build(ts): enable noUncheckedIndexedAccess and isolatedModules

src/core/services/anilist/anilist-updater.ts

@@ -168,7 +168,7 @@ function pickBestSearchResult(
     return titles.includes(normalizedTarget);
   });
 
-  const selected = exact ?? candidates[0];
+  const selected = exact ?? candidates[0]!;
   const selectedTitle =
     selected.title?.english || selected.title?.romaji || selected.title?.native || title;
   return { id: selected.id, title: selectedTitle };

src/core/services/anki-jimaku.test.ts

@@ -129,7 +129,7 @@ test('refreshKnownWords throws when integration is unavailable', async () => {
 
   await assert.rejects(
     async () => {
-      await registered.refreshKnownWords();
+      await registered.refreshKnownWords!();
     },
     { message: 'AnkiConnect integration not enabled' },
   );
@@ -144,7 +144,7 @@ test('refreshKnownWords delegates to integration', async () => {
     },
   };
 
-  await registered.refreshKnownWords();
+  await registered.refreshKnownWords!();
 
   assert.equal(refreshed, 1);
 });
@@ -158,7 +158,7 @@ test('setAnkiConnectEnabled disables active integration and broadcasts changes',
     },
   };
 
-  registered.setAnkiConnectEnabled(false);
+  registered.setAnkiConnectEnabled!(false);
 
   assert.deepEqual(state.patches, [false]);
   assert.equal(destroyed, 1);
@@ -188,8 +188,8 @@ test('clearAnkiHistory and respondFieldGrouping execute runtime callbacks', () =
     deleteDuplicate: true,
     cancelled: false,
   };
-  registered.clearAnkiHistory();
-  registered.respondFieldGrouping(choice);
+  registered.clearAnkiHistory!();
+  registered.respondFieldGrouping!(choice);
 
   options.getSubtitleTimingTracker = originalGetTracker;
 
@@ -201,7 +201,7 @@ test('clearAnkiHistory and respondFieldGrouping execute runtime callbacks', () =
 test('buildKikuMergePreview returns guard error when integration is missing', async () => {
   const { registered } = createHarness();
 
-  const result = await registered.buildKikuMergePreview({
+  const result = await registered.buildKikuMergePreview!({
     keepNoteId: 1,
     deleteNoteId: 2,
     deleteDuplicate: false,
@@ -227,7 +227,7 @@ test('buildKikuMergePreview delegates to integration when available', async () =
     },
   };
 
-  const result = await registered.buildKikuMergePreview({
+  const result = await registered.buildKikuMergePreview!({
     keepNoteId: 3,
     deleteNoteId: 4,
     deleteDuplicate: true,
@@ -240,7 +240,7 @@ test('buildKikuMergePreview delegates to integration when available', async () =
 test('searchJimakuEntries caps results and onDownloadedSubtitle sends sub-add to mpv', async () => {
   const { registered, state } = createHarness();
 
-  const searchResult = await registered.searchJimakuEntries({ query: 'test' });
+  const searchResult = await registered.searchJimakuEntries!({ query: 'test' });
   assert.deepEqual(state.fetchCalls, [
     {
       endpoint: '/api/entries/search',
@@ -250,6 +250,6 @@ test('searchJimakuEntries caps results and onDownloadedSubtitle sends sub-add to
   assert.equal((searchResult as { ok: boolean }).ok, true);
   assert.equal((searchResult as { data: unknown[] }).data.length, 2);
 
-  registered.onDownloadedSubtitle('/tmp/subtitle.ass');
+  registered.onDownloadedSubtitle!('/tmp/subtitle.ass');
   assert.deepEqual(state.sentCommands, [{ command: ['sub-add', '/tmp/subtitle.ass', 'select'] }]);
 });

src/core/services/app-ready.test.ts

@@ -209,30 +209,31 @@ test('runAppReadyRuntime aggregates multiple critical anki mapping errors', asyn
 
   await runAppReadyRuntime(deps);
 
