Eslint rule updates (#673)

* Install unicorn

* Add rules

* Fix issues

* Install sonarjs

* Set up rules

* Fix issues

* Install eslint-plugin-import and fix import extensions

* Simplify permitted error names

12 files changed, 24 insertions, 26 deletions

diff --git a/ext/js/pages/settings/anki-controller.js b/ext/js/pages/settings/anki-controller.js
index 3a6345ed..e161d86b 100644
--- a/ext/js/pages/settings/anki-controller.js
+++ b/ext/js/pages/settings/anki-controller.js
@@ -401,11 +401,11 @@ export class AnkiController {
         if (typeof data !== 'undefined') {
             details += `${JSON.stringify(data, null, 4)}\n\n`;
         }
-        details += `${error.stack}`.trimRight();
+        details += `${error.stack}`.trimEnd();
         /** @type {HTMLElement} */ (this._ankiErrorMessageDetailsNode).textContent = details;
 
         /** @type {HTMLElement} */ (this._ankiErrorMessageDetailsContainer).hidden = true;
-        /** @type {HTMLElement} */ (this._ankiErrorInvalidResponseInfo).hidden = (errorString.indexOf('Invalid response') < 0);
+        /** @type {HTMLElement} */ (this._ankiErrorInvalidResponseInfo).hidden = !errorString.includes('Invalid response');
         /** @type {HTMLElement} */ (this._ankiErrorMessageDetailsToggle).hidden = false;
     }
 
@@ -762,7 +762,8 @@ class AnkiCardController {
         const ELEMENT_NODE = Node.ELEMENT_NODE;
         const container = this._ankiCardFieldsContainer;
         if (container !== null) {
-            for (const node of [...container.childNodes]) {
+            const childNodesFrozen = [...container.childNodes];
+            for (const node of childNodesFrozen) {
                 if (node.nodeType === ELEMENT_NODE && node instanceof HTMLElement && node.dataset.persistent === 'true') { continue; }
                 container.removeChild(node);
             }
diff --git a/ext/js/pages/settings/audio-controller.js b/ext/js/pages/settings/audio-controller.js
index 9633c4b3..5b597d33 100644
--- a/ext/js/pages/settings/audio-controller.js
+++ b/ext/js/pages/settings/audio-controller.js
@@ -144,7 +144,7 @@ export class AudioController extends EventDispatcher {
             const text = input.value || '';
             const voiceUri = input.dataset.voice;
             const audio = this._audioSystem.createTextToSpeechAudio(text, typeof voiceUri === 'string' ? voiceUri : '');
-            audio.volume = 1.0;
+            audio.volume = 1;
             audio.play();
         } catch (e) {
             // NOP
diff --git a/ext/js/pages/settings/backup-controller.js b/ext/js/pages/settings/backup-controller.js
index 59bcaed9..2bab00e3 100644
--- a/ext/js/pages/settings/backup-controller.js
+++ b/ext/js/pages/settings/backup-controller.js
@@ -144,7 +144,7 @@ export class BackupController {
             }
         }
 
-        const data = {
+        return {
             version: this._currentVersion,
             date: this._getSettingsExportDateString(date, '-', ' ', ':', 6),
             url: chrome.runtime.getURL('/'),
@@ -154,8 +154,6 @@ export class BackupController {
             permissions,
             options: optionsFull
         };
-
-        return data;
     }
 
     /**
diff --git a/ext/js/pages/settings/collapsible-dictionary-controller.js b/ext/js/pages/settings/collapsible-dictionary-controller.js
index 5ba61e0c..62f84b96 100644
--- a/ext/js/pages/settings/collapsible-dictionary-controller.js
+++ b/ext/js/pages/settings/collapsible-dictionary-controller.js
@@ -156,9 +156,7 @@ export class CollapsibleDictionaryController {
         const versionNode = querySelectorNotNull(node, '.dictionary-version');
         versionNode.textContent = version;
 
-        /** @type {HTMLSelectElement} */
-        const select = querySelectorNotNull(node, '.definitions-collapsible');
-        return select;
+        return querySelectorNotNull(node, '.definitions-collapsible');
     }
 
