perf(tokenizer): single-pass Yomitan scan with cross-line caching and prefetch fixes (#185)

src/main/character-dictionary-runtime/name-candidates.test.ts

@@ -0,0 +1,163 @@
+import assert from 'node:assert/strict';
+import * as fs from 'fs';
+import * as os from 'os';
+import * as path from 'path';
+import test from 'node:test';
+import { CHARACTER_DICTIONARY_FORMAT_VERSION } from './constants';
+import { createCharacterNameCandidateLookup } from './name-candidates';
+
+function writeSnapshot(outputDir: string, mediaId: number, entries: Array<[string, string]>): void {
+  const snapshotsDir = path.join(outputDir, 'snapshots');
+  fs.mkdirSync(snapshotsDir, { recursive: true });
+  fs.writeFileSync(
+    path.join(snapshotsDir, `anilist-${mediaId}.json`),
+    JSON.stringify({
+      formatVersion: CHARACTER_DICTIONARY_FORMAT_VERSION,
+      mediaId,
+      mediaTitle: `title-${mediaId}`,
+      entryCount: entries.length,
+      updatedAt: 1,
+      termEntries: entries.map(([term, reading]) => [
+        term,
+        reading,
+        'name main',
+        '',
+        100,
+        [],
+        0,
+        '',
+      ]),
+      images: [],
+    }),
+  );
+}
+
+function withTempDir<T>(run: (dir: string) => T): T {
+  const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'subminer-name-candidates-'));
+  try {
+    return run(dir);
+  } finally {
+    fs.rmSync(dir, { recursive: true, force: true });
+  }
+}
+
+test('collects terms and readings for the current media', () => {
+  withTempDir((dir) => {
+    writeSnapshot(dir, 1, [
+      ['ミナト', 'みなと'],
+      ['湊', 'みなと'],
+    ]);
+    writeSnapshot(dir, 2, [['カズマ', 'かずま']]);
+
+    const lookup = createCharacterNameCandidateLookup({
+      outputDir: dir,
+      getCurrentMediaId: () => 1,
+    });
+    const candidates = lookup.get();
+
+    assert.ok(candidates);
+    assert.deepEqual([...candidates.forms].sort(), ['みなと', 'ミナト', '湊'].sort());
+    // Deduplicated: both entries share the みなと reading.
+    assert.equal(candidates.forms.length, 3);
+  });
+});
+
+test('returns null without a media scope so the scanner stays exhaustive', () => {
+  withTempDir((dir) => {
+    writeSnapshot(dir, 1, [['ミナト', 'みなと']]);
+
+    const lookup = createCharacterNameCandidateLookup({
+      outputDir: dir,
+      getCurrentMediaId: () => null,
+    });
+
+    assert.equal(lookup.get(), null);
+  });
+});
+
+test('returns null for a media with no cached snapshot', () => {
+  withTempDir((dir) => {
+    writeSnapshot(dir, 1, [['ミナト', 'みなと']]);
+
+    const lookup = createCharacterNameCandidateLookup({
+      outputDir: dir,
+      getCurrentMediaId: () => 999,
+    });
+
+    assert.equal(lookup.get(), null);
+  });
+});
+
+test('key changes when the snapshot content changes', () => {
+  withTempDir((dir) => {
+    writeSnapshot(dir, 1, [['ミナト', 'みなと']]);
+    const lookup = createCharacterNameCandidateLookup({
+      outputDir: dir,
+      getCurrentMediaId: () => 1,
+    });
+    const first = lookup.get();
+
+    writeSnapshot(dir, 1, [
+      ['ミナト', 'みなと'],
+      ['アクア', 'あくあ'],
+    ]);
+    lookup.invalidate();
+    const second = lookup.get();
+
+    assert.ok(first && second);
+    assert.notEqual(first.key, second.key);
+    assert.equal(second.forms.length, 4);
+  });
+});
+
+// The lookup runs once per subtitle line, so it must not stat the snapshot
+// directory every call. Asserted behaviorally: an unannounced on-disk change is
+// invisible until the recheck interval elapses, which can only be true if the
+// filesystem is not consulted per lookup.
+test('does not re-read the snapshot directory on every lookup', () => {
+  withTempDir((dir) => {
+    writeSnapshot(dir, 1, [['ミナト', 'みなと']]);
+    let nowMs = 1_000_000;
+    const lookup = createCharacterNameCandidateLookup({
+      outputDir: dir,
+      getCurrentMediaId: () => 1,
+      now: () => nowMs,
+    });
+
+    assert.equal(lookup.get()?.forms.length, 2);
+
+    writeSnapshot(dir, 1, [
+      ['ミナト', 'みなと'],
+      ['アクア', 'あくあ'],
+    ]);
+
+    nowMs += 1000;
+    assert.equal(lookup.get()?.forms.length, 2, 'expected the cached list within the interval');
+
+    nowMs += 10_000;
+    assert.equal(lookup.get()?.forms.length, 4, 'expected a refresh past the interval');
+  });
+});
+
+test('invalidate picks up a snapshot change immediately', () => {
+  withTempDir((dir) => {
+    writeSnapshot(dir, 1, [['ミナト', 'みなと']]);
+    let nowMs = 1_000_000;
+    const lookup = createCharacterNameCandidateLookup({
+      outputDir: dir,
+      getCurrentMediaId: () => 1,
+      now: () => nowMs,
+    });
+
+    assert.equal(lookup.get()?.forms.length, 2);
+
+    writeSnapshot(dir, 1, [
+      ['ミナト', 'みなと'],
+      ['アクア', 'あくあ'],
+    ]);
+    nowMs += 1;
+    lookup.invalidate();
+
+    assert.equal(lookup.get()?.forms.length, 4);
+  });
+});