+  const firstErrorSet = capturedErrors[0]!;
   assert.equal(capturedErrors.length, 1);
-  assert.equal(capturedErrors[0].length, 5);
+  assert.equal(firstErrorSet.length, 5);
   assert.ok(
-    capturedErrors[0].includes(
+    firstErrorSet.includes(
       'ankiConnect.fields.audio must be a non-empty string when ankiConnect is enabled.',
     ),
   );
   assert.ok(
-    capturedErrors[0].includes(
+    firstErrorSet.includes(
       'ankiConnect.fields.image must be a non-empty string when ankiConnect is enabled.',
     ),
   );
   assert.ok(
-    capturedErrors[0].includes(
+    firstErrorSet.includes(
       'ankiConnect.fields.sentence must be a non-empty string when ankiConnect is enabled.',
     ),
   );
   assert.ok(
-    capturedErrors[0].includes(
+    firstErrorSet.includes(
       'ankiConnect.fields.miscInfo must be a non-empty string when ankiConnect is enabled.',
     ),
   );
   assert.ok(
-    capturedErrors[0].includes(
+    firstErrorSet.includes(
       'ankiConnect.fields.translation must be a non-empty string when ankiConnect is enabled.',
     ),
   );

src/core/services/immersion-tracker-service.test.ts

@@ -124,8 +124,8 @@ testIfSqlite('persists and retrieves minimum immersion tracking fields', async (
 
     const summaries = await tracker.getSessionSummaries(10);
     assert.ok(summaries.length >= 1);
-    assert.ok(summaries[0].linesSeen >= 1);
-    assert.ok(summaries[0].cardsMined >= 2);
+    assert.ok(summaries[0]!.linesSeen >= 1);
+    assert.ok(summaries[0]!.cardsMined >= 2);
 
     tracker.destroy();
 
@@ -376,8 +376,8 @@ testIfSqlite('monthly rollups are grouped by calendar month', async () => {
     const videoRows = rows.filter((row) => row.videoId === 1);
 
     assert.equal(videoRows.length, 2);
-    assert.equal(videoRows[0].rollupDayOrMonth, 202602);
-    assert.equal(videoRows[1].rollupDayOrMonth, 202601);
+    assert.equal(videoRows[0]!.rollupDayOrMonth, 202602);
+    assert.equal(videoRows[1]!.rollupDayOrMonth, 202601);
   } finally {
     tracker?.destroy();
     cleanupDbPath(dbPath);

src/core/services/immersion-tracker-service.ts

@@ -1443,7 +1443,7 @@ export class ImmersionTrackerService {
         const parsed = new URL(mediaPath);
         const parts = parsed.pathname.split('/').filter(Boolean);
         if (parts.length > 0) {
-          const leaf = decodeURIComponent(parts[parts.length - 1]);
+          const leaf = decodeURIComponent(parts[parts.length - 1]!);
           return this.normalizeText(leaf.replace(/\.[^/.]+$/, ''));
         }
         return this.normalizeText(parsed.hostname) || 'unknown';

src/core/services/index.ts

@@ -35,7 +35,6 @@ export { createFrequencyDictionaryLookup } from './frequency-dictionary';
 export { createJlptVocabularyLookup } from './jlpt-vocab';
 export {
   getIgnoredPos1Entries,
-  JlptIgnoredPos1Entry,
   JLPT_EXCLUDED_TERMS,
   JLPT_IGNORED_MECAB_POS1,
   JLPT_IGNORED_MECAB_POS1_ENTRIES,
@@ -43,6 +42,7 @@ export {
   shouldIgnoreJlptByTerm,
   shouldIgnoreJlptForMecabPos1,
 } from './jlpt-token-filter';
+export type { JlptIgnoredPos1Entry } from './jlpt-token-filter';
 export { loadYomitanExtension } from './yomitan-extension-loader';
 export {
   getJimakuLanguagePreference,
@@ -72,8 +72,6 @@ export {
 export {
   MPV_REQUEST_ID_SECONDARY_SUB_VISIBILITY,
   MpvIpcClient,
-  MpvRuntimeClientLike,
-  MpvTrackProperty,
   playNextSubtitleRuntime,
   replayCurrentSubtitleRuntime,
   resolveCurrentAudioStreamIndex,
@@ -81,6 +79,7 @@ export {
   setMpvSubVisibilityRuntime,
   showMpvOsdRuntime,
 } from './mpv';
+export type { MpvRuntimeClientLike, MpvTrackProperty } from './mpv';
 export {
   applyMpvSubtitleRenderMetricsPatch,
   DEFAULT_MPV_SUBTITLE_RENDER_METRICS,

src/core/services/jellyfin-remote.test.ts

@@ -70,11 +70,11 @@ test('start posts capabilities on socket connect', async () => {
   });
 
   service.start();
-  sockets[0].emit('open');
+  sockets[0]!.emit('open');
   await new Promise((resolve) => setTimeout(resolve, 0));
 
   assert.equal(fetchCalls.length, 1);
-  assert.equal(fetchCalls[0].input, 'http://jellyfin.local:8096/Sessions/Capabilities/Full');
+  assert.equal(fetchCalls[0]!.input, 'http://jellyfin.local:8096/Sessions/Capabilities/Full');
   assert.equal(service.isConnected(), true);
 });
 
