Update eslint rules (#710)

71 files changed, 299 insertions, 292 deletions

diff --git a/.eslintrc.json b/.eslintrc.json
index 8147659f..d3509d85 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -74,8 +74,8 @@
         "no-implied-eval": "error",
         "no-new": "error",
         "no-new-native-nonconstructor": "error",
-        "no-octal": "off",
-        "no-octal-escape": "off",
+        "no-octal": "error",
+        "no-octal-escape": "error",
         "no-param-reassign": "off",
         "no-promise-executor-return": "error",
         "no-prototype-builtins": "error",
@@ -394,9 +394,9 @@
                 "plugin:@typescript-eslint/recommended-type-checked"
             ],
             "rules": {
-                "@typescript-eslint/no-floating-promises": "off",
+                "@typescript-eslint/no-floating-promises": ["error", {"ignoreIIFE": true}],
                 "@typescript-eslint/no-misused-promises": "off",
-                "@typescript-eslint/no-redundant-type-constituents": "off",
+                "@typescript-eslint/no-redundant-type-constituents": "error",
                 "@typescript-eslint/no-unsafe-argument": "off",
                 "@typescript-eslint/no-unsafe-assignment": "off",
                 "@typescript-eslint/no-unsafe-call": "off",
diff --git a/dev/bin/build-libs.js b/dev/bin/build-libs.js
index a614407e..bd7c53cc 100644
--- a/dev/bin/build-libs.js
+++ b/dev/bin/build-libs.js
@@ -18,4 +18,4 @@
 
 import {buildLibs} from '../build-libs.js';
 
-buildLibs();
+await buildLibs();
diff --git a/dev/bin/build.js b/dev/bin/build.js
index e22159d6..7a954c66 100644
--- a/dev/bin/build.js
+++ b/dev/bin/build.js
@@ -280,4 +280,4 @@ export async function main(argv) {
     }
 }
 
-testMain(main, process.argv.slice(2));
+await testMain(main, process.argv.slice(2));
diff --git a/dev/bin/dictionary-validate.js b/dev/bin/dictionary-validate.js
index e7c3562e..a2da31e5 100644
--- a/dev/bin/dictionary-validate.js
+++ b/dev/bin/dictionary-validate.js
@@ -39,4 +39,4 @@ async function main() {
     await testDictionaryFiles(mode, dictionaryFileNames);
 }
 
-main();
+await main();
diff --git a/ext/js/app/frontend.js b/ext/js/app/frontend.js
index 04f8673f..0b7393a0 100644
--- a/ext/js/app/frontend.js
+++ b/ext/js/app/frontend.js
@@ -256,14 +256,14 @@ export class Frontend {
      * @returns {void}
      */
     _onActionScanSelectedText() {
-        this._scanSelectedText(false);
+        void this._scanSelectedText(false);
     }
 
     /**
      * @returns {void}
      */
     _onActionScanTextAtCaret() {
-        this._scanSelectedText(true);
+        void this._scanSelectedText(true);
     }
 
     // API message handlers
@@ -320,7 +320,7 @@ export class Frontend {
      * @returns {void}
      */
     _onResize() {
-        this._updatePopupPosition();
+        void this._updatePopupPosition();
     }
 
     /** @type {import('extension').ChromeRuntimeOnMessageCallback<import('application').ApiMessageAny>} */
@@ -347,7 +347,7 @@ export class Frontend {
      * @returns {void}
      */
     _onVisualViewportScroll() {
-        this._updatePopupPosition();
+        void this._updatePopupPosition();
     }
 
     /**
@@ -423,8 +423,8 @@ export class Frontend {
     _clearSelection(passive) {
         this._stopClearSelectionDelayed();
         if (this._popup !== null) {
-            this._popup.clearAutoPlayTimer();
-            this._popup.hide(!passive);
+            void this._popup.clearAutoPlayTimer();
+            void this._popup.hide(!passive);
             this._isPointerOverPopup = false;
         }
         this._textScanner.clearSelection();
@@ -630,7 +630,7 @@ export class Frontend {
         });
         popup.on('offsetNotFound', () => {
             this._allowRootFramePopupProxy = false;
-            this._updatePopup();
+            void this._updatePopup();
         });
         return popup;
     }
@@ -679,7 +679,7 @@ export class Frontend {
      * @param {import('text-source').TextSource} textSource
      */
     _showExtensionUnloaded(textSource) {
-        this._showPopupContent(textSource, null, null);
+        void this._showPopupContent(textSource, null, null);
     }
 
     /**
@@ -726,7 +726,7 @@ export class Frontend {
             details.params.full = textSource.fullContent;
             details.params['full-visible'] = 'true';
         }
-        this._showPopupContent(textSource, optionsContext, details);
+        void this._showPopupContent(textSource, optionsContext, details);
     }
 
     /**
@@ -792,9 +792,9 @@ export class Frontend {
 
         this._contentScale = contentScale;
         if (this._popup !== null) {
-            this._popup.setContentScale(this._contentScale);
+            void this._popup.setContentScale(this._contentScale);
         }
-        this._updatePopupPosition();
+        void this._updatePopupPosition();
     }
 
     /**
@@ -807,7 +807,7 @@ export class Frontend {
             this._popup !== null &&
             await this._popup.isVisible()
         ) {
-            this._showPopupContent(textSource, null, null);
+            void this._showPopupContent(textSource, null, null);
         }
     }
 
@@ -818,9 +818,9 @@ export class Frontend {
         /** @type {import('application').ApiMessageNoFrameId<'frontendReady'>} */
         const message = {action: 'frontendReady', params: {frameId: this._application.frameId}};
         if (targetFrameId === null) {
-            this._application.api.broadcastTab(message);
+            void this._application.api.broadcastTab(message);
         } else {
-            this._application.api.sendMessageToFrame(targetFrameId, message);
+            void this._application.api.sendMessageToFrame(targetFrameId, message);
         }
     }
 
@@ -864,7 +864,7 @@ export class Frontend {
             }
 
             chrome.runtime.onMessage.addListener(onMessage);
-            this._application.api.broadcastTab({action: 'frontendRequestReadyBroadcast', params: {frameId: this._application.frameId}});
+            void this._application.api.broadcastTab({action: 'frontendRequestReadyBroadcast', params: {frameId: this._application.frameId}});
         });
     }
 
@@ -950,7 +950,7 @@ export class Frontend {
     _prepareSiteSpecific() {
         switch (location.hostname.toLowerCase()) {
             case 'docs.google.com':
-                this._prepareGoogleDocs();
+                void this._prepareGoogleDocs();
                 break;
         }
     }
diff --git a/ext/js/app/popup.js b/ext/js/app/popup.js
index c9011932..7a8b3f8c 100644
--- a/ext/js/app/popup.js
+++ b/ext/js/app/popup.js
@@ -304,7 +304,7 @@ export class Popup extends EventDispatcher {
         await this._show(sourceRects, writingMode);
 
         if (displayDetails !== null) {
-            this._invokeSafe('displaySetContent', {details: displayDetails});
+            void this._invokeSafe('displaySetContent', {details: displayDetails});
         }
     }
 
@@ -662,7 +662,7 @@ export class Popup extends EventDispatcher {
         if (this._visibleValue === value) { return; }
         this._visibleValue = value;
         this._frame.style.setProperty('visibility', value ? 'visible' : 'hidden', 'important');
-        this._invokeSafe('displayVisibilityChanged', {value});
+        void this._invokeSafe('displayVisibilityChanged', {value});
     }
 
     /**
@@ -1028,7 +1028,7 @@ export class Popup extends EventDispatcher {
         this._useSecureFrameUrl = general.useSecurePopupFrameUrl;
         this._useShadowDom = general.usePopupShadowDom;
         this._customOuterCss = general.customPopupOuterCss;
-        this.updateTheme();
+        void this.updateTheme();
     }
 
     /**
diff --git a/ext/js/application.js b/ext/js/application.js
index ec5c7e02..92815b8e 100644
--- a/ext/js/application.js
+++ b/ext/js/application.js
@@ -172,7 +172,7 @@ export class Application extends EventDispatcher {
     ready() {
         if (this._isReady) { return; }
         this._isReady = true;
-        this._webExtension.sendMessagePromise({action: 'applicationReady'});
+        void this._webExtension.sendMessagePromise({action: 'applicationReady'});
     }
 
     /** */
diff --git a/ext/js/background/backend.js b/ext/js/background/backend.js
index c0410ab8..8b0853d2 100644
--- a/ext/js/background/backend.js
+++ b/ext/js/background/backend.js
@@ -216,7 +216,7 @@ export class Backend {
                     this._prepareCompleteReject(error);
                 }
             );
-            promise.finally(() => this._updateBadge());
+            void promise.finally(() => this._updateBadge());
             this._preparePromise = promise;
         }
         return this._prepareCompletePromise;
@@ -282,7 +282,7 @@ export class Backend {
 
             /** @type {import('language-transformer').LanguageTransformDescriptor} */
             const descriptor = await fetchJson('/data/language/japanese-transforms.json');
-            this._translator.prepare(descriptor);
+            void this._translator.prepare(descriptor);
 
             await this._optionsUtil.prepare();
             this._defaultAnkiFieldTemplates = (await fetchText('/data/templates/default-anki-field-templates.handlebars')).trim();
@@ -292,7 +292,7 @@ export class Backend {
 
             const options = this._getProfileOptions({current: true}, false);
             if (options.general.showGuide) {
-                this._openWelcomeGuidePageOnce();
+                void this._openWelcomeGuidePageOnce();
             }
 
             this._clipboardMonitor.on('change', this._onClipboardTextChange.bind(this));
@@ -409,7 +409,7 @@ export class Backend {
      * @returns {void}
      */
     _onPermissionsChanged() {
-        this._checkPermissions();
+        void this._checkPermissions();
     }
 
     /**
@@ -417,7 +417,7 @@ export class Backend {
      */
     _onInstalled({reason}) {
         if (reason !== 'install') { return; }
-        this._requestPersistentStorage();
+        void this._requestPersistentStorage();
     }
 
     // Message handlers
@@ -1047,7 +1047,7 @@ export class Backend {
         if (this._searchPopupTabCreatePromise === null) {
             const promise = this._getOrCreateSearchPopup();
             this._searchPopupTabCreatePromise = promise;
-            promise.then(() => { this._searchPopupTabCreatePromise = null; });
+            void promise.then(() => { this._searchPopupTabCreatePromise = null; });
         }
         return this._searchPopupTabCreatePromise;
     }
@@ -1239,7 +1239,7 @@ export class Backend {
             this._clipboardMonitor.stop();
         }
 
-        this._accessibilityController.update(this._getOptionsFull(false));
+        void this._accessibilityController.update(this._getOptionsFull(false));
 
         this._sendMessageAllTabsIgnoreResponse({action: 'applicationOptionsUpdated', params: {source}});
     }
@@ -1612,16 +1612,16 @@ export class Backend {
         }
 
         if (color !== null && typeof chrome.action.setBadgeBackgroundColor === 'function') {
-            chrome.action.setBadgeBackgroundColor({color});
+            void chrome.action.setBadgeBackgroundColor({color});
         }
         if (text !== null && typeof chrome.action.setBadgeText === 'function') {
-            chrome.action.setBadgeText({text});
+            void chrome.action.setBadgeText({text});
         }
         if (typeof chrome.action.setTitle === 'function') {
             if (status !== null) {
                 title = `${title} - ${status}`;
             }
-            chrome.action.setTitle({title});
+            void chrome.action.setTitle({title});
         }
     }
 
@@ -2339,7 +2339,7 @@ export class Backend {
      * @param {import('backend').DatabaseUpdateCause} cause
      */
     _triggerDatabaseUpdated(type, cause) {
-        this._translator.clearDatabaseCaches();
+        void this._translator.clearDatabaseCaches();
         this._sendMessageAllTabsIgnoreResponse({action: 'applicationDatabaseUpdated', params: {type, cause}});
     }
 
@@ -2468,12 +2468,13 @@ export class Backend {
      * @returns {Promise<void>}
      */
     async _openWelcomeGuidePageOnce() {
-        chrome.storage.session.get(['openedWelcomePage']).then((result) => {
-            if (!result.openedWelcomePage) {
-                this._openWelcomeGuidePage();
-                chrome.storage.session.set({openedWelcomePage: true});
-            }
-        });
+        const result = await chrome.storage.session.get(['openedWelcomePage']);
+        if (!result.openedWelcomePage) {
+            await Promise.all([
+                this._openWelcomeGuidePage(),
+                chrome.storage.session.set({openedWelcomePage: true})
+            ]);
+        }
     }
 
     /**
diff --git a/ext/js/background/background-main.js b/ext/js/background/background-main.js
index b7e45cd1..6d94b714 100644
--- a/ext/js/background/background-main.js
+++ b/ext/js/background/background-main.js
@@ -29,4 +29,4 @@ async function main() {
     await backend.prepare();
 }
 