     /** */
diff --git a/ext/js/pages/settings/dictionary-controller.js b/ext/js/pages/settings/dictionary-controller.js
index 1d3c1730..5020dc7c 100644
--- a/ext/js/pages/settings/dictionary-controller.js
+++ b/ext/js/pages/settings/dictionary-controller.js
@@ -558,7 +558,7 @@ export class DictionaryController {
         const {profiles} = optionsFull;
         for (let i = 0, ii = profiles.length; i < ii; ++i) {
             let modified = false;
-            const missingDictionaries = new Set([...installedDictionaries]);
+            const missingDictionaries = new Set(installedDictionaries);
             const dictionaryOptionsArray = profiles[i].options.dictionaries;
             for (let j = dictionaryOptionsArray.length - 1; j >= 0; --j) {
                 const {name} = dictionaryOptionsArray[j];
@@ -871,8 +871,8 @@ export class DictionaryController {
             const onProgress = ({processed, count, storeCount, storesProcesed}) => {
                 const percent = (
                     (count > 0 && storesProcesed > 0) ?
-                    (processed / count) * (storesProcesed / storeCount) * 100.0 :
-                    0.0
+                    (processed / count) * (storesProcesed / storeCount) * 100 :
+                    0
                 );
                 const cssString = `${percent}%`;
                 const statusString = `${percent.toFixed(0)}%`;
diff --git a/ext/js/pages/settings/dictionary-import-controller.js b/ext/js/pages/settings/dictionary-import-controller.js
index 0484001d..34e21c5d 100644
--- a/ext/js/pages/settings/dictionary-import-controller.js
+++ b/ext/js/pages/settings/dictionary-import-controller.js
@@ -172,7 +172,7 @@ export class DictionaryImportController {
                     for (const label of infoLabels) { label.textContent = labelText; }
                 }
 
-                const percent = count > 0 ? (index / count * 100.0) : 0.0;
+                const percent = count > 0 ? (index / count * 100) : 0;
                 const cssString = `${percent}%`;
                 const statusString = `${Math.floor(percent).toFixed(0)}%`;
                 for (const progressBar of progressBars) { progressBar.style.width = cssString; }
@@ -199,8 +199,8 @@ export class DictionaryImportController {
 
                 await this._importDictionary(files[i], importDetails, onProgress);
             }
-        } catch (err) {
-            this._showErrors([toError(err)]);
+        } catch (error) {
+            this._showErrors([toError(error)]);
         } finally {
             prevention.end();
             for (const progress of progressContainers) { progress.hidden = true; }
diff --git a/ext/js/pages/settings/extension-keyboard-shortcuts-controller.js b/ext/js/pages/settings/extension-keyboard-shortcuts-controller.js
index 61eefffa..b9d107ae 100644
--- a/ext/js/pages/settings/extension-keyboard-shortcuts-controller.js
+++ b/ext/js/pages/settings/extension-keyboard-shortcuts-controller.js
@@ -353,7 +353,7 @@ class ExtensionKeyboardShortcutHotkeyEntry {
      * @param {boolean} updateInput
      */
     async _tryUpdateInput(key, modifiers, updateInput) {
-        let okay = (key === null ? (modifiers.length === 0) : (modifiers.length !== 0));
+        let okay = (key === null ? (modifiers.length === 0) : (modifiers.length > 0));
         if (okay) {
             try {
                 await this._parent.updateCommand(this._name, key, modifiers);
diff --git a/ext/js/pages/settings/keyboard-shortcuts-controller.js b/ext/js/pages/settings/keyboard-shortcuts-controller.js
index 7b28a322..907cf4a1 100644
--- a/ext/js/pages/settings/keyboard-shortcuts-controller.js
+++ b/ext/js/pages/settings/keyboard-shortcuts-controller.js
@@ -183,7 +183,7 @@ export class KeyboardShortcutController {
         const listContainer = /** @type {HTMLElement} */ (this._listContainer);
         listContainer.appendChild(fragment);
         listContainer.hidden = (hotkeys.length === 0);
-        /** @type {HTMLElement} */ (this._emptyIndicator).hidden = (hotkeys.length !== 0);
+        /** @type {HTMLElement} */ (this._emptyIndicator).hidden = (hotkeys.length > 0);
     }
 