@@ -97,9 +97,9 @@ test('socket headers include jellyfin authorization metadata', () => {
 
   service.start();
   assert.equal(seenHeaders.length, 1);
-  assert.ok(seenHeaders[0].Authorization.includes('Client="SubMiner"'));
-  assert.ok(seenHeaders[0].Authorization.includes('DeviceId="device-auth"'));
-  assert.ok(seenHeaders[0]['X-Emby-Authorization']);
+  assert.ok(seenHeaders[0]!['Authorization']!.includes('Client="SubMiner"'));
+  assert.ok(seenHeaders[0]!['Authorization']!.includes('DeviceId="device-auth"'));
+  assert.ok(seenHeaders[0]!['X-Emby-Authorization']);
 });
 
 test('dispatches inbound Play, Playstate, and GeneralCommand messages', () => {
@@ -124,7 +124,7 @@ test('dispatches inbound Play, Playstate, and GeneralCommand messages', () => {
   });
 
   service.start();
-  const socket = sockets[0];
+  const socket = sockets[0]!;
   socket.emit('message', JSON.stringify({ MessageType: 'Play', Data: { ItemId: 'movie-1' } }));
   socket.emit(
     'message',
@@ -174,13 +174,13 @@ test('schedules reconnect with bounded exponential backoff', () => {
   });
 
   service.start();
-  sockets[0].emit('close');
+  sockets[0]!.emit('close');
   pendingTimers.shift()?.();
-  sockets[1].emit('close');
+  sockets[1]!.emit('close');
   pendingTimers.shift()?.();
-  sockets[2].emit('close');
+  sockets[2]!.emit('close');
   pendingTimers.shift()?.();
-  sockets[3].emit('close');
+  sockets[3]!.emit('close');
 
   assert.deepEqual(delays, [100, 200, 400, 400]);
   assert.equal(sockets.length, 4);
@@ -216,7 +216,7 @@ test('Jellyfin remote stop prevents further reconnect/network activity', () => {
 
   service.start();
   assert.equal(sockets.length, 1);
-  sockets[0].emit('close');
+  sockets[0]!.emit('close');
   assert.equal(pendingTimers.length, 1);
 
   service.stop();
@@ -252,7 +252,7 @@ test('reportProgress posts timeline payload and treats failure as non-fatal', as
   });
 
   service.start();
-  sockets[0].emit('open');
+  sockets[0]!.emit('open');
   await new Promise((resolve) => setTimeout(resolve, 0));
 
   const expectedPayload = buildJellyfinTimelinePayload({
@@ -310,7 +310,7 @@ test('advertiseNow validates server registration using Sessions endpoint', async
   });
 
   service.start();
-  sockets[0].emit('open');
+  sockets[0]!.emit('open');
   const ok = await service.advertiseNow();
   assert.equal(ok, true);
   assert.ok(calls.some((url) => url.endsWith('/Sessions')));