-main();
+void main();
diff --git a/ext/js/background/offscreen-proxy.js b/ext/js/background/offscreen-proxy.js
index 5a79f41a..c888fe29 100644
--- a/ext/js/background/offscreen-proxy.js
+++ b/ext/js/background/offscreen-proxy.js
@@ -259,7 +259,7 @@ export class ClipboardReaderProxy {
     set browser(value) {
         if (this._browser === value) { return; }
         this._browser = value;
-        this._offscreen.sendMessagePromise({action: 'clipboardSetBrowserOffscreen', params: {value}});
+        void this._offscreen.sendMessagePromise({action: 'clipboardSetBrowserOffscreen', params: {value}});
     }
 
     /**
diff --git a/ext/js/comm/clipboard-monitor.js b/ext/js/comm/clipboard-monitor.js
index 6ee93f57..a7cd8833 100644
--- a/ext/js/comm/clipboard-monitor.js
+++ b/ext/js/comm/clipboard-monitor.js
@@ -82,7 +82,7 @@ export class ClipboardMonitor extends EventDispatcher {
 
         this._timerToken = token;
 
-        intervalCallback();
+        void intervalCallback();
     }
 
     /**
diff --git a/ext/js/comm/frame-ancestry-handler.js b/ext/js/comm/frame-ancestry-handler.js
index 92ed3b8c..39288738 100644
--- a/ext/js/comm/frame-ancestry-handler.js
+++ b/ext/js/comm/frame-ancestry-handler.js
@@ -176,7 +176,7 @@ export class FrameAncestryHandler {
         const {params} = /** @type {import('core').SerializableObject} */ (data);
         if (typeof params !== 'object' || params === null) { return; }
 
-        this._onRequestFrameInfo(/** @type {import('core').SerializableObject} */ (params), source);
+        void this._onRequestFrameInfo(/** @type {import('core').SerializableObject} */ (params), source);
     }
 
     /**
diff --git a/ext/js/comm/frame-client.js b/ext/js/comm/frame-client.js
index 62db1edd..3a41ab0f 100644
--- a/ext/js/comm/frame-client.js
+++ b/ext/js/comm/frame-client.js
@@ -112,7 +112,7 @@ export class FrameClient {
 
             /** @type {import('extension').ChromeRuntimeOnMessageCallback<import('application').ApiMessageAny>} */
             const onMessage = (message) => {
-                onMessageInner(message);
+                void onMessageInner(message);
                 return false;
             };
 
diff --git a/ext/js/comm/frame-endpoint.js b/ext/js/comm/frame-endpoint.js
index d2002d2e..69d28a1e 100644
--- a/ext/js/comm/frame-endpoint.js
+++ b/ext/js/comm/frame-endpoint.js
@@ -46,7 +46,7 @@ export class FrameEndpoint {
         }
         /** @type {import('frame-client').FrameEndpointReadyDetails} */
         const details = {secret: this._secret};
-        this._api.broadcastTab({action: 'frameEndpointReady', params: details});
+        void this._api.broadcastTab({action: 'frameEndpointReady', params: details});
     }
 
     /**
@@ -88,6 +88,6 @@ export class FrameEndpoint {
         this._eventListeners.removeAllEventListeners();
         /** @type {import('frame-client').FrameEndpointConnectedDetails} */
         const details = {secret, token};
-        this._api.sendMessageToFrame(hostFrameId, {action: 'frameEndpointConnected', params: details});
+        void this._api.sendMessageToFrame(hostFrameId, {action: 'frameEndpointConnected', params: details});
     }
 }
diff --git a/ext/js/data/anki-note-builder.js b/ext/js/data/anki-note-builder.js
index 52160abc..32d4b593 100644
--- a/ext/js/data/anki-note-builder.js
+++ b/ext/js/data/anki-note-builder.js
@@ -286,7 +286,7 @@ export class AnkiNoteBuilder {
     _runBatchedRequestsDelayed() {
         if (this._batchedRequestsQueued) { return; }
         this._batchedRequestsQueued = true;
-        Promise.resolve().then(() => {
+        void Promise.resolve().then(() => {
             this._batchedRequestsQueued = false;
             this._runBatchedRequests();
         });
@@ -322,7 +322,7 @@ export class AnkiNoteBuilder {
 
         this._batchedRequests.length = 0;
 
-        this._resolveBatchedRequests(items, allRequests);
+        void this._resolveBatchedRequests(items, allRequests);
     }
 
     /**
diff --git a/ext/js/data/options-util.js b/ext/js/data/options-util.js
index 7952eafc..8ef52972 100644
--- a/ext/js/data/options-util.js
+++ b/ext/js/data/options-util.js
@@ -1095,9 +1095,9 @@ export class OptionsUtil {
         }
 
         if (customTemplates && isObject(chrome.storage)) {
-            chrome.storage.session.set({needsCustomTemplatesWarning: true});
+            void chrome.storage.session.set({needsCustomTemplatesWarning: true});
             await this._createTab(chrome.runtime.getURL('/welcome.html'));
-            chrome.storage.session.set({openedWelcomePage: true});
+            void chrome.storage.session.set({openedWelcomePage: true});
         }
     }
 
diff --git a/ext/js/dictionary/dictionary-importer.js b/ext/js/dictionary/dictionary-importer.js
index eed7d9dd..fbfe40d0 100644
--- a/ext/js/dictionary/dictionary-importer.js
+++ b/ext/js/dictionary/dictionary-importer.js
@@ -187,7 +187,7 @@ export class DictionaryImporter {
             media: {total: media.length}
         };
         const summary = this._createSummary(dictionaryTitle, version, index, {prefixWildcardsSupported, counts});
-        dictionaryDatabase.bulkAdd('dictionaries', [summary], 0, 1);
+        await dictionaryDatabase.bulkAdd('dictionaries', [summary], 0, 1);
 
         // Add data
         /** @type {Error[]} */
diff --git a/ext/js/dictionary/dictionary-worker-handler.js b/ext/js/dictionary/dictionary-worker-handler.js
index 1c11be93..4e263c21 100644
--- a/ext/js/dictionary/dictionary-worker-handler.js
+++ b/ext/js/dictionary/dictionary-worker-handler.js
@@ -41,13 +41,13 @@ export class DictionaryWorkerHandler {
         const {action, params} = event.data;
         switch (action) {
             case 'importDictionary':
-                this._onMessageWithProgress(params, this._importDictionary.bind(this));
+                void this._onMessageWithProgress(params, this._importDictionary.bind(this));
                 break;
             case 'deleteDictionary':
-                this._onMessageWithProgress(params, this._deleteDictionary.bind(this));
+                void this._onMessageWithProgress(params, this._deleteDictionary.bind(this));
                 break;
             case 'getDictionaryCounts':
-                this._onMessageWithProgress(params, this._getDictionaryCounts.bind(this));
+                void this._onMessageWithProgress(params, this._getDictionaryCounts.bind(this));
                 break;
             case 'getImageDetails.response':
                 this._mediaLoader.handleMessage(params);
@@ -95,7 +95,7 @@ export class DictionaryWorkerHandler {
                 errors: errors.map((error) => ExtensionError.serialize(error))
             };
         } finally {
-            dictionaryDatabase.close();
+            void dictionaryDatabase.close();
         }
     }
 
@@ -109,7 +109,7 @@ export class DictionaryWorkerHandler {
         try {
             return await dictionaryDatabase.deleteDictionary(dictionaryTitle, 1000, onProgress);
         } finally {
-            dictionaryDatabase.close();
+            void dictionaryDatabase.close();
         }
     }
 
@@ -122,7 +122,7 @@ export class DictionaryWorkerHandler {
         try {
             return await dictionaryDatabase.getDictionaryCounts(dictionaryNames, getTotal);
         } finally {
-            dictionaryDatabase.close();
+            void dictionaryDatabase.close();
         }
     }
 
diff --git a/ext/js/dictionary/dictionary-worker.js b/ext/js/dictionary/dictionary-worker.js
index 7a9e1114..bd6d5345 100644
--- a/ext/js/dictionary/dictionary-worker.js
+++ b/ext/js/dictionary/dictionary-worker.js
@@ -126,7 +126,7 @@ export class DictionaryWorker {
                 {
                     const {worker} = details;
                     if (worker === null) { return; }
-                    this._onMessageGetImageDetails(params, worker);
+                    void this._onMessageGetImageDetails(params, worker);
                 }
                 break;
         }
diff --git a/ext/js/display/display-anki.js b/ext/js/display/display-anki.js
index 03daf003..fb7bd85f 100644
--- a/ext/js/display/display-anki.js
+++ b/ext/js/display/display-anki.js
@@ -223,7 +223,7 @@ export class DisplayAnki {
         this._modeOptions.set('term-kanji', terms);
         this._modeOptions.set('term-kana', terms);
 
-        this._updateAnkiFieldTemplates(options);
+        void this._updateAnkiFieldTemplates(options);
     }
 
     /** */
@@ -258,7 +258,7 @@ export class DisplayAnki {
 
     /** */
     _onContentUpdateComplete() {
-        this._updateDictionaryEntryDetails();
+        void this._updateDictionaryEntryDetails();
     }
 
     /**
@@ -277,7 +277,7 @@ export class DisplayAnki {
         const mode = this._getValidCreateMode(element.dataset.mode);
         if (mode === null) { return; }
         const index = this._display.getElementDictionaryEntryIndex(element);
-        this._addAnkiNote(index, mode);
+        void this._addAnkiNote(index, mode);
     }
 
     /**
@@ -444,7 +444,7 @@ export class DisplayAnki {
      */
     _tryAddAnkiNoteForSelectedEntry(mode) {
         const index = this._display.selectedIndex;
-        this._addAnkiNote(index, mode);
+        void this._addAnkiNote(index, mode);
     }
 
     /**
@@ -783,7 +783,7 @@ export class DisplayAnki {
         if (e.shiftKey) {
             this._showViewNotesMenu(element);
         } else {
-            this._viewNotes(element);
+            void this._viewNotes(element);
         }
     }
 
@@ -804,7 +804,7 @@ export class DisplayAnki {
         switch (action) {
             case 'viewNotes':
                 if (item !== null) {
-                    this._viewNotes(item);
+                    void this._viewNotes(item);
                 }
                 break;
         }
@@ -927,7 +927,7 @@ export class DisplayAnki {
         const index = this._display.selectedIndex;
         const button = this._getViewNoteButton(index);
         if (button !== null) {
-            this._viewNotes(button);
+            void this._viewNotes(button);
         }
     }
 
diff --git a/ext/js/display/display-audio.js b/ext/js/display/display-audio.js
index 5f4131d0..d19a448c 100644
--- a/ext/js/display/display-audio.js
+++ b/ext/js/display/display-audio.js
@@ -225,7 +225,7 @@ export class DisplayAudio {
 
         const callback = () => {
             this._autoPlayAudioTimer = null;
-            this.playAudio(0, 0);
+            void this.playAudio(0, 0);
         };
 
         if (this._autoPlayAudioDelay > 0) {
@@ -248,7 +248,7 @@ export class DisplayAudio {
 
     /** */
     _onHotkeyActionPlayAudio() {
-        this.playAudio(this._display.selectedIndex, 0);
+        void this.playAudio(this._display.selectedIndex, 0);
     }
 
     /**
@@ -256,7 +256,7 @@ export class DisplayAudio {
      */
     _onHotkeyActionPlayAudioFromSource(source) {
         if (!(typeof source === 'string' || typeof source === 'undefined' || source === null)) { return; }
-        this.playAudio(this._display.selectedIndex, 0, source);
+        void this.playAudio(this._display.selectedIndex, 0, source);
     }
 
     /** @type {import('display').DirectApiHandler<'displayAudioClearAutoPlayTimer'>} */
@@ -317,7 +317,7 @@ export class DisplayAudio {
         if (e.shiftKey) {
             this._showAudioMenu(button, dictionaryEntryIndex, headwordIndex);
         } else {
-            this.playAudio(dictionaryEntryIndex, headwordIndex);
+            void this.playAudio(dictionaryEntryIndex, headwordIndex);
         }
     }
 
@@ -348,7 +348,7 @@ export class DisplayAudio {
                 if (shiftKey) {
                     e.preventDefault();
                 }
-                this._playAudioFromSource(dictionaryEntryIndex, headwordIndex, item);
+                void this._playAudioFromSource(dictionaryEntryIndex, headwordIndex, item);
                 break;
             case 'setPrimaryAudio':
                 e.preventDefault();
diff --git a/ext/js/display/display-content-manager.js b/ext/js/display/display-content-manager.js
index 81742279..c61c3aca 100644
--- a/ext/js/display/display-content-manager.js
+++ b/ext/js/display/display-content-manager.js
@@ -49,7 +49,7 @@ export class DisplayContentManager {
      * @param {import('display-content-manager').OnUnloadCallback} onUnload The callback that is executed when the media should be unloaded.
      */
     loadMedia(path, dictionary, onLoad, onUnload) {
-        this._loadMedia(path, dictionary, onLoad, onUnload);
+        void this._loadMedia(path, dictionary, onLoad, onUnload);
     }
 