     /**
diff --git a/ext/js/pages/settings/profile-controller.js b/ext/js/pages/settings/profile-controller.js
index 5a7b5ed4..a82a4b4e 100644
--- a/ext/js/pages/settings/profile-controller.js
+++ b/ext/js/pages/settings/profile-controller.js
@@ -544,7 +544,7 @@ export class ProfileController {
      */
     _tryGetValidProfileIndex(stringValue) {
         if (typeof stringValue !== 'string') { return null; }
-        const intValue = parseInt(stringValue, 10);
+        const intValue = Number.parseInt(stringValue, 10);
         return (
             Number.isFinite(intValue) &&
             intValue >= 0 &&
@@ -573,7 +573,7 @@ export class ProfileController {
             suffix = match[5];
             if (typeof match[2] === 'string') {
                 space = match[3];
-                index = parseInt(match[4], 10) + 1;
+                index = Number.parseInt(match[4], 10) + 1;
             } else {
                 space = ' ';
                 index = 2;
diff --git a/ext/js/pages/settings/sentence-termination-characters-controller.js b/ext/js/pages/settings/sentence-termination-characters-controller.js
index c393aaa1..4ceed22b 100644
--- a/ext/js/pages/settings/sentence-termination-characters-controller.js
+++ b/ext/js/pages/settings/sentence-termination-characters-controller.js
@@ -125,8 +125,9 @@ export class SentenceTerminationCharactersController {
             entry.prepare();
         }
 
-        /** @type {HTMLElement} */ (this._listTable).hidden = (terminationCharacters.length === 0);
-        /** @type {HTMLElement} */ (this._emptyIndicator).hidden = (terminationCharacters.length !== 0);
+        const empty = terminationCharacters.length === 0;
+        /** @type {HTMLElement} */ (this._listTable).hidden = empty;
+        /** @type {HTMLElement} */ (this._emptyIndicator).hidden = !empty;
     }
 
     /**
diff --git a/ext/js/pages/settings/settings-controller.js b/ext/js/pages/settings/settings-controller.js
index 3f389271..c835f8e6 100644
--- a/ext/js/pages/settings/settings-controller.js
+++ b/ext/js/pages/settings/settings-controller.js
@@ -195,6 +195,7 @@ export class SettingsController extends EventDispatcher {
      */
     preventPageExit() {
         /** @type {import('settings-controller').PageExitPrevention} */
+        // eslint-disable-next-line sonarjs/prefer-object-literal
         const obj = {};
         obj.end = this._endPreventPageExit.bind(this, obj);
         if (this._pageExitPreventionEventListeners.size === 0) {
@@ -226,8 +227,7 @@ export class SettingsController extends EventDispatcher {
     async getDefaultOptions() {
         const optionsUtil = new OptionsUtil();
         await optionsUtil.prepare();
-        const optionsFull = optionsUtil.getDefault();
-        return optionsFull;
+        return optionsUtil.getDefault();
     }
 
     // Private
diff --git a/ext/js/pages/settings/settings-display-controller.js b/ext/js/pages/settings/settings-display-controller.js
index 0a729d96..47aa9c9c 100644
--- a/ext/js/pages/settings/settings-display-controller.js
+++ b/ext/js/pages/settings/settings-display-controller.js
@@ -290,7 +290,7 @@ export class SettingsDisplayController {
      */
     _getMoreContainer(link) {
         const v = link.dataset.parentDistance;
-        const distance = v ? parseInt(v, 10) : 1;
+        const distance = v ? Number.parseInt(v, 10) : 1;
         if (Number.isNaN(distance)) { return null; }
 
         /** @type {?Element} */
@@ -338,7 +338,7 @@ export class SettingsDisplayController {
 
         let indent = '\t';
         if (args.length > 1) {
-            const count = parseInt(args[1], 10);
+            const count = Number.parseInt(args[1], 10);
             indent = (Number.isFinite(count) && count >= 0 ? ' '.repeat(count) : args[1]);
         }