src/core/services/jellyfin.test.ts

@@ -119,7 +119,7 @@ test('listItems supports search and formats title', async () => {
         limit: 25,
       },
     );
-    assert.equal(items[0].title, 'Space Show S01E02 Pilot');
+    assert.equal(items[0]!.title, 'Space Show S01E02 Pilot');
   } finally {
     globalThis.fetch = originalFetch;
   }
@@ -338,14 +338,14 @@ test('listSubtitleTracks returns all subtitle streams with delivery urls', async
       [2, 3, 4],
     );
     assert.equal(
-      tracks[0].deliveryUrl,
+      tracks[0]!.deliveryUrl,
       'http://jellyfin.local/Videos/movie-1/ms-1/Subtitles/2/Stream.srt?api_key=token',
     );
     assert.equal(
-      tracks[1].deliveryUrl,
+      tracks[1]!.deliveryUrl,
       'http://jellyfin.local/Videos/movie-1/ms-1/Subtitles/3/Stream.srt?api_key=token',
     );
-    assert.equal(tracks[2].deliveryUrl, 'https://cdn.example.com/subs.srt');
+    assert.equal(tracks[2]!.deliveryUrl, 'https://cdn.example.com/subs.srt');
   } finally {
     globalThis.fetch = originalFetch;
   }
@@ -556,9 +556,9 @@ test('listSubtitleTracks falls back from PlaybackInfo to item media sources', as
     );
     assert.equal(requestCount, 2);
     assert.equal(tracks.length, 1);
-    assert.equal(tracks[0].index, 11);
+    assert.equal(tracks[0]!.index, 11);
     assert.equal(
-      tracks[0].deliveryUrl,
+      tracks[0]!.deliveryUrl,
       'http://jellyfin.local/Videos/movie-fallback/ms-fallback/Subtitles/11/Stream.srt?api_key=token',
     );
   } finally {

src/core/services/mpv-protocol.test.ts

@@ -177,8 +177,8 @@ test('splitMpvMessagesFromBuffer parses complete lines and preserves partial buf
 
   assert.equal(parsed.messages.length, 2);
   assert.equal(parsed.nextBuffer, '{"partial"');
-  assert.equal(parsed.messages[0].event, 'shutdown');
-  assert.equal(parsed.messages[1].name, 'media-title');
+  assert.equal(parsed.messages[0]!.event, 'shutdown');
+  assert.equal(parsed.messages[1]!.name, 'media-title');
 });
 
 test('splitMpvMessagesFromBuffer reports invalid JSON lines', () => {
@@ -189,7 +189,7 @@ test('splitMpvMessagesFromBuffer reports invalid JSON lines', () => {
   });
 
   assert.equal(errors.length, 1);
-  assert.equal(errors[0].line, '{invalid}');
+  assert.equal(errors[0]!.line, '{invalid}');
 });
 
 test('visibility and boolean parsers handle text values', () => {

src/core/services/mpv-transport.test.ts

@@ -84,11 +84,11 @@ test('scheduleMpvReconnect clears existing timer and increments attempt', () =>
 
   assert.equal(nextAttempt, 4);
   assert.equal(cleared.length, 1);
-  assert.equal(cleared[0], existing);
+  assert.equal(cleared[0]!, existing);
   assert.equal(setTimers.length, 1);
   assert.equal(calls.length, 1);
-  assert.equal(calls[0].attempt, 4);
-  assert.equal(calls[0].delay, getMpvReconnectDelay(3, true));
+  assert.equal(calls[0]!.attempt, 4);
+  assert.equal(calls[0]!.delay, getMpvReconnectDelay(3, true));
   assert.equal(connected, 1);
 });
 

src/core/services/mpv.test.ts

@@ -54,8 +54,8 @@ test('MpvIpcClient handles sub-text property change and broadcasts tokenized sub
   });
 
   assert.equal(events.length, 1);
-  assert.equal(events[0].text, '字幕');
-  assert.equal(events[0].isOverlayVisible, false);
+  assert.equal(events[0]!.text, '字幕');
+  assert.equal(events[0]!.isOverlayVisible, false);
 });
 
 test('MpvIpcClient parses JSON line protocol in processBuffer', () => {
@@ -70,8 +70,8 @@ test('MpvIpcClient parses JSON line protocol in processBuffer', () => {
   (client as any).processBuffer();
 
   assert.equal(seen.length, 2);
-  assert.equal(seen[0].name, 'path');
-  assert.equal(seen[1].request_id, 1);
+  assert.equal(seen[0]!.name, 'path');
+  assert.equal(seen[1]!.request_id, 1);
   assert.equal((client as any).buffer, '{"partial":');
 });
 

src/core/services/overlay-content-measurement.test.ts

@@ -83,5 +83,5 @@ test('overlay measurement store rate-limits invalid payload warnings', () => {
   now = 11_000;
   store.report({ layer: 'visible' });
   assert.equal(warnings.length, 1);
-  assert.match(warnings[0], /Dropped 3 invalid measurement payload/);
+  assert.match(warnings[0]!, /Dropped 3 invalid measurement payload/);
 });

src/core/services/overlay-drop.ts

@@ -23,7 +23,7 @@ const VIDEO_EXTENSIONS = new Set([
 ]);
 
 function getPathExtension(pathValue: string): string {
-  const normalized = pathValue.split(/[?#]/, 1)[0];
+  const normalized = pathValue.split(/[?#]/, 1)[0] ?? '';
   const dot = normalized.lastIndexOf('.');
   return dot >= 0 ? normalized.slice(dot).toLowerCase() : '';
 }

src/core/services/shortcut-fallback.ts

@@ -26,7 +26,7 @@ export function shortcutMatchesInputForLocalFallback(
   const parts = normalized.split('+').filter(Boolean);
   if (parts.length === 0) return false;
 