     /**
@@ -65,7 +65,7 @@ export class DisplayContentManager {
 
         for (const map of this._mediaCache.values()) {
             for (const result of map.values()) {
-                this._revokeUrl(result);
+                void this._revokeUrl(result);
             }
         }
         this._mediaCache.clear();
diff --git a/ext/js/display/display-profile-selection.js b/ext/js/display/display-profile-selection.js
index 3df79b74..0aa08b00 100644
--- a/ext/js/display/display-profile-selection.js
+++ b/ext/js/display/display-profile-selection.js
@@ -63,7 +63,7 @@ export class DisplayProfileSelection {
         if (source === this._source) { return; }
         this._profileListNeedsUpdate = true;
         if (this._profilePanel.isVisible()) {
-            this._updateProfileList();
+            void this._updateProfileList();
         }
     }
 
@@ -84,7 +84,7 @@ export class DisplayProfileSelection {
         this._profileButton.classList.toggle('sidebar-button-highlight', visible);
         document.documentElement.dataset.profilePanelVisible = `${visible}`;
         if (visible && this._profileListNeedsUpdate) {
-            this._updateProfileList();
+            void this._updateProfileList();
         }
     }
 
@@ -121,7 +121,7 @@ export class DisplayProfileSelection {
     _onProfileRadioChange(index, e) {
         const element = /** @type {HTMLInputElement} */ (e.currentTarget);
         if (element.checked) {
-            this._setProfileCurrent(index);
+            void this._setProfileCurrent(index);
         }
     }
 
diff --git a/ext/js/display/display-resizer.js b/ext/js/display/display-resizer.js
index 7e346c7d..48117155 100644
--- a/ext/js/display/display-resizer.js
+++ b/ext/js/display/display-resizer.js
@@ -87,7 +87,7 @@ export class DisplayResizer {
         } else {
             if (this._startSize === null) { return; }
             const {clientX: x, clientY: y} = e;
-            this._updateFrameSize(x, y);
+            void this._updateFrameSize(x, y);
         }
     }
 
@@ -115,7 +115,7 @@ export class DisplayResizer {
         const primaryTouch = this._getTouch(e.changedTouches, this._touchIdentifier);
         if (primaryTouch === null) { return; }
         const {clientX: x, clientY: y} = primaryTouch;
-        this._updateFrameSize(x, y);
+        void this._updateFrameSize(x, y);
     }
 
     /**
@@ -138,7 +138,7 @@ export class DisplayResizer {
             documentElement.dataset.isResizing = 'true';
         }
 
-        this._initializeFrameResize(token);
+        void this._initializeFrameResize(token);
     }
 
     /**
@@ -163,7 +163,7 @@ export class DisplayResizer {
             documentElement.dataset.isResizing = 'true';
         }
 
-        this._initializeFrameResize(token);
+        void this._initializeFrameResize(token);
     }
 
     /**
diff --git a/ext/js/display/display.js b/ext/js/display/display.js
index 588508b5..d0edd0bd 100644
--- a/ext/js/display/display.js
+++ b/ext/js/display/display.js
@@ -364,7 +364,7 @@ export class Display extends EventDispatcher {
 
     /** */
     initializeState() {
-        this._onStateChanged();
+        void this._onStateChanged();
         if (this._frameEndpoint !== null) {
             this._frameEndpoint.signal();
         }
@@ -448,7 +448,7 @@ export class Display extends EventDispatcher {
             }
         });
 
-        this._updateNestedFrontend(options);
+        void this._updateNestedFrontend(options);
         this._updateContentTextScanner(options);
 
         this.trigger('optionsUpdated', {options});
@@ -523,10 +523,10 @@ export class Display extends EventDispatcher {
     close() {
         switch (this._pageType) {
             case 'popup':
-                this.invokeContentOrigin('frontendClosePopup', void 0);
+                void this.invokeContentOrigin('frontendClosePopup', void 0);
                 break;
             case 'search':
-                this._closeTab();
+                void this._closeTab();
                 break;
         }
     }
@@ -964,7 +964,7 @@ export class Display extends EventDispatcher {
     _onDebugLogClick(e) {
         const link = /** @type {HTMLElement} */ (e.currentTarget);
         const index = this.getElementDictionaryEntryIndex(link);
-        this._logDictionaryEntryData(index);
+        void this._logDictionaryEntryData(index);
     }
 
     /**
@@ -1064,7 +1064,7 @@ export class Display extends EventDispatcher {
         const {action} = e.detail;
         switch (action) {
             case 'log-debug-info':
-                this._logDictionaryEntryData(this.getElementDictionaryEntryIndex(node));
+                void this._logDictionaryEntryData(this.getElementDictionaryEntryIndex(node));
                 break;
         }
     }
@@ -1345,7 +1345,7 @@ export class Display extends EventDispatcher {
         const visible = this._isQueryParserVisible();
         this._queryParserContainer.hidden = !visible || text.length === 0;
         if (visible && this._queryParser.text !== text) {
-            this._setQueryParserText(text);
+            void this._setQueryParserText(text);
         }
     }
 
@@ -1738,7 +1738,7 @@ export class Display extends EventDispatcher {
         if (typeof this._contentOriginFrameId !== 'number') { return false; }
         const selection = window.getSelection();
         if (selection !== null && selection.toString().length > 0) { return false; }
-        this._copyHostSelectionSafe();
+        void this._copyHostSelectionSafe();
         return true;
     }
 
diff --git a/ext/js/display/option-toggle-hotkey-handler.js b/ext/js/display/option-toggle-hotkey-handler.js
index b2f48a3e..cf2d31e4 100644
--- a/ext/js/display/option-toggle-hotkey-handler.js
+++ b/ext/js/display/option-toggle-hotkey-handler.js
@@ -60,7 +60,7 @@ export class OptionToggleHotkeyHandler {
      */
     _onHotkeyActionToggleOption(argument) {
         if (typeof argument !== 'string') { return; }
-        this._toggleOption(argument);
+        void this._toggleOption(argument);
     }
 
     /**
diff --git a/ext/js/display/popup-main.js b/ext/js/display/popup-main.js
index fe1d20dd..b37a1ca4 100644
--- a/ext/js/display/popup-main.js
+++ b/ext/js/display/popup-main.js
@@ -42,7 +42,7 @@ await Application.main(true, async (application) => {
     displayAnki.prepare();
 
     const displayProfileSelection = new DisplayProfileSelection(display);
-    displayProfileSelection.prepare();
+    void displayProfileSelection.prepare();
 
     const displayResizer = new DisplayResizer(display);
     displayResizer.prepare();
diff --git a/ext/js/display/query-parser.js b/ext/js/display/query-parser.js
index edae96fb..875d9d5a 100644
--- a/ext/js/display/query-parser.js
+++ b/ext/js/display/query-parser.js
@@ -207,7 +207,7 @@ export class QueryParser extends EventDispatcher {
             scope: 'profile',
             optionsContext
         };
-        this._api.modifySettings([modification], 'search');
+        void this._api.modifySettings([modification], 'search');
     }
 
     /**
@@ -410,6 +410,6 @@ export class QueryParser extends EventDispatcher {
     _loadJapaneseWanakanaModule() {
         if (this._japaneseWanakanaModuleImport !== null) { return; }
         this._japaneseWanakanaModuleImport = import('../language/ja/japanese-wanakana.js');
-        this._japaneseWanakanaModuleImport.then((value) => { this._japaneseWanakanaModule = value; });
+        void this._japaneseWanakanaModuleImport.then((value) => { this._japaneseWanakanaModule = value; });
     }
 }
diff --git a/ext/js/display/search-display-controller.js b/ext/js/display/search-display-controller.js
index 23824aed..d8126027 100644
--- a/ext/js/display/search-display-controller.js
+++ b/ext/js/display/search-display-controller.js
@@ -298,7 +298,7 @@ export class SearchDisplayController {
             scope: 'profile',
             optionsContext: this._display.getOptionsContext()
         };
-        this._display.application.api.modifySettings([modification], 'search');
+        void this._display.application.api.modifySettings([modification], 'search');
     }
 
     /**
@@ -307,7 +307,7 @@ export class SearchDisplayController {
     _onClipboardMonitorEnableChange(e) {
         const element = /** @type {HTMLInputElement} */ (e.target);
         const enabled = element.checked;
-        this._setClipboardMonitorEnabled(enabled);
+        void this._setClipboardMonitorEnabled(enabled);
     }
 
     /** */
@@ -323,7 +323,7 @@ export class SearchDisplayController {
         const value = Number.parseInt(node.value, 10);
         const optionsFull = await this._display.application.api.optionsGetFull();
         if (typeof value === 'number' && Number.isFinite(value) && value >= 0 && value <= optionsFull.profiles.length) {
-            this._setPrimaryProfileIndex(value);
+            await this._setPrimaryProfileIndex(value);
         }
     }
 
diff --git a/ext/js/dom/dom-data-binder.js b/ext/js/dom/dom-data-binder.js
index be5633d7..d33f1a2b 100644
--- a/ext/js/dom/dom-data-binder.js
+++ b/ext/js/dom/dom-data-binder.js
@@ -133,7 +133,7 @@ export class DOMDataBinder {
         const value = this._getElementValue(observer.element);
         observer.value = value;
         observer.hasValue = true;
-        this._assignTasks.enqueue(observer, {value});
+        void this._assignTasks.enqueue(observer, {value});
     }
 
     /**
@@ -182,7 +182,7 @@ export class DOMDataBinder {
 
         element.addEventListener('change', observer.onChange, false);
 
-        this._updateTasks.enqueue(observer, {all: false});
+        void this._updateTasks.enqueue(observer, {all: false});
 
         return observer;
     }
diff --git a/ext/js/language/text-scanner.js b/ext/js/language/text-scanner.js
index d4caa643..64333093 100644
--- a/ext/js/language/text-scanner.js
+++ b/ext/js/language/text-scanner.js
@@ -542,7 +542,7 @@ export class TextScanner extends EventDispatcher {
         const inputInfo = this._getMatchingInputGroupFromEvent('mouse', 'mouseMove', e);
         if (inputInfo === null) { return; }
 
-        this._searchAtFromMouseMove(e.clientX, e.clientY, inputInfo);
+        void this._searchAtFromMouseMove(e.clientX, e.clientY, inputInfo);
     }
 
     /**
@@ -612,7 +612,7 @@ export class TextScanner extends EventDispatcher {
         const modifiers = getActiveModifiersAndButtons(e);
         const modifierKeys = getActiveModifiers(e);
         const inputInfo = this._createInputInfo(null, 'mouse', 'click', false, modifiers, modifierKeys);
-        this._searchAt(e.clientX, e.clientY, inputInfo);
+        void this._searchAt(e.clientX, e.clientY, inputInfo);
     }
 
     /** */
@@ -669,7 +669,7 @@ export class TextScanner extends EventDispatcher {
         const inputInfo = this._getMatchingInputGroupFromEvent('touch', 'touchStart', e);
         if (inputInfo === null || !(inputInfo.input !== null && inputInfo.input.scanOnTouchPress)) { return; }
 
-        this._searchAtFromTouchStart(x, y, inputInfo);
+        void this._searchAtFromTouchStart(x, y, inputInfo);
     }
 
     /**
@@ -703,7 +703,7 @@ export class TextScanner extends EventDispatcher {
         const inputInfo = this._getMatchingInputGroupFromEvent('touch', 'touchEnd', e);
         if (inputInfo === null || !(inputInfo.input !== null && inputInfo.input.scanOnTouchRelease)) { return; }
 
-        this._searchAtFromTouchEnd(x, y, inputInfo);
+        void this._searchAtFromTouchEnd(x, y, inputInfo);
     }
 
     /**
@@ -739,7 +739,7 @@ export class TextScanner extends EventDispatcher {
 
         const {input} = inputInfo;
         if (input !== null && input.scanOnTouchMove) {
-            this._searchAt(primaryTouch.clientX, primaryTouch.clientY, inputInfo);
+            void this._searchAt(primaryTouch.clientX, primaryTouch.clientY, inputInfo);
         }
 
         e.preventDefault(); // Disable scroll
@@ -899,7 +899,7 @@ export class TextScanner extends EventDispatcher {
         const inputInfo = this._getMatchingInputGroupFromEvent('touch', 'touchMove', e);
         if (inputInfo === null || !(inputInfo.input !== null && inputInfo.input.scanOnTouchMove)) { return; }
 
-        this._searchAt(e.clientX, e.clientY, inputInfo);
+        void this._searchAt(e.clientX, e.clientY, inputInfo);
     }
 
