jackwener__opencli/clis/youtube/transcript-group.test.ts

import { describe, it, expect } from 'vitest';
import { groupTranscriptSegments, formatGroupedTranscript } from './transcript-group.js';

describe('groupTranscriptSegments', () => {
  it('groups segments by sentence boundaries', () => {
    const segments = [
      { start: 0, text: 'Hello there.' },
      { start: 2, text: 'How are you doing today?' },
      { start: 5, text: 'I am' },
      { start: 6, text: 'doing well.' },
    ];
    const result = groupTranscriptSegments(segments);
    expect(result).toHaveLength(3);
    expect(result[0].text).toBe('Hello there.');
    expect(result[1].text).toBe('How are you doing today?');
    expect(result[2].text).toBe('I am doing well.');
  });

  it('flushes on large time gaps', () => {
    const segments = [
      { start: 0, text: 'First part' },
      { start: 2, text: 'still first' },
      { start: 25, text: 'second part after gap' },
    ];
    const result = groupTranscriptSegments(segments);
    expect(result).toHaveLength(2);
    expect(result[0].text).toBe('First part still first');
    expect(result[1].text).toBe('second part after gap');
  });

  it('respects 30s max group span for unpunctuated text', () => {
    // Simulate CJK captions without punctuation
    const segments = Array.from({ length: 20 }, (_, i) => ({
      start: i * 2,
      text: `segment${i}`,
    }));
    const result = groupTranscriptSegments(segments);
    // 20 segments * 2s = 40s total, should be split into at least 2 groups
    expect(result.length).toBeGreaterThanOrEqual(2);
    // No single group should span more than ~30s
    for (const g of result) {
      const words = g.text.split(' ');
      // With 2s per segment and 30s max, each group should have at most ~16 segments
      expect(words.length).toBeLessThanOrEqual(16);
    }
  });

  it('detects speaker changes via >> markers', () => {
    const segments = [
      { start: 0, text: '>> How are you?' },
      { start: 3, text: '>> I am fine.' },
    ];
    const result = groupTranscriptSegments(segments);
    expect(result.some(g => g.speakerChange)).toBe(true);
    expect(result.some(g => g.speaker !== undefined)).toBe(true);
  });

  it('recognizes CJK sentence-ending punctuation', () => {
    const segments = [
      { start: 0, text: '你好世界。' },
      { start: 2, text: '这是测试' },
      { start: 4, text: '内容。' },
    ];
    const result = groupTranscriptSegments(segments);
    expect(result).toHaveLength(2);
    expect(result[0].text).toBe('你好世界。');
    expect(result[1].text).toBe('这是测试 内容。');
  });

  it('returns empty array for empty input', () => {
    expect(groupTranscriptSegments([])).toEqual([]);
  });
});

describe('formatGroupedTranscript', () => {
  it('formats timestamps correctly', () => {
    const segments = [
      { start: 65, text: 'One minute five.', speakerChange: false },
      { start: 3661, text: 'One hour one minute.', speakerChange: false },
    ];
    const { rows } = formatGroupedTranscript(segments);
    expect(rows[0].timestamp).toBe('1:05');
    expect(rows[1].timestamp).toBe('1:01:01');
  });

  it('inserts chapter headings at correct positions', () => {
    const segments = [
      { start: 0, text: 'Intro text.', speakerChange: false },
      { start: 60, text: 'Chapter content.', speakerChange: false },
    ];
    const chapters = [{ title: 'Introduction', start: 0 }, { title: 'Main', start: 50 }];
    const { rows } = formatGroupedTranscript(segments, chapters);
    expect(rows[0].text).toBe('[Chapter] Introduction');
    expect(rows[1].text).toBe('Intro text.');
    expect(rows[2].text).toBe('[Chapter] Main');
    expect(rows[3].text).toBe('Chapter content.');
  });

  it('labels speakers', () => {
    const segments = [
      { start: 0, text: 'Hello.', speakerChange: true, speaker: 0 },
      { start: 5, text: 'Hi there.', speakerChange: true, speaker: 1 },
    ];
    const { rows } = formatGroupedTranscript(segments);
    expect(rows[0].speaker).toBe('Speaker 1');
    expect(rows[1].speaker).toBe('Speaker 2');
  });
});