-  const keyToken = parts[parts.length - 1];
+  const keyToken = parts[parts.length - 1]!;
   const modifierTokens = new Set(parts.slice(0, -1));
   const allowedModifiers = new Set(['shift', 'alt', 'meta', 'control', 'commandorcontrol']);
   for (const token of modifierTokens) {

src/core/services/subsync.test.ts

@@ -339,6 +339,6 @@ test('runSubsyncManual resolves string sid values from mpv stream properties', a
   assert.equal(syncOutputIndex >= 0, true);
   const outputPath = ffArgs[syncOutputIndex + 1];
   assert.equal(typeof outputPath, 'string');
-  assert.ok(outputPath.length > 0);
-  assert.equal(fs.readFileSync(outputPath, 'utf8'), '');
+  assert.ok(outputPath!.length > 0);
+  assert.equal(fs.readFileSync(outputPath!, 'utf8'), '');
 });

src/core/services/subtitle-position.ts

@@ -28,7 +28,8 @@ export function cycleSecondarySubMode(deps: CycleSecondarySubModeDeps): void {
 
   const currentMode = deps.getSecondarySubMode();
   const currentIndex = SECONDARY_SUB_CYCLE.indexOf(currentMode);
-  const nextMode = SECONDARY_SUB_CYCLE[(currentIndex + 1) % SECONDARY_SUB_CYCLE.length];
+  const safeIndex = currentIndex >= 0 ? currentIndex : 0;
+  const nextMode = SECONDARY_SUB_CYCLE[(safeIndex + 1) % SECONDARY_SUB_CYCLE.length]!;
   deps.setSecondarySubMode(nextMode);
   deps.broadcastSecondarySubMode(nextMode);
   deps.showMpvOsd(`Secondary subtitle: ${nextMode}`);

src/core/services/subtitle-ws.ts

@@ -82,8 +82,9 @@ export function serializeSubtitleMarkup(
     const klass = computeWordClass(token, options);
     const parts = token.surface.split('\n');
     for (let index = 0; index < parts.length; index += 1) {
-      if (parts[index]) {
-        chunks.push(`<span class="${klass}">${escapeHtml(parts[index])}</span>`);
+      const part = parts[index];
+      if (part) {
+        chunks.push(`<span class="${klass}">${escapeHtml(part)}</span>`);
       }
       if (index < parts.length - 1) {
         chunks.push('<br>');

src/core/services/texthooker.ts

@@ -20,7 +20,7 @@ export class Texthooker {
     }
 
     this.server = http.createServer((req, res) => {
-      const urlPath = (req.url || '/').split('?')[0];
+      const urlPath = (req.url || '/').split('?')[0] ?? '/';
       const filePath = path.join(texthookerPath, urlPath === '/' ? 'index.html' : urlPath);
 
       const ext = path.extname(filePath);

src/core/services/tokenizer.ts

@@ -377,7 +377,7 @@ function isRepeatedKanaSfx(text: string): boolean {
   let hasAdjacentRepeat = false;
 
   for (let i = 0; i < chars.length; i += 1) {
-    const char = chars[i];
+    const char = chars[i]!;
     counts.set(char, (counts.get(char) ?? 0) + 1);
     if (i > 0 && chars[i] === chars[i - 1]) {
       hasAdjacentRepeat = true;

src/core/services/yomitan-settings.ts

@@ -73,7 +73,8 @@ export function openYomitanSettingsWindow(options: OpenYomitanSettingsWindowOpti
 
   setTimeout(() => {
     if (!settingsWindow.isDestroyed()) {
-      settingsWindow.setSize(settingsWindow.getSize()[0], settingsWindow.getSize()[1]);
+      const [width = 0, height = 0] = settingsWindow.getSize();
+      settingsWindow.setSize(width, height);
       settingsWindow.webContents.invalidate();
       settingsWindow.show();
     }