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

3 files changed, 10 insertions, 12 deletions

diff --git a/ext/js/language/ja/japanese.js b/ext/js/language/ja/japanese.js
index a4508040..818daa0b 100644
--- a/ext/js/language/ja/japanese.js
+++ b/ext/js/language/ja/japanese.js
@@ -92,7 +92,7 @@ const JAPANESE_RANGES = [
     [0xffe0, 0xffee] // Currency markers
 ];
 
-const SMALL_KANA_SET = new Set(Array.from('ぁぃぅぇぉゃゅょゎァィゥェォャュョヮ'));
+const SMALL_KANA_SET = new Set('ぁぃぅぇぉゃゅょゎァィゥェォャュョヮ');
 
 const HALFWIDTH_KATAKANA_MAPPING = new Map([
     ['ｦ', 'ヲヺ-'],
diff --git a/ext/js/language/text-scanner.js b/ext/js/language/text-scanner.js
index 811c7987..1cf346a9 100644
--- a/ext/js/language/text-scanner.js
+++ b/ext/js/language/text-scanner.js
@@ -1294,11 +1294,9 @@ export class TextScanner extends EventDispatcher {
     async _searchAtFromMouseMove(x, y, inputInfo) {
         if (this._pendingLookup) { return; }
 
-        if (inputInfo.passive) {
-            if (!await this._scanTimerWait()) {
-                // Aborted
-                return;
-            }
+        if (inputInfo.passive && !await this._scanTimerWait()) {
+            // Aborted
+            return;
         }
 
         await this._searchAt(x, y, inputInfo);
diff --git a/ext/js/language/translator.js b/ext/js/language/translator.js
index 007a7d1e..2ba1ce0d 100644
--- a/ext/js/language/translator.js
+++ b/ext/js/language/translator.js
@@ -491,11 +491,11 @@ export class Translator {
      * @returns {number}
      */
     _getNextSubstringLength(searchResolution, currentLength, source) {
-        if (searchResolution === 'word') {
-            return source.search(/[^\p{Letter}][\p{Letter}\p{Number}]*$/u);
-        } else {
-            return currentLength - 1;
-        }
+        return (
+            searchResolution === 'word' ?
+            source.search(/[^\p{Letter}][\p{Letter}\p{Number}]*$/u) :
+            currentLength - 1
+        );
     }
 
     /**
@@ -620,7 +620,7 @@ export class Translator {
             for (const group of groupedDictionaryEntries) {
                 this._sortTermDictionaryEntriesById(group.dictionaryEntries);
             }
-            if (ungroupedDictionaryEntriesMap.size !== 0 || secondarySearchDictionaryMap.size !== 0) {
+            if (ungroupedDictionaryEntriesMap.size > 0 || secondarySearchDictionaryMap.size > 0) {
                 await this._addSecondaryRelatedDictionaryEntries(groupedDictionaryEntries, ungroupedDictionaryEntriesMap, enabledDictionaryMap, secondarySearchDictionaryMap, tagAggregator);
             }
         }