     /**
@@ -942,7 +942,7 @@ export class TextScanner extends EventDispatcher {
      */
     _onPenPointerOver(e) {
         this._penPointerState = 1;
-        this._searchAtFromPen(e, 'pointerOver', false);
+        void this._searchAtFromPen(e, 'pointerOver', false);
     }
 
     /**
@@ -950,7 +950,7 @@ export class TextScanner extends EventDispatcher {
      */
     _onPenPointerDown(e) {
         this._penPointerState = 2;
-        this._searchAtFromPen(e, 'pointerDown', true);
+        void this._searchAtFromPen(e, 'pointerDown', true);
     }
 
     /**
@@ -958,7 +958,7 @@ export class TextScanner extends EventDispatcher {
      */
     _onPenPointerMove(e) {
         if (this._penPointerState === 2 && (!this._preventScroll || !e.cancelable)) { return; }
-        this._searchAtFromPen(e, 'pointerMove', true);
+        void this._searchAtFromPen(e, 'pointerMove', true);
     }
 
     /**
@@ -967,7 +967,7 @@ export class TextScanner extends EventDispatcher {
     _onPenPointerUp(e) {
         this._penPointerState = 3;
         this._preventScroll = false;
-        this._searchAtFromPen(e, 'pointerUp', false);
+        void this._searchAtFromPen(e, 'pointerUp', false);
     }
 
     /** */
diff --git a/ext/js/pages/action-popup-main.js b/ext/js/pages/action-popup-main.js
index 0a14c669..8dca8934 100644
--- a/ext/js/pages/action-popup-main.js
+++ b/ext/js/pages/action-popup-main.js
@@ -37,14 +37,14 @@ class DisplayController {
         const manifest = chrome.runtime.getManifest();
 
         this._showExtensionInfo(manifest);
-        this._setupEnvironment();
+        void this._setupEnvironment();
         this._setupButtonEvents('.action-open-search', 'openSearchPage', chrome.runtime.getURL('/search.html'), this._onSearchClick.bind(this));
         this._setupButtonEvents('.action-open-info', 'openInfoPage', chrome.runtime.getURL('/info.html'));
 
         const optionsFull = await this._api.optionsGetFull();
         this._optionsFull = optionsFull;
 
-        this._setupHotkeys();
+        void this._setupHotkeys();
 
         const optionsPageUrl = (
             typeof manifest.options_ui === 'object' &&
@@ -114,7 +114,7 @@ class DisplayController {
                         const result = customHandler(e);
                         if (typeof result !== 'undefined') { return; }
                     }
-                    this._api.commandExec(command, {mode: e.ctrlKey ? 'newTab' : 'existingOrNewTab'});
+                    void this._api.commandExec(command, {mode: e.ctrlKey ? 'newTab' : 'existingOrNewTab'});
                     e.preventDefault();
                 };
                 /**
@@ -122,7 +122,7 @@ class DisplayController {
                  */
                 const onAuxClick = (e) => {
                     if (e.button !== 1) { return; }
-                    this._api.commandExec(command, {mode: 'newTab'});
+                    void this._api.commandExec(command, {mode: 'newTab'});
                     e.preventDefault();
                 };
                 node.addEventListener('click', onClick, false);
@@ -191,8 +191,8 @@ class DisplayController {
             toggle.checked = extensionEnabled;
             toggle.addEventListener('change', onToggleChanged, false);
         }
-        this._updateDictionariesEnabledWarnings(options);
-        this._updatePermissionsWarnings(options);
+        void this._updateDictionariesEnabledWarnings(options);
+        void this._updatePermissionsWarnings(options);
     }
 
     /** */
@@ -240,7 +240,7 @@ class DisplayController {
         const node = /** @type {HTMLInputElement} */ (event.currentTarget);
         const value = Number.parseInt(node.value, 10);
         if (typeof value === 'number' && Number.isFinite(value) && value >= 0 && value <= /** @type {import('settings').Options} */ (this._optionsFull).profiles.length) {
-            this._setPrimaryProfileIndex(value);
+            void this._setPrimaryProfileIndex(value);
         }
     }
 
@@ -307,8 +307,8 @@ class DisplayController {
 }
 
 await Application.main(true, async (application) => {
-    application.api.logIndicatorClear();
+    void application.api.logIndicatorClear();
 
     const displayController = new DisplayController(application.api);
-    displayController.prepare();
+    await displayController.prepare();
 });
diff --git a/ext/js/pages/common/extension-content-controller.js b/ext/js/pages/common/extension-content-controller.js
index 5b968d0c..be79ae8b 100644
--- a/ext/js/pages/common/extension-content-controller.js
+++ b/ext/js/pages/common/extension-content-controller.js
@@ -23,7 +23,7 @@ export class ExtensionContentController {
     prepare() {
         this._prepareSpecialUrls();
         this._prepareExtensionIdExamples();
-        this._prepareEnvironmentInfo();
+        void this._prepareEnvironmentInfo();
     }
 
     // Private
@@ -93,7 +93,7 @@ export class ExtensionContentController {
                     const {specialUrl} = element.dataset;
                     if (typeof specialUrl !== 'string') { return; }
                     e.preventDefault();
-                    this._createTab(specialUrl, true);
+                    void this._createTab(specialUrl, true);
                 }
                 break;
         }
diff --git a/ext/js/pages/info-main.js b/ext/js/pages/info-main.js
index dda1c4e2..c0e37261 100644
--- a/ext/js/pages/info-main.js
+++ b/ext/js/pages/info-main.js
@@ -148,8 +148,8 @@ await Application.main(true, async (application) => {
     languageElement.textContent = `${language}`;
     userAgentElement.textContent = userAgent;
 
-    showAnkiConnectInfo(application.api);
-    showDictionaryInfo(application.api);
+    void showAnkiConnectInfo(application.api);
+    void showDictionaryInfo(application.api);
 
     const settingsController = new SettingsController(application);
     await settingsController.prepare();
diff --git a/ext/js/pages/permissions-main.js b/ext/js/pages/permissions-main.js
index 40dbceb2..39a79620 100644
--- a/ext/js/pages/permissions-main.js
+++ b/ext/js/pages/permissions-main.js
@@ -95,7 +95,7 @@ await Application.main(true, async (application) => {
 
     setupPermissionsToggles();
 
-    setupEnvironmentInfo(application.api);
+    void setupEnvironmentInfo(application.api);
 
     /** @type {HTMLInputElement} */
     const permissionCheckbox1 = querySelectorNotNull(document, '#permission-checkbox-allow-in-private-windows');
@@ -122,13 +122,13 @@ await Application.main(true, async (application) => {
     await settingsController.prepare();
 
     const permissionsToggleController = new PermissionsToggleController(settingsController);
-    permissionsToggleController.prepare();
+    void permissionsToggleController.prepare();
 
     const permissionsOriginController = new PermissionsOriginController(settingsController);
-    permissionsOriginController.prepare();
+    void permissionsOriginController.prepare();
 
     const persistentStorageController = new PersistentStorageController(application);
-    persistentStorageController.prepare();
+    void persistentStorageController.prepare();
 
     await promiseTimeout(100);
 
diff --git a/ext/js/pages/settings/anki-controller.js b/ext/js/pages/settings/anki-controller.js
index ecee1788..edd40516 100644
--- a/ext/js/pages/settings/anki-controller.js
+++ b/ext/js/pages/settings/anki-controller.js
@@ -110,7 +110,7 @@ export class AnkiController {
         ankiApiKeyInput.addEventListener('focus', this._onApiKeyInputFocus.bind(this));
         ankiApiKeyInput.addEventListener('blur', this._onApiKeyInputBlur.bind(this));
 
-        const onAnkiSettingChanged = () => { this._updateOptions(); };
+        const onAnkiSettingChanged = () => { void this._updateOptions(); };
         const nodes = [ankiApiKeyInput, ...document.querySelectorAll('[data-setting="anki.enable"]')];
         for (const node of nodes) {
             node.addEventListener('settingChanged', onAnkiSettingChanged);
@@ -128,7 +128,7 @@ export class AnkiController {
         if (promise === null) {
             promise = this._getAnkiData();
             this._getAnkiDataPromise = promise;
-            promise.finally(() => { this._getAnkiDataPromise = null; });
+            void promise.finally(() => { this._getAnkiDataPromise = null; });
         }
         return promise;
     }
@@ -161,7 +161,7 @@ export class AnkiController {
     /**
      * @param {import('settings-controller').EventArgument<'optionsChanged'>} details
      */
-    async _onOptionsChanged({options: {anki}}) {
+    _onOptionsChanged({options: {anki}}) {
         /** @type {?string} */
         let apiKey = anki.apiKey;
         if (apiKey === '') { apiKey = null; }
@@ -187,7 +187,7 @@ export class AnkiController {
         this._ankiConnect.enabled = typeof value === 'boolean' && value;
 
         for (const cardController of this._selectorObserver.datas()) {
-            cardController.updateAnkiState();
+            void cardController.updateAnkiState();
         }
     }
 
@@ -219,7 +219,7 @@ export class AnkiController {
 
         const normalizedMode = this._normalizeAnkiNoteGuiMode(mode);
         if (normalizedMode === null) { return; }
-        this._testAnkiNoteViewerSafe(normalizedMode);
+        void this._testAnkiNoteViewerSafe(normalizedMode);
     }
 
     /**
@@ -258,7 +258,7 @@ export class AnkiController {
      */
     _createCardController(node) {
         const cardController = new AnkiCardController(this._settingsController, this, /** @type {HTMLElement} */ (node));
-        cardController.prepare();
+        void cardController.prepare();
         return cardController;
     }
 
@@ -588,7 +588,7 @@ class AnkiCardController {
      */
     _onCardDeckChange(e) {
         const node = /** @type {HTMLSelectElement} */ (e.currentTarget);
-        this._setDeck(node.value);
+        void this._setDeck(node.value);
     }
 
     /**
@@ -596,7 +596,7 @@ class AnkiCardController {
      */
     _onCardModelChange(e) {
         const node = /** @type {HTMLSelectElement} */ (e.currentTarget);
-        this._setModel(node.value);
+        void this._setModel(node.value);
     }
 
     /**
@@ -605,7 +605,7 @@ class AnkiCardController {
      */
     _onFieldChange(index, e) {
         const node = /** @type {HTMLInputElement} */ (e.currentTarget);
-        this._validateFieldPermissions(node, index, true);
+        void this._validateFieldPermissions(node, index, true);
         this._validateField(node, index);
     }
 
@@ -624,7 +624,7 @@ class AnkiCardController {
      */
     _onFieldSettingChanged(index, e) {
         const node = /** @type {HTMLInputElement} */ (e.currentTarget);
-        this._validateFieldPermissions(node, index, false);
+        void this._validateFieldPermissions(node, index, false);
     }
 
     /**
@@ -731,7 +731,7 @@ class AnkiCardController {
             const inputField = querySelectorNotNull(content, '.anki-card-field-value');
             inputField.value = fieldValue;
             inputField.dataset.setting = ObjectPropertyAccessor.getPathString(['anki', this._optionsType, 'fields', fieldName]);
-            this._validateFieldPermissions(inputField, index, false);
+            void this._validateFieldPermissions(inputField, index, false);
 
             this._fieldEventListeners.addEventListener(inputField, 'change', this._onFieldChange.bind(this, index), false);
             this._fieldEventListeners.addEventListener(inputField, 'input', this._onFieldInput.bind(this, index), false);
@@ -769,7 +769,7 @@ class AnkiCardController {
             container.appendChild(totalFragment);
         }
 
-        this._validateFields();
+        void this._validateFields();
     }
 
     /** */
diff --git a/ext/js/pages/settings/anki-templates-controller.js b/ext/js/pages/settings/anki-templates-controller.js
index 332102cf..a0a6bd6c 100644
--- a/ext/js/pages/settings/anki-templates-controller.js
+++ b/ext/js/pages/settings/anki-templates-controller.js
@@ -156,7 +156,7 @@ export class AnkiTemplatesController {
     /** */
     _onValidateCompile() {
         if (this._compileResultInfo === null) { return; }
-        this._validate(this._compileResultInfo, '{expression}', 'term-kanji', false, true);
+        void this._validate(this._compileResultInfo, '{expression}', 'term-kanji', false, true);
     }
 
     /**
@@ -169,7 +169,7 @@ export class AnkiTemplatesController {
         const infoNode = /** @type {HTMLElement} */ (this._renderResult);
         infoNode.hidden = true;
         this._cachedDictionaryEntryText = null;
-        this._validate(infoNode, field, 'term-kanji', true, false);
+        void this._validate(infoNode, field, 'term-kanji', true, false);
     }
 
