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, 8 deletions

diff --git a/ext/js/app/frontend.js b/ext/js/app/frontend.js
index 27e7700e..84a8f1e6 100644
--- a/ext/js/app/frontend.js
+++ b/ext/js/app/frontend.js
@@ -82,9 +82,9 @@ export class Frontend {
         /** @type {?import('settings').ProfileOptions} */
         this._options = null;
         /** @type {number} */
-        this._pageZoomFactor = 1.0;
+        this._pageZoomFactor = 1;
         /** @type {number} */
-        this._contentScale = 1.0;
+        this._contentScale = 1