fix(narration): match atWord anchors outside ASCII

src/narration.ts

@@ -647,6 +647,9 @@ export class NarrationTimeline {
     if (!words?.length) return null;
 
     const normalized = normalizeWord(target);
+    // Pure punctuation strips to nothing on both sides, so without this the
+    // first such token in the scene matches and the caller gets a wrong time.
+    if (!normalized) return null;
     for (const w of words) {
       if (normalizeWord(w.text) !== normalized) continue;
       const elapsedInSceneMs = (Date.now() - this.startTime) - markMs;
@@ -657,7 +660,14 @@ export class NarrationTimeline {
   }
 }
 
-const normalizeWord = (s: string): string => s.toLowerCase().replace(/[^\w']/g, '');
+/**
+ * `\w` is ASCII-only and strips a non-Latin token to '', so every such
+ * token compares equal. `\p{M}` is needed too: combining marks carry the
+ * sound in Devanagari, Thai and Arabic. NFC first, so decomposed equals
+ * precomposed.
+ */
+const normalizeWord = (s: string): string =>
+  s.normalize('NFC').toLowerCase().replace(/[^\p{L}\p{M}\p{N}']/gu, '');
 
 export interface WordTiming {
   text: string;

tests/narration-atword.test.ts

@@ -0,0 +1,105 @@
+import { describe, it, expect, beforeAll, afterAll } from 'vitest';
+import { mkdtempSync, writeFileSync, rmSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { NarrationTimeline } from '../src/narration.js';
+
+const WORDS = (...pairs: Array<[string, number]>) =>
+  pairs.map(([text, start]) => ({ text, start, end: start + 0.4 }));
+
+/**
+ * The transcript is cached per process on first read, so every case here shares
+ * one file with a scene per language.
+ */
+const TRANSCRIPT = {
+  version: 1,
+  model: 'test',
+  scenes: {
+    ru: WORDS(['Две', 1], ['заявки,', 2], ['одобрены.', 3]),
+    zh: WORDS(['两', 1], ['个', 2], ['申请', 3]),
+    hi: WORDS(['दो', 1], ['अनुरोध,', 2], ['स्वीकृत।', 3]),
+    de: WORDS(['Zwei', 1], ['Anträge,', 2], ['genehmigt.', 3]),
+    en: WORDS(['Two', 1], ['requests,', 2], ['approved.', 3]),
+
+    // Pairs differing only by a combining mark: without \p{M} each collapses
+    // onto one spelling and the anchor lands on whichever came first.
+    hiMarks: WORDS(['कल', 1], ['है', 2], ['काल', 3]),
+    thMarks: WORDS(['ไม้', 1], ['คือ', 2], ['ไม่', 3]),
+
+    punct: WORDS(['...', 1], ['hello', 2], ['world', 3]),
+  },
+};
+
+let dir: string;
+
+beforeAll(() => {
+  dir = mkdtempSync(join(tmpdir(), 'argo-atword-'));
+  const path = join(dir, 'transcript.json');
+  writeFileSync(path, JSON.stringify(TRANSCRIPT), 'utf-8');
+  process.env.ARGO_TRANSCRIPT_PATH = path;
+});
+
+afterAll(() => {
+  delete process.env.ARGO_TRANSCRIPT_PATH;
+  rmSync(dir, { recursive: true, force: true });
+});
+
+/** A timeline sitting at the very start of `scene`. */
+function atStartOf(scene: string): NarrationTimeline {
+  const timeline = new NarrationTimeline();
+  timeline.start();
+  timeline.mark(scene);
+  return timeline;
+}
+
+describe('atWord across scripts', () => {
+  it.each([
+    ['ru', 'одобрены'],
+    ['zh', '申请'],
+    ['hi', 'स्वीकृत'],
+    ['de', 'genehmigt'],
+    ['en', 'approved'],
+  ])('finds the third word in %s and not the first', (scene, anchor) => {
+    const ms = atStartOf(scene).atWord(scene, anchor);
+    expect(ms).toBeGreaterThan(2500);
+    expect(ms).toBeLessThanOrEqual(3000);
+  });
+
+  it('keeps a diacritic significant instead of stripping it', () => {
+    expect(atStartOf('de').atWord('de', 'Anträge')).toBeGreaterThan(1500);
+    expect(atStartOf('de').atWord('de', 'antrge')).toBeNull();
+  });
+
+  it('still ignores case and trailing punctuation', () => {
+    expect(atStartOf('en').atWord('en', 'REQUESTS')).toBeGreaterThan(1500);
+    expect(atStartOf('ru').atWord('ru', 'заявки')).toBeGreaterThan(1500);
+  });
+
+  it('returns null for a word the scene does not contain', () => {
+    expect(atStartOf('ru').atWord('ru', 'отклонены')).toBeNull();
+    expect(atStartOf('zh').atWord('zh', '批准')).toBeNull();
+  });
+});
+
+describe('atWord and combining marks', () => {
+  it.each([
+    ['hiMarks', 'काल', 'कल'],
+    ['thMarks', 'ไม่', 'ไม้'],
+  ])('%s: anchors on %s rather than the mark-stripped %s', (scene, anchor) => {
+    const ms = atStartOf(scene).atWord(scene, anchor);
+    expect(ms).toBeGreaterThan(2500);
+    expect(ms).toBeLessThanOrEqual(3000);
+  });
+
+  it('matches a decomposed anchor against a precomposed transcript', () => {
+    // A null here is indistinguishable from "the word is already spoken".
+    expect(atStartOf('de').atWord('de', 'Anträge'.normalize('NFD'))).toBeGreaterThan(1500);
+  });
+
+  it('refuses an anchor that strips to nothing', () => {
+    // Anchor and first token both normalise to '', so unguarded they match.
+    expect(atStartOf('punct').atWord('punct', '...')).toBeNull();
+    expect(atStartOf('punct').atWord('punct', '?!')).toBeNull();
+    expect(atStartOf('punct').atWord('punct', 'world')).toBeGreaterThan(2500);
+  });
+});