     /**
diff --git a/ext/js/pages/settings/audio-controller.js b/ext/js/pages/settings/audio-controller.js
index 5b597d33..ab7e377c 100644
--- a/ext/js/pages/settings/audio-controller.js
+++ b/ext/js/pages/settings/audio-controller.js
@@ -134,7 +134,7 @@ export class AudioController extends EventDispatcher {
 
     /** */
     _onAddAudioSource() {
-        this._addAudioSource();
+        void this._addAudioSource();
     }
 
     /** */
@@ -145,7 +145,7 @@ export class AudioController extends EventDispatcher {
             const voiceUri = input.dataset.voice;
             const audio = this._audioSystem.createTextToSpeechAudio(text, typeof voiceUri === 'string' ? voiceUri : '');
             audio.volume = 1;
-            audio.play();
+            void audio.play();
         } catch (e) {
             // NOP
         }
@@ -352,7 +352,7 @@ class AudioSourceEntry {
         const element = /** @type {HTMLSelectElement} */ (e.currentTarget);
         const value = this._normalizeAudioSourceType(element.value);
         if (value === null) { return; }
-        this._setType(value);
+        void this._setType(value);
     }
 
     /**
@@ -360,7 +360,7 @@ class AudioSourceEntry {
      */
     _onUrlInputChange(e) {
         const element = /** @type {HTMLInputElement} */ (e.currentTarget);
-        this._setUrl(element.value);
+        void this._setUrl(element.value);
     }
 
     /**
@@ -368,7 +368,7 @@ class AudioSourceEntry {
      */
     _onVoiceSelectChange(e) {
         const element = /** @type {HTMLSelectElement} */ (e.currentTarget);
-        this._setVoice(element.value);
+        void this._setVoice(element.value);
     }
 
     /**
@@ -403,7 +403,7 @@ class AudioSourceEntry {
                 this._showHelp(this._type);
                 break;
             case 'remove':
-                this._parent.removeSource(this);
+                void this._parent.removeSource(this);
                 break;
         }
     }
diff --git a/ext/js/pages/settings/backup-controller.js b/ext/js/pages/settings/backup-controller.js
index 18991140..2a0706e4 100644
--- a/ext/js/pages/settings/backup-controller.js
+++ b/ext/js/pages/settings/backup-controller.js
@@ -642,7 +642,7 @@ export class BackupController {
         await Dexie.import(file, {
             progressCallback: this._databaseImportProgressCallback.bind(this)
         });
-        this._settingsController.application.api.triggerDatabaseUpdated('dictionary', 'import');
+        void this._settingsController.application.api.triggerDatabaseUpdated('dictionary', 'import');
         this._settingsController.application.triggerStorageChanged();
     }
 
diff --git a/ext/js/pages/settings/collapsible-dictionary-controller.js b/ext/js/pages/settings/collapsible-dictionary-controller.js
index 62f84b96..f2a03b5c 100644
--- a/ext/js/pages/settings/collapsible-dictionary-controller.js
+++ b/ext/js/pages/settings/collapsible-dictionary-controller.js
@@ -99,7 +99,7 @@ export class CollapsibleDictionaryController {
 
     /** */
     _onDefinitionsCollapsibleChange() {
-        this._updateAllSelectFresh();
+        void this._updateAllSelectFresh();
     }
 
     /**
@@ -109,7 +109,7 @@ export class CollapsibleDictionaryController {
         const {value} = /** @type {HTMLSelectElement} */ (e.currentTarget);
         const value2 = this._normalizeDictionaryDefinitionsCollapsible(value);
         if (value2 === null) { return; }
-        this._setDefinitionsCollapsibleAll(value2);
+        void this._setDefinitionsCollapsibleAll(value2);
     }
 
     /** */
diff --git a/ext/js/pages/settings/dictionary-controller.js b/ext/js/pages/settings/dictionary-controller.js
index 66ff0923..a6760268 100644
--- a/ext/js/pages/settings/dictionary-controller.js
+++ b/ext/js/pages/settings/dictionary-controller.js
@@ -149,7 +149,7 @@ class DictionaryEntry {
     _onEnabledChanged(e) {
         const {detail: {value}} = e;
         this._titleContainer.dataset.enabled = `${value}`;
-        this._dictionaryController.updateDictionariesEnabled();
+        void this._dictionaryController.updateDictionariesEnabled();
     }
 
     /** */
@@ -255,7 +255,7 @@ class DictionaryEntry {
      * @param {number} offset
      */
     _move(offset) {
-        this._dictionaryController.moveDictionaryOptions(this._index, this._index + offset);
+        void this._dictionaryController.moveDictionaryOptions(this._index, this._index + offset);
     }
 
     /**
@@ -598,7 +598,7 @@ export class DictionaryController {
     _onOptionsChanged({options}) {
         this._updateDictionariesEnabledWarnings(options);
         if (this._dictionaries !== null) {
-            this._updateEntries();
+            void this._updateEntries();
         }
     }
 
@@ -620,7 +620,7 @@ export class DictionaryController {
         const allCheckbox = /** @type {HTMLInputElement} */ (this._allCheckbox);
         const value = allCheckbox.checked;
         allCheckbox.checked = !value;
-        this._setAllDictionariesEnabled(value);
+        void this._setAllDictionariesEnabled(value);
     }
 
     /** */
@@ -718,7 +718,7 @@ export class DictionaryController {
         if (typeof title !== 'string') { return; }
         delete modal.node.dataset.dictionaryTitle;
 
-        this._deleteDictionary(title);
+        void this._deleteDictionary(title);
     }
 
     /**
@@ -726,7 +726,7 @@ export class DictionaryController {
      */
     _onCheckIntegrityButtonClick(e) {
         e.preventDefault();
-        this._checkIntegrity();
+        void this._checkIntegrity();
     }
 
     /** */
@@ -743,7 +743,7 @@ export class DictionaryController {
 
         if (!Number.isFinite(target) || !Number.isFinite(indexNumber) || indexNumber === target) { return; }
 
-        this.moveDictionaryOptions(indexNumber, target);
+        void this.moveDictionaryOptions(indexNumber, target);
     }
 
     /**
@@ -916,7 +916,7 @@ export class DictionaryController {
      */
     async _deleteDictionaryInternal(dictionaryTitle, onProgress) {
         await new DictionaryWorker().deleteDictionary(dictionaryTitle, onProgress);
-        this._settingsController.application.api.triggerDatabaseUpdated('dictionary', 'delete');
+        void this._settingsController.application.api.triggerDatabaseUpdated('dictionary', 'delete');
     }
 
     /**
diff --git a/ext/js/pages/settings/dictionary-import-controller.js b/ext/js/pages/settings/dictionary-import-controller.js
index f44ef380..13766d80 100644
--- a/ext/js/pages/settings/dictionary-import-controller.js
+++ b/ext/js/pages/settings/dictionary-import-controller.js
@@ -64,7 +64,7 @@ export class DictionaryImportController {
     }
 
     /** */
-    async prepare() {
+    prepare() {
         this._purgeConfirmModal = this._modalController.getModal('dictionary-confirm-delete-all');
 
         this._purgeButton.addEventListener('click', this._onPurgeButtonClick.bind(this), false);
@@ -94,7 +94,7 @@ export class DictionaryImportController {
     _onPurgeConfirmButtonClick(e) {
         e.preventDefault();
         /** @type {import('./modal.js').Modal} */ (this._purgeConfirmModal).setVisible(false);
-        this._purgeDatabase();
+        void this._purgeDatabase();
     }
 
     /**
@@ -106,7 +106,7 @@ export class DictionaryImportController {
         if (files === null) { return; }
         const files2 = [...files];
         node.value = '';
-        this._importDictionaries(files2);
+        void this._importDictionaries(files2);
     }
 
     /** */
@@ -235,7 +235,7 @@ export class DictionaryImportController {
     async _importDictionary(file, importDetails, onProgress) {
         const archiveContent = await this._readFile(file);
         const {result, errors} = await new DictionaryWorker().importDictionary(archiveContent, importDetails, onProgress);
-        this._settingsController.application.api.triggerDatabaseUpdated('dictionary', 'import');
+        void this._settingsController.application.api.triggerDatabaseUpdated('dictionary', 'import');
         const errors2 = await this._addDictionarySettings(result.sequenced, result.title);
 
         if (errors.length > 0) {
diff --git a/ext/js/pages/settings/extension-keyboard-shortcuts-controller.js b/ext/js/pages/settings/extension-keyboard-shortcuts-controller.js
index b9d107ae..1f55f391 100644
--- a/ext/js/pages/settings/extension-keyboard-shortcuts-controller.js
+++ b/ext/js/pages/settings/extension-keyboard-shortcuts-controller.js
@@ -133,7 +133,7 @@ export class ExtensionKeyboardShortcutController {
      */
     _onResetClick(e) {
         e.preventDefault();
-        this._resetAllCommands();
+        void this._resetAllCommands();
     }
 
     /**
@@ -141,7 +141,7 @@ export class ExtensionKeyboardShortcutController {
      */
     _onClearClick(e) {
         e.preventDefault();
-        this._clearAllCommands();
+        void this._clearAllCommands();
     }
 
     /**
@@ -317,7 +317,7 @@ class ExtensionKeyboardShortcutHotkeyEntry {
      */
     _onInputFieldChange(e) {
         const {key, modifiers} = e;
-        this._tryUpdateInput(key, modifiers, false);
+        void this._tryUpdateInput(key, modifiers, false);
     }
 
     /** */
@@ -331,10 +331,10 @@ class ExtensionKeyboardShortcutHotkeyEntry {
     _onMenuClose(e) {
         switch (e.detail.action) {
             case 'clearInput':
-                this._tryUpdateInput(null, [], true);
+                void this._tryUpdateInput(null, [], true);
                 break;
             case 'resetInput':
-                this._resetInput();
+                void this._resetInput();
                 break;
         }
     }
diff --git a/ext/js/pages/settings/generic-setting-controller.js b/ext/js/pages/settings/generic-setting-controller.js
index 7c082a96..54d87f8d 100644
--- a/ext/js/pages/settings/generic-setting-controller.js
+++ b/ext/js/pages/settings/generic-setting-controller.js
@@ -66,7 +66,7 @@ export class GenericSettingController {
 
     /** */
     _onOptionsChanged() {
-        this._dataBinder.refresh();
+        void this._dataBinder.refresh();
     }
 
     /**
diff --git a/ext/js/pages/settings/keyboard-shortcuts-controller.js b/ext/js/pages/settings/keyboard-shortcuts-controller.js
index 0a01b836..b1ea6bb0 100644
--- a/ext/js/pages/settings/keyboard-shortcuts-controller.js
+++ b/ext/js/pages/settings/keyboard-shortcuts-controller.js
@@ -191,7 +191,7 @@ export class KeyboardShortcutController {
      */
     _onAddClick(e) {
         e.preventDefault();
-        this._addNewEntry();
+        void this._addNewEntry();
     }
 
     /**
@@ -199,7 +199,7 @@ export class KeyboardShortcutController {
      */
     _onResetClick(e) {
         e.preventDefault();
-        this._reset();
+        void this._reset();
     }
 
     /** */
@@ -350,16 +350,16 @@ class KeyboardShortcutHotkeyEntry {
     _onMenuClose(e) {
         switch (e.detail.action) {
             case 'delete':
-                this._delete();
+                void this._delete();
                 break;
             case 'clearInputs':
                 /** @type {KeyboardMouseInputField} */ (this._inputField).clearInputs();
                 break;
             case 'resetInput':
-                this._resetInput();
+                void this._resetInput();
                 break;
             case 'resetArgument':
-                this._resetArgument();
+                void this._resetArgument();
                 break;
         }
     }
@@ -404,7 +404,7 @@ class KeyboardShortcutHotkeyEntry {
             if (modifier2 === null) { continue; }
             modifiers2.push(modifier2);
         }
-        this._setKeyAndModifiers(key, modifiers2);
+        void this._setKeyAndModifiers(key, modifiers2);
     }
 
     /**
@@ -414,7 +414,7 @@ class KeyboardShortcutHotkeyEntry {
         const node = /** @type {HTMLInputElement} */ (e.currentTarget);
         const scope = this._normalizeScope(node.dataset.scope);
         if (scope === null) { return; }
-        this._setScopeEnabled(scope, node.checked);
+        void this._setScopeEnabled(scope, node.checked);
     }
 
     /**
@@ -423,7 +423,7 @@ class KeyboardShortcutHotkeyEntry {
     _onActionSelectChange(e) {
         const node = /** @type {HTMLSelectElement} */ (e.currentTarget);
         const value = node.value;
-        this._setAction(value);
+        void this._setAction(value);
     }
 
     /**
@@ -438,12 +438,12 @@ class KeyboardShortcutHotkeyEntry {
                 value = `${convertElementValueToNumber(value, node)}`;
                 break;
         }
-        this._setArgument(value);
+        void this._setArgument(value);
     }
 
