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, 6 insertions, 10 deletions

diff --git a/ext/js/background/backend.js b/ext/js/background/backend.js
index 090ba7b3..8ab56232 100644
--- a/ext/js/background/backend.js
+++ b/ext/js/background/backend.js
@@ -701,7 +701,7 @@ export class Backend {
                 typeof chrome.tabs.getZoom === 'function'
             )) {
                 // Not supported
-                resolve({zoomFactor: 1.0});
+                resolve({zoomFactor: 1});
                 return;
             }
             chrome.tabs.getZoom(tabId, (zoomFactor) => {
@@ -1701,10 +1701,8 @@ export class Backend {
                 // NOP
             }
 
-            if (okay && !done) {
-                if (add(item)) {
-                    done = true;
-                }
+            if (okay && !done && add(item)) {
+                done = true;
             }
         };
 
@@ -2294,7 +2292,7 @@ export class Backend {
      */
     _replaceInvalidFileNameCharacters(fileName) {
         // eslint-disable-next-line no-control-regex
-        return fileName.replace(/[<>:"/\\|?*\x00-\x1F]/g, '-');
+        return fileName.replace(/[<>:"/\\|?*\u0000-\u001F]/g, '-');
     }
 
     /**
diff --git a/ext/js/background/offscreen-proxy.js b/ext/js/background/offscreen-proxy.js
index 8c3f63c9..2351cb96 100644
--- a/ext/js/background/offscreen-proxy.js
+++ b/ext/js/background/offscreen-proxy.js
@@ -144,8 +144,7 @@ export class DictionaryDatabaseProxy {
      */
     async getMedia(targets) {
         const serializedMedia = /** @type {import('dictionary-database').Media<string>[]} */ (await this._offscreen.sendMessagePromise({action: 'databaseGetMediaOffscreen', params: {targets}}));
-        const media = serializedMedia.map((m) => ({...m, content: base64ToArrayBuffer(m.content)}));
-        return media;
+        return serializedMedia.map((m) => ({...m, content: base64ToArrayBuffer(m.content)}));
     }
 }
 
diff --git a/ext/js/background/offscreen.js b/ext/js/background/offscreen.js
index 754db517..dbdb9773 100644
--- a/ext/js/background/offscreen.js
+++ b/ext/js/background/offscreen.js
@@ -109,8 +109,7 @@ export class Offscreen {
     /** @type {import('offscreen').ApiHandler<'databaseGetMediaOffscreen'>} */
     async _getMediaHandler({targets}) {
         const media = await this._dictionaryDatabase.getMedia(targets);
-        const serializedMedia = media.map((m) => ({...m, content: arrayBufferToBase64(m.content)}));
-        return serializedMedia;
+        return media.map((m) => ({...m, content: arrayBufferToBase64(m.content)}));
     }
 
     /** @type {import('offscreen').ApiHandler<'translatorPrepareOffscreen'>} */