(iterator.current()?.toString()).toContain('Intro'); const imageRange = iterator.next(); const fragment = imageRange?.cloneContents(); expect(fragment?.querySelector('img')).not.toBeNull(); expect(iterator.next()?.toString()).toContain('Outro'); }); }); describe('ParagraphIterator.findIndexByRange', () => { // Five compact, single-text-node blocks so indices map 1:1 to paragraphs. const buildIterator = async () => { const doc = createDoc( `Zero
One
Two
Three
Four
`, ); const iterator = await ParagraphIterator.createAsync(doc, 1000); return { doc, iterator }; }; // Builds a collapsed Range at `offset` inside the text node of paragraph `id`. const pointInside = (doc: Document, id: string, offset = 0): Range => { const el = doc.getElementById(id)!; const textNode = el.firstChild!; const range = doc.createRange(); range.setStart(textNode, offset); range.setEnd(textNode, offset); return range; }; it('returns the index of the block that contains the target start (containment)', async () => { const { doc, iterator } = await buildIterator(); // A point inside block 2's text must resolve to 2 (not 1 or 3). const target = pointInside(doc, 'b2', 1); expect(iterator.findIndexByRange(target)).toBe(2); }); it('returns -1 (not 0) when the target is after the last block', async () => { const { doc, iterator } = await buildIterator(); // Append a node AFTER the iterator is built so it belongs to no block and // sits in document order past the last block's end. const trailing = doc.createElement('span'); trailing.textContent = 'trailing'; doc.body.appendChild(trailing); const range = doc.createRange(); range.setStart(trailing.firstChild!, 0); range.collapse(true); expect(iterator.findIndexByRange(range)).toBe(-1); }); it('returns the nearest following block when the target falls in a gap', async () => { const { doc, iterator } = await buildIterator(); // Insert a node between block 2 and block 3 AFTER the iterator is built so // it sits in a genuine gap that no block range covers. const gap = doc.createElement('span'); gap.textContent = 'gap'; doc.body.insertBefore(gap, doc.getElementById('b3')); const range = doc.createRange(); range.setStart(gap.firstChild!, 0); range.collapse(true); // No block contains the gap point; the nearest following block is index 3. expect(iterator.findIndexByRange(range)).toBe(3); }); it('returns -1 when there are no blocks', async () => { const doc = createDoc(``); const iterator = await ParagraphIterator.createAsync(doc, 1000); expect(iterator.length).toBe(0); const range = doc.createRange(); range.setStart(doc.body, 0); range.collapse(true); expect(iterator.findIndexByRange(range)).toBe(-1); }); it('resolves correctly with a correct hint (fast path)', async () => { const { doc, iterator } = await buildIterator(); const target = pointInside(doc, 'b3', 0); expect(iterator.findIndexByRange(target, 3)).toBe(3); }); it('resolves correctly with a stale hint (binary-search fallback)', async () => { const { doc, iterator } = await buildIterator(); const target = pointInside(doc, 'b1', 0); // Hint points far away (block 4); must still resolve to 1. expect(iterator.findIndexByRange(target, 4)).toBe(1); }); });