     /** */
     async _delete() {
-        this._parent.deleteEntry(this._index);
+        void this._parent.deleteEntry(this._index);
     }
 
     /**
@@ -607,7 +607,7 @@ class KeyboardShortcutHotkeyEntry {
             this._setArgumentInputValue(node, value);
         }
 
-        this._updateArgumentInputValidity();
+        void this._updateArgumentInputValidity();
 
         await this._modifyProfileSettings([{
             action: 'set',
@@ -702,7 +702,7 @@ class KeyboardShortcutHotkeyEntry {
             if (inputNode !== null) {
                 this._setArgumentInputValue(inputNode, argument);
                 this._argumentInput = inputNode;
-                this._updateArgumentInputValidity();
+                void this._updateArgumentInputValidity();
                 this._argumentEventListeners.addEventListener(inputNode, 'change', this._onArgumentValueChange.bind(this, template), false);
             }
             if (this._argumentContainer !== null) {
diff --git a/ext/js/pages/settings/mecab-controller.js b/ext/js/pages/settings/mecab-controller.js
index ba2f6166..34c4045f 100644
--- a/ext/js/pages/settings/mecab-controller.js
+++ b/ext/js/pages/settings/mecab-controller.js
@@ -46,7 +46,7 @@ export class MecabController {
      */
     _onTestButtonClick(e) {
         e.preventDefault();
-        this._testMecab();
+        void this._testMecab();
     }
 
     /** */
diff --git a/ext/js/pages/settings/nested-popups-controller.js b/ext/js/pages/settings/nested-popups-controller.js
index 077b1a66..fe0696d6 100644
--- a/ext/js/pages/settings/nested-popups-controller.js
+++ b/ext/js/pages/settings/nested-popups-controller.js
@@ -63,7 +63,7 @@ export class NestedPopupsController {
         const node = /** @type {HTMLInputElement} */ (e.currentTarget);
         const value = node.checked;
         if (value && this._popupNestingMaxDepth > 0) { return; }
-        this._setPopupNestingMaxDepth(value ? 1 : 0);
+        void this._setPopupNestingMaxDepth(value ? 1 : 0);
     }
 
     /**
@@ -72,7 +72,7 @@ export class NestedPopupsController {
     _onNestedPopupsCountChange(e) {
         const node = /** @type {HTMLInputElement} */ (e.currentTarget);
         const value = Math.max(1, convertElementValueToNumber(node.value, node));
-        this._setPopupNestingMaxDepth(value);
+        void this._setPopupNestingMaxDepth(value);
     }
 
     /**
diff --git a/ext/js/pages/settings/permissions-origin-controller.js b/ext/js/pages/settings/permissions-origin-controller.js
index 9447e3cc..ec04e81e 100644
--- a/ext/js/pages/settings/permissions-origin-controller.js
+++ b/ext/js/pages/settings/permissions-origin-controller.js
@@ -114,19 +114,19 @@ export class PermissionsOriginController {
 
         const {origin} = node.dataset;
         if (typeof origin !== 'string') { return; }
-        this._setOriginPermissionEnabled(origin, value);
+        void this._setOriginPermissionEnabled(origin, value);
     }
 
     /**
      * @param {string} origin
      */
     _onOriginMenuClose(origin) {
-        this._setOriginPermissionEnabled(origin, false);
+        void this._setOriginPermissionEnabled(origin, false);
     }
 
     /** */
     _onAddButtonClick() {
-        this._addOrigin();
+        void this._addOrigin();
     }
 
     /** */
diff --git a/ext/js/pages/settings/permissions-toggle-controller.js b/ext/js/pages/settings/permissions-toggle-controller.js
index 25204dce..e094092c 100644
--- a/ext/js/pages/settings/permissions-toggle-controller.js
+++ b/ext/js/pages/settings/permissions-toggle-controller.js
@@ -69,7 +69,7 @@ export class PermissionsToggleController {
             }
             toggle.checked = !!value;
         }
-        this._updateValidity();
+        void this._updateValidity();
     }
 
     /**
diff --git a/ext/js/pages/settings/persistent-storage-controller.js b/ext/js/pages/settings/persistent-storage-controller.js
index 8b7726dd..e0ff75ee 100644
--- a/ext/js/pages/settings/persistent-storage-controller.js
+++ b/ext/js/pages/settings/persistent-storage-controller.js
@@ -70,7 +70,7 @@ export class PersistentStorageController {
         const node = /** @type {HTMLInputElement} */ (e.currentTarget);
         if (node.checked) {
             node.checked = false;
-            this._attemptPersistStorage();
+            void this._attemptPersistStorage();
         } else {
             node.checked = true;
         }
diff --git a/ext/js/pages/settings/popup-preview-controller.js b/ext/js/pages/settings/popup-preview-controller.js
index bd335460..8361809d 100644
--- a/ext/js/pages/settings/popup-preview-controller.js
+++ b/ext/js/pages/settings/popup-preview-controller.js
@@ -38,7 +38,7 @@ export class PopupPreviewController {
     }
 
     /** */
-    async prepare() {
+    prepare() {
         if (new URLSearchParams(location.search).get('popup-preview') === 'false') { return; }
 
         this._customCss.addEventListener('input', this._onCustomCssChange.bind(this), false);
diff --git a/ext/js/pages/settings/popup-preview-frame.js b/ext/js/pages/settings/popup-preview-frame.js
index d3e21641..8d881cc6 100644
--- a/ext/js/pages/settings/popup-preview-frame.js
+++ b/ext/js/pages/settings/popup-preview-frame.js
@@ -89,7 +89,7 @@ export class PopupPreviewFrame {
 
         this._languageSummaries = await this._application.api.getLanguageSummaries();
         const options = await this._application.api.optionsGet({current: true});
-        this._onOptionsChanged({options, optionsContext: {current: true}});
+        void this._onOptionsChanged({options, optionsContext: {current: true}});
 
         // Overwrite frontend
         this._frontend = new Frontend({
@@ -115,7 +115,7 @@ export class PopupPreviewFrame {
         }
 
         // Update search
-        this._updateSearch();
+        void this._updateSearch();
     }
 
     // Private
@@ -181,7 +181,7 @@ export class PopupPreviewFrame {
             this._themeChangeTimeout = null;
             const popup = /** @type {Frontend} */ (this._frontend).popup;
             if (popup === null) { return; }
-            popup.updateTheme();
+            void popup.updateTheme();
         }, 300);
     }
 
@@ -229,7 +229,7 @@ export class PopupPreviewFrame {
 
         this._exampleText.textContent = text;
         if (this._frontend === null) { return; }
-        this._updateSearch();
+        void this._updateSearch();
     }
 
     /**
@@ -249,7 +249,7 @@ export class PopupPreviewFrame {
         if (this._frontend === null) { return; }
         const popup = this._frontend.popup;
         if (popup === null) { return; }
-        popup.setCustomCss(css);
+        void popup.setCustomCss(css);
     }
 
     /**
@@ -259,7 +259,7 @@ export class PopupPreviewFrame {
         if (this._frontend === null) { return; }
         const popup = this._frontend.popup;
         if (popup === null) { return; }
-        popup.setCustomOuterCss(css, false);
+        void popup.setCustomOuterCss(css, false);
     }
 
     /**
diff --git a/ext/js/pages/settings/popup-window-controller.js b/ext/js/pages/settings/popup-window-controller.js
index 62879f3b..ddf2eef6 100644
--- a/ext/js/pages/settings/popup-window-controller.js
+++ b/ext/js/pages/settings/popup-window-controller.js
@@ -41,7 +41,7 @@ export class PopupWindowController {
      */
     _onTestWindowOpenLinkClick(e) {
         e.preventDefault();
-        this._testWindowOpen();
+        void this._testWindowOpen();
     }
 
     /** */
diff --git a/ext/js/pages/settings/profile-conditions-ui.js b/ext/js/pages/settings/profile-conditions-ui.js
index d2bf03bf..8f53232a 100644
--- a/ext/js/pages/settings/profile-conditions-ui.js
+++ b/ext/js/pages/settings/profile-conditions-ui.js
@@ -266,7 +266,7 @@ export class ProfileConditionsUI extends EventDispatcher {
             this._children[i].index = i;
         }
 
-        this.settingsController.modifyGlobalSettings([{
+        void this.settingsController.modifyGlobalSettings([{
             action: 'splice',
             path: this.getPath('conditionGroups'),
             start: index,
@@ -333,7 +333,7 @@ export class ProfileConditionsUI extends EventDispatcher {
 
         this._addConditionGroup(conditionGroup, index);
 
-        this.settingsController.modifyGlobalSettings([{
+        void this.settingsController.modifyGlobalSettings([{
             action: 'splice',
             path: this.getPath('conditionGroups'),
             start: index,
@@ -543,7 +543,7 @@ class ProfileConditionGroupUI {
             this._children[i].index = i;
         }
 
-        this.settingsController.modifyGlobalSettings([{
+        void this.settingsController.modifyGlobalSettings([{
             action: 'splice',
             path: this.getPath('conditions'),
             start: index,
@@ -581,7 +581,7 @@ class ProfileConditionGroupUI {
 
         this._addCondition(condition, index);
 
-        this.settingsController.modifyGlobalSettings([{
+        void this.settingsController.modifyGlobalSettings([{
             action: 'splice',
             path: this.getPath('conditions'),
             start: index,
@@ -714,7 +714,7 @@ class ProfileConditionUI {
         const element = /** @type {HTMLSelectElement} */ (e.currentTarget);
         const type = ProfileConditionsUI.normalizeProfileConditionType(element.value);
         if (type === null) { return; }
-        this._setType(type);
+        void this._setType(type);
     }
 
     /**
@@ -725,7 +725,7 @@ class ProfileConditionUI {
         const type = ProfileConditionsUI.normalizeProfileConditionType(this._typeInput.value);
         if (type === null) { return; }
         const operator = element.value;
-        this._setOperator(type, operator);
+        void this._setOperator(type, operator);
     }
 
     /**
@@ -740,7 +740,7 @@ class ProfileConditionUI {
         if (okay) {
             const normalizedValue = this._normalizeValue(value, normalize);
             node.value = normalizedValue;
-            this.settingsController.setGlobalSetting(this.getPath('value'), normalizedValue);
+            void this.settingsController.setGlobalSetting(this.getPath('value'), normalizedValue);
         }
     }
 
@@ -754,7 +754,7 @@ class ProfileConditionUI {
         this._value = modifiers;
         if (okay) {
             const normalizedValue = this._normalizeValue(modifiers, normalize);
-            this.settingsController.setGlobalSetting(this.getPath('value'), normalizedValue);
+            void this.settingsController.setGlobalSetting(this.getPath('value'), normalizedValue);
         }
     }
 
@@ -782,7 +782,7 @@ class ProfileConditionUI {
                 this._parent.removeSelf();
                 break;
             case 'resetValue':
-                this._resetValue();
+                void this._resetValue();
                 break;
         }
     }
diff --git a/ext/js/pages/settings/profile-controller.js b/ext/js/pages/settings/profile-controller.js
index a82a4b4e..9d4ed33b 100644
--- a/ext/js/pages/settings/profile-controller.js
+++ b/ext/js/pages/settings/profile-controller.js
@@ -98,7 +98,7 @@ export class ProfileController {
 
         this._profileConditionsUI.on('conditionGroupCountChanged', this._onConditionGroupCountChanged.bind(this));
         this._settingsController.on('optionsChanged', this._onOptionsChanged.bind(this));
-        this._onOptionsChanged();
+        void this._onOptionsChanged();
     }
 
     /**
@@ -376,7 +376,7 @@ export class ProfileController {
 
         this._profileConditionsUI.cleanup();
         this._profileConditionsIndex = profileIndex;
-        this._profileConditionsUI.prepare(profileIndex);
+        void this._profileConditionsUI.prepare(profileIndex);
         if (this._profileConditionsProfileName !== null) {
             this._profileConditionsProfileName.textContent = profile.name;
         }
@@ -403,7 +403,7 @@ export class ProfileController {
         this._profileConditionsUI.cleanup();
         const conditionsProfile = this._getProfile(this._profileConditionsIndex !== null ? this._profileConditionsIndex : settingsProfileIndex);
         if (conditionsProfile !== null) {
-            this._profileConditionsUI.prepare(settingsProfileIndex);
+            void this._profileConditionsUI.prepare(settingsProfileIndex);
         }
 
         // Udpate profile entries
@@ -425,7 +425,7 @@ export class ProfileController {
         const element = /** @type {HTMLSelectElement} */ (e.currentTarget);
         const value = this._tryGetValidProfileIndex(element.value);
         if (value === null) { return; }
-        this.setDefaultProfile(value);
+        void this.setDefaultProfile(value);
     }
 
     /**
@@ -440,7 +440,7 @@ export class ProfileController {
 
     /** */
     _onAdd() {
-        this.duplicateProfile(this._settingsController.profileIndex);
+        void this.duplicateProfile(this._settingsController.profileIndex);
     }
 
     /** */
@@ -454,7 +454,7 @@ export class ProfileController {
         const validProfileIndex = this._tryGetValidProfileIndex(profileIndex);
         if (validProfileIndex === null) { return; }
 
-        this.deleteProfile(validProfileIndex);
+        void this.deleteProfile(validProfileIndex);
     }
 
     /** */
@@ -471,7 +471,7 @@ export class ProfileController {
         const sourceProfileIndex = this._tryGetValidProfileIndex(/** @type {HTMLSelectElement} */ (this._profileCopySourceSelect).value);
         if (sourceProfileIndex === null) { return; }
 
-        this.copyProfile(sourceProfileIndex, validDestinationProfileIndex);
+        void this.copyProfile(sourceProfileIndex, validDestinationProfileIndex);
     }
 
     /**
@@ -738,7 +738,7 @@ class ProfileEntry {
     _onIsDefaultRadioChange(e) {
         const element = /** @type {HTMLInputElement} */ (e.currentTarget);
         if (!element.checked) { return; }
-        this._profileController.setDefaultProfile(this._index);
+        void this._profileController.setDefaultProfile(this._index);
     }
 
     /**
@@ -747,7 +747,7 @@ class ProfileEntry {
     _onNameInputInput(e) {
         const element = /** @type {HTMLInputElement} */ (e.currentTarget);
         const name = element.value;
-        this._profileController.setProfileName(this._index, name);
+        void this._profileController.setProfileName(this._index, name);
     }
 
     /** */
@@ -773,10 +773,10 @@ class ProfileEntry {
     _onMenuClose(e) {
         switch (e.detail.action) {
             case 'moveUp':
-                this._profileController.moveProfile(this._index, -1);
+                void this._profileController.moveProfile(this._index, -1);
                 break;
             case 'moveDown':
-                this._profileController.moveProfile(this._index, 1);
+                void this._profileController.moveProfile(this._index, 1);
                 break;
             case 'copyFrom':
                 this._profileController.openCopyProfileModal(this._index);
@@ -785,7 +785,7 @@ class ProfileEntry {
                 this._profileController.openProfileConditionsModal(this._index);
                 break;
             case 'duplicate':
-                this._profileController.duplicateProfile(this._index);
+                void this._profileController.duplicateProfile(this._index);
                 break;
             case 'delete':
                 this._profileController.openDeleteProfileModal(this._index);
diff --git a/ext/js/pages/settings/recommended-permissions-controller.js b/ext/js/pages/settings/recommended-permissions-controller.js
index b7bb1ea8..8aff51c4 100644
--- a/ext/js/pages/settings/recommended-permissions-controller.js
+++ b/ext/js/pages/settings/recommended-permissions-controller.js
@@ -73,7 +73,7 @@ export class RecommendedPermissionsController {
 
         const {origin} = node.dataset;
         if (typeof origin !== 'string') { return; }
-        this._setOriginPermissionEnabled(origin, value);
+        void this._setOriginPermissionEnabled(origin, value);
     }
 
     /** */
diff --git a/ext/js/pages/settings/scan-inputs-controller.js b/ext/js/pages/settings/scan-inputs-controller.js
index 144eae9f..fcaad589 100644
--- a/ext/js/pages/settings/scan-inputs-controller.js
+++ b/ext/js/pages/settings/scan-inputs-controller.js
@@ -51,7 +51,7 @@ export class ScanInputsController {
         this._settingsController.on('scanInputsChanged', this._onScanInputsChanged.bind(this));
         this._settingsController.on('optionsChanged', this._onOptionsChanged.bind(this));
 
-        this.refresh();
+        await this.refresh();
     }
 
     /**
@@ -67,7 +67,7 @@ export class ScanInputsController {
             this._entries[i].index = i;
         }
         this._updateCounts();
-        this._modifyProfileSettings([{
+        void this._modifyProfileSettings([{
             action: 'splice',
             path: 'scanning.inputs',
             start: index,
@@ -113,7 +113,7 @@ export class ScanInputsController {
      */
     _onScanInputsChanged({source}) {
         if (source === this) { return; }
-        this.refresh();
+        void this.refresh();
     }
 
     /**
@@ -144,7 +144,7 @@ export class ScanInputsController {
         const scanningInput = ScanInputsController.createDefaultMouseInput('', '');
         this._addOption(index, scanningInput);
         this._updateCounts();
-        this._modifyProfileSettings([{
+        void this._modifyProfileSettings([{
             action: 'splice',
             path: 'scanning.inputs',
             start: index,
@@ -315,7 +315,7 @@ class ScanInputField {
      */
     _onIncludeValueChange({modifiers}) {
         const modifiers2 = this._joinModifiers(modifiers);
-        this._parent.setProperty(this._index, 'include', modifiers2, true);
+        void this._parent.setProperty(this._index, 'include', modifiers2, true);
     }
 
     /**
@@ -323,7 +323,7 @@ class ScanInputField {
      */
     _onExcludeValueChange({modifiers}) {
         const modifiers2 = this._joinModifiers(modifiers);
-        this._parent.setProperty(this._index, 'exclude', modifiers2, true);
+        void this._parent.setProperty(this._index, 'exclude', modifiers2, true);
     }
 
     /**
@@ -406,7 +406,7 @@ class ScanInputField {
         if (this._node !== null) {
             this._node.dataset.showAdvanced = `${showAdvanced}`;
         }
-        this._parent.setProperty(this._index, 'options.showAdvanced', showAdvanced, false);
+        void this._parent.setProperty(this._index, 'options.showAdvanced', showAdvanced, false);
     }
 
     /**
diff --git a/ext/js/pages/settings/scan-inputs-simple-controller.js b/ext/js/pages/settings/scan-inputs-simple-controller.js
index b09a3a76..53a52922 100644
--- a/ext/js/pages/settings/scan-inputs-simple-controller.js
+++ b/ext/js/pages/settings/scan-inputs-simple-controller.js
@@ -70,7 +70,7 @@ export class ScanInputsSimpleController {
      */
     _onScanInputsChanged({source}) {
         if (source === this) { return; }
-        this.refresh();
+        void this.refresh();
     }
 
     /**
@@ -112,7 +112,7 @@ export class ScanInputsSimpleController {
     onMiddleMouseButtonScanChange(e) {
         const element = /** @type {HTMLInputElement} */ (e.currentTarget);
         const middleMouseSupported = element.checked;
-        this._setMiddleMouseSuppported(middleMouseSupported);
+        void this._setMiddleMouseSuppported(middleMouseSupported);
     }
 
     /**
@@ -123,7 +123,7 @@ export class ScanInputsSimpleController {
         const mainScanKey = element.value;
         if (mainScanKey === 'other') { return; }
         const mainScanInputs = (mainScanKey === 'none' ? [] : [mainScanKey]);
-        this._setMainScanInputs(mainScanInputs);
+        void this._setMainScanInputs(mainScanInputs);
     }
 
     /**
diff --git a/ext/js/pages/settings/sentence-termination-characters-controller.js b/ext/js/pages/settings/sentence-termination-characters-controller.js
index 4ceed22b..7eee3d3e 100644
--- a/ext/js/pages/settings/sentence-termination-characters-controller.js
+++ b/ext/js/pages/settings/sentence-termination-characters-controller.js
@@ -135,7 +135,7 @@ export class SentenceTerminationCharactersController {
      */
     _onAddClick(e) {
         e.preventDefault();
-        this._addNewEntry();
+        void this._addNewEntry();
     }
 
     /**
@@ -143,7 +143,7 @@ export class SentenceTerminationCharactersController {
      */
     _onResetClick(e) {
         e.preventDefault();
-        this._reset();
+        void this._reset();
     }
 
     /** */
@@ -258,7 +258,7 @@ class SentenceTerminationCharacterEntry {
      */
     _onTypeSelectChange(e) {
         const element = /** @type {HTMLSelectElement} */ (e.currentTarget);
-        this._setHasCharacter2(element.value === 'quote');
+        void this._setHasCharacter2(element.value === 'quote');
     }
 
     /**
@@ -272,7 +272,7 @@ class SentenceTerminationCharacterEntry {
         }
 
         const value = node.value.substring(0, 1);
-        this._setCharacterValue(node, characterNumber, value);
+        void this._setCharacterValue(node, characterNumber, value);
     }
 
     /**
@@ -281,14 +281,14 @@ class SentenceTerminationCharacterEntry {
     _onMenuClose(e) {
         switch (e.detail.action) {
             case 'delete':
-                this._delete();
+                void this._delete();
                 break;
         }
     }
 
     /** */
     async _delete() {
-        this._parent.deleteEntry(this._index);
+        void this._parent.deleteEntry(this._index);
     }
 
     /**
diff --git a/ext/js/pages/settings/settings-controller.js b/ext/js/pages/settings/settings-controller.js
index d0cfd838..282479de 100644
--- a/ext/js/pages/settings/settings-controller.js
+++ b/ext/js/pages/settings/settings-controller.js
@@ -239,7 +239,7 @@ export class SettingsController extends EventDispatcher {
     _setProfileIndex(value, canUpdateProfileIndex) {
         this._profileIndex = value;
         this.trigger('optionsContextChanged', {});
-        this._onOptionsUpdatedInternal(canUpdateProfileIndex);
+        void this._onOptionsUpdatedInternal(canUpdateProfileIndex);
     }
 
     /**
@@ -247,7 +247,7 @@ export class SettingsController extends EventDispatcher {
      */
     _onOptionsUpdated({source}) {
         if (source === this._source) { return; }
-        this._onOptionsUpdatedInternal(true);
+        void this._onOptionsUpdatedInternal(true);
     }
 
     /**
@@ -332,7 +332,7 @@ export class SettingsController extends EventDispatcher {
 
     /** */
     _onPermissionsChanged() {
-        this._triggerPermissionsChanged();
+        void this._triggerPermissionsChanged();
     }
 
     /** */
diff --git a/ext/js/pages/settings/settings-main.js b/ext/js/pages/settings/settings-main.js
index 82fc91a5..df43df9b 100644
--- a/ext/js/pages/settings/settings-main.js
+++ b/ext/js/pages/settings/settings-main.js
@@ -91,13 +91,13 @@ await Application.main(true, async (application) => {
     await settingsController.prepare();
 
     const persistentStorageController = new PersistentStorageController(application);
-    persistentStorageController.prepare();
+    preparePromises.push(persistentStorageController.prepare());
 
     const storageController = new StorageController(persistentStorageController);
     storageController.prepare();
 
     const dictionaryController = new DictionaryController(settingsController, modalController, statusFooter);
-    dictionaryController.prepare();
+    preparePromises.push(dictionaryController.prepare());
 
     const dictionaryImportController = new DictionaryImportController(settingsController, modalController, statusFooter);
     dictionaryImportController.prepare();
@@ -106,52 +106,52 @@ await Application.main(true, async (application) => {
     preparePromises.push(setupGenericSettingController(genericSettingController));
 
     const audioController = new AudioController(settingsController, modalController);
-    audioController.prepare();
+    preparePromises.push(audioController.prepare());
 
     const profileController = new ProfileController(settingsController, modalController);
-    profileController.prepare();
+    preparePromises.push(profileController.prepare());
 
     const settingsBackup = new BackupController(settingsController, modalController);
-    settingsBackup.prepare();
+    preparePromises.push(settingsBackup.prepare());
 
     const ankiController = new AnkiController(settingsController);
-    ankiController.prepare();
+    preparePromises.push(ankiController.prepare());
 
     const ankiTemplatesController = new AnkiTemplatesController(settingsController, modalController, ankiController);
-    ankiTemplatesController.prepare();
+    preparePromises.push(ankiTemplatesController.prepare());
 
     const popupPreviewController = new PopupPreviewController(settingsController);
     popupPreviewController.prepare();
 
     const scanInputsController = new ScanInputsController(settingsController);
-    scanInputsController.prepare();
+    preparePromises.push(scanInputsController.prepare());
 
     const simpleScanningInputController = new ScanInputsSimpleController(settingsController);
-    simpleScanningInputController.prepare();
+    preparePromises.push(simpleScanningInputController.prepare());
 
     const nestedPopupsController = new NestedPopupsController(settingsController);
-    nestedPopupsController.prepare();
+    preparePromises.push(nestedPopupsController.prepare());
 
     const permissionsToggleController = new PermissionsToggleController(settingsController);
-    permissionsToggleController.prepare();
+    preparePromises.push(permissionsToggleController.prepare());
 
     const secondarySearchDictionaryController = new SecondarySearchDictionaryController(settingsController);
-    secondarySearchDictionaryController.prepare();
+    preparePromises.push(secondarySearchDictionaryController.prepare());
 
     const languagesController = new LanguagesController(settingsController);
-    languagesController.prepare();
+    preparePromises.push(languagesController.prepare());
 
     const translationTextReplacementsController = new TranslationTextReplacementsController(settingsController);
-    translationTextReplacementsController.prepare();
+    preparePromises.push(translationTextReplacementsController.prepare());
 
     const sentenceTerminationCharactersController = new SentenceTerminationCharactersController(settingsController);
-    sentenceTerminationCharactersController.prepare();
+    preparePromises.push(sentenceTerminationCharactersController.prepare());
 
     const keyboardShortcutController = new KeyboardShortcutController(settingsController);
-    keyboardShortcutController.prepare();
+    preparePromises.push(keyboardShortcutController.prepare());
 
     const extensionKeyboardShortcutController = new ExtensionKeyboardShortcutController(settingsController);
-    extensionKeyboardShortcutController.prepare();
+    preparePromises.push(extensionKeyboardShortcutController.prepare());
 
     const popupWindowController = new PopupWindowController(application.api);
     popupWindowController.prepare();
@@ -160,10 +160,10 @@ await Application.main(true, async (application) => {
     mecabController.prepare();
 
     const collapsibleDictionaryController = new CollapsibleDictionaryController(settingsController);
-    collapsibleDictionaryController.prepare();
+    preparePromises.push(collapsibleDictionaryController.prepare());
 
     const sortFrequencyDictionaryController = new SortFrequencyDictionaryController(settingsController);
-    sortFrequencyDictionaryController.prepare();
+    preparePromises.push(sortFrequencyDictionaryController.prepare());
 
     await Promise.all(preparePromises);
 
diff --git a/ext/js/pages/settings/sort-frequency-dictionary-controller.js b/ext/js/pages/settings/sort-frequency-dictionary-controller.js
index c8e9918b..a88a2d47 100644
--- a/ext/js/pages/settings/sort-frequency-dictionary-controller.js
+++ b/ext/js/pages/settings/sort-frequency-dictionary-controller.js
@@ -79,7 +79,7 @@ export class SortFrequencyDictionaryController {
     /** */
     _onSortFrequencyDictionarySelectChange() {
         const {value} = /** @type {HTMLSelectElement} */ (this._sortFrequencyDictionarySelect);
-        this._setSortFrequencyDictionaryValue(value !== '' ? value : null);
+        void this._setSortFrequencyDictionaryValue(value !== '' ? value : null);
     }
 
     /** */
@@ -87,14 +87,14 @@ export class SortFrequencyDictionaryController {
         const {value} = /** @type {HTMLSelectElement} */ (this._sortFrequencyDictionaryOrderSelect);
         const value2 = this._normalizeSortFrequencyDictionaryOrder(value);
         if (value2 === null) { return; }
-        this._setSortFrequencyDictionaryOrderValue(value2);
+        void this._setSortFrequencyDictionaryOrderValue(value2);
     }
 
     /** */
     _onSortFrequencyDictionaryOrderAutoButtonClick() {
         const {value} = /** @type {HTMLSelectElement} */ (this._sortFrequencyDictionarySelect);
         if (value === '') { return; }
-        this._autoUpdateOrder(value);
+        void this._autoUpdateOrder(value);
     }
 
     /**
diff --git a/ext/js/pages/settings/storage-controller.js b/ext/js/pages/settings/storage-controller.js
index 9a3aa23a..31331d90 100644
--- a/ext/js/pages/settings/storage-controller.js
+++ b/ext/js/pages/settings/storage-controller.js
@@ -62,19 +62,19 @@ export class StorageController {
         storageRefreshButton.addEventListener('click', this._onStorageRefreshButtonClick.bind(this), false);
         this._persistentStorageController.application.on('storageChanged', this._onStorageChanged.bind(this));
 
-        this._updateStats();
+        void this._updateStats();
     }
 
     // Private
 
     /** */
     _onStorageRefreshButtonClick() {
-        this._updateStats();
+        void this._updateStats();
     }
 
     /** */
     _onStorageChanged() {
-        this._updateStats();
+        void this._updateStats();
     }
 
     /** */
diff --git a/ext/js/pages/settings/translation-text-replacements-controller.js b/ext/js/pages/settings/translation-text-replacements-controller.js
index 98a16026..f2255ae0 100644
--- a/ext/js/pages/settings/translation-text-replacements-controller.js
+++ b/ext/js/pages/settings/translation-text-replacements-controller.js
@@ -133,7 +133,7 @@ export class TranslationTextReplacementsController {
 
     /** */
     _onAdd() {
-        this.addGroup();
+        void this.addGroup();
     }
 
     /** */
@@ -242,7 +242,7 @@ class TranslationTextReplacementsEntry {
     _onMenuClose(e) {
         switch (e.detail.action) {
             case 'remove':
-                this._parent.deleteGroup(this._index);
+                void this._parent.deleteGroup(this._index);
                 break;
             case 'showTest':
                 this._setTestVisible(true);
diff --git a/ext/js/pages/welcome-main.js b/ext/js/pages/welcome-main.js
index d1d1a6b2..23511dd6 100644
--- a/ext/js/pages/welcome-main.js
+++ b/ext/js/pages/welcome-main.js
@@ -49,6 +49,15 @@ async function setupGenericSettingsController(genericSettingController) {
     await genericSettingController.refresh();
 }
 
+/** */
+async function checkNeedsCustomTemplatesWarning() {
+    const key = 'needsCustomTemplatesWarning';
+    const result = await chrome.storage.session.get({[key]: false});
+    if (!result[key]) { return; }
+    document.documentElement.dataset.warnCustomTemplates = 'true';
+    await chrome.storage.session.remove([key]);
+}
+
 await Application.main(true, async (application) => {
     const documentFocusController = new DocumentFocusController();
     documentFocusController.prepare();
@@ -61,14 +70,8 @@ await Application.main(true, async (application) => {
     const statusFooter = new StatusFooter(statusFooterElement);
     statusFooter.prepare();
 
-    setupEnvironmentInfo(application.api);
-
-    chrome.storage.session.get({needsCustomTemplatesWarning: false}).then((result) => {
-        if (result.needsCustomTemplatesWarning) {
-            document.documentElement.dataset.warnCustomTemplates = 'true';
-            chrome.storage.session.remove(['needsCustomTemplatesWarning']);
-        }
-    });
+    void setupEnvironmentInfo(application.api);
+    void checkNeedsCustomTemplatesWarning();
 
     const preparePromises = [];
 
@@ -79,19 +82,19 @@ await Application.main(true, async (application) => {
     await settingsController.prepare();
 
     const dictionaryController = new DictionaryController(settingsController, modalController, statusFooter);
-    dictionaryController.prepare();
+    preparePromises.push(dictionaryController.prepare());
 
     const dictionaryImportController = new DictionaryImportController(settingsController, modalController, statusFooter);
-    dictionaryImportController.prepare();
+    preparePromises.push(dictionaryImportController.prepare());
 
     const genericSettingController = new GenericSettingController(settingsController);
     preparePromises.push(setupGenericSettingsController(genericSettingController));
 
     const simpleScanningInputController = new ScanInputsSimpleController(settingsController);
-    simpleScanningInputController.prepare();
+    preparePromises.push(simpleScanningInputController.prepare());
 
     const recommendedPermissionsController = new RecommendedPermissionsController(settingsController);
-    recommendedPermissionsController.prepare();
+    preparePromises.push(recommendedPermissionsController.prepare());
 
     await Promise.all(preparePromises);
 
diff --git a/test/data/html/js/html-test-utilities.js b/test/data/html/js/html-test-utilities.js
index c3382456..34e58807 100644
--- a/test/data/html/js/html-test-utilities.js
+++ b/test/data/html/js/html-test-utilities.js
@@ -26,38 +26,38 @@ class HtmlTestUtilities {
      */
     static requestFullscreen(element) {
         if (element.requestFullscreen) {
-            element.requestFullscreen();
+            void element.requestFullscreen();
             // @ts-expect-error - Browser compatibility
         } else if (element.mozRequestFullScreen) {
             // @ts-expect-error - Browser compatibility
-            element.mozRequestFullScreen();
+            void element.mozRequestFullScreen();
             // @ts-expect-error - Browser compatibility
         } else if (element.webkitRequestFullscreen) {
             // @ts-expect-error - Browser compatibility
-            element.webkitRequestFullscreen();
+            void element.webkitRequestFullscreen();
             // @ts-expect-error - Browser compatibility
         } else if (element.msRequestFullscreen) {
             // @ts-expect-error - Browser compatibility
-            element.msRequestFullscreen();
+            void element.msRequestFullscreen();
         }
     }
 
     /** */
     static exitFullscreen() {
         if (document.exitFullscreen) {
-            document.exitFullscreen();
+            void document.exitFullscreen();
             // @ts-expect-error - Browser compatibility
         } else if (document.mozCancelFullScreen) {
             // @ts-expect-error - Browser compatibility
-            document.mozCancelFullScreen();
+            void document.mozCancelFullScreen();
             // @ts-expect-error - Browser compatibility
         } else if (document.webkitExitFullscreen) {
             // @ts-expect-error - Browser compatibility
-            document.webkitExitFullscreen();
+            void document.webkitExitFullscreen();
             // @ts-expect-error - Browser compatibility
         } else if (document.msExitFullscreen) {
             // @ts-expect-error - Browser compatibility
-            document.msExitFullscreen();
+            void document.msExitFullscreen();
         }
     }
 
diff --git a/test/fixtures/dom-test.js b/test/fixtures/dom-test.js
index 961e0a77..459383cc 100644
--- a/test/fixtures/dom-test.js
+++ b/test/fixtures/dom-test.js
@@ -69,7 +69,7 @@ export function createDomTest(htmlFilePath) {
             try {
                 await use(window);
             } finally {
-                environment.teardown(global);
+                await environment.teardown(global);
             }
         }
     });
diff --git a/test/playwright/integration.spec.js b/test/playwright/integration.spec.js
index 06af3fd2..4957b676 100644
--- a/test/playwright/integration.spec.js
+++ b/test/playwright/integration.spec.js
@@ -51,7 +51,7 @@ test('anki add', async ({context, page, extensionId}) => {
         resolve = res;
     });
     await context.route(/127.0.0.1:8765\/*/, (route) => {
-        mockAnkiRouteHandler(route);
+        void mockAnkiRouteHandler(route);
         const req = route.request();
         if (req.url().includes('127.0.0.1:8765') && req.postDataJSON().action === 'addNote') {
             /** @type {(value: unknown) => void} */ (resolve)(req.postDataJSON());
diff --git a/test/playwright/playwright-util.js b/test/playwright/playwright-util.js
index b9a4831a..653112c6 100644
--- a/test/playwright/playwright-util.js
+++ b/test/playwright/playwright-util.js
@@ -68,16 +68,16 @@ export const mockModelFieldsToAnkiValues = {
 
 /**
  * @param {import('playwright').Route} route
- * @returns {Promise<void>|undefined}
+ * @returns {Promise<void>}
  */
-export const mockAnkiRouteHandler = (route) => {
+export async function mockAnkiRouteHandler(route) {
     const reqBody = route.request().postDataJSON();
     const respBody = ankiRouteResponses[reqBody.action];
     if (!respBody) {
         return route.abort();
     }
-    route.fulfill(respBody);
-};
+    await route.fulfill(respBody);
+}
 
 /**
  * @param {import('playwright').Page} page
diff --git a/test/playwright/visual.spec.js b/test/playwright/visual.spec.js
index 157cedc7..579c2d0b 100644
--- a/test/playwright/visual.spec.js
+++ b/test/playwright/visual.spec.js
@@ -22,7 +22,7 @@ import {expect, root, test} from './playwright-util.js';
 test.beforeEach(async ({context}) => {
     // Wait for the on-install welcome.html tab to load, which becomes the foreground tab
     const welcome = await context.waitForEvent('page');
-    welcome.close(); // Close the welcome tab so our main tab becomes the foreground tab -- otherwise, the screenshot can hang
+    await welcome.close(); // Close the welcome tab so our main tab becomes the foreground tab -- otherwise, the screenshot can hang
 });
 
 test('visual', async ({page, extensionId}) => {
diff --git a/types/ext/settings-modifications.d.ts b/types/ext/settings-modifications.d.ts
index becfea5c..e70ff7e8 100644
--- a/types/ext/settings-modifications.d.ts
+++ b/types/ext/settings-modifications.d.ts
@@ -97,7 +97,10 @@ export type ModificationSpliceResult = unknown[];
 
 export type ModificationPushResult = number;
 
+// There is some redundancy with this type currently due to the `unknown`s used in it.
+// For now, this is fine, but the types could be improved in the future.
 export type ModificationResult = (
+    // eslint-disable-next-line @typescript-eslint/no-redundant-type-constituents
     ModificationSetResult |
     ModificationDeleteResult |
     // eslint-disable-next-line @typescript-eslint/no-duplicate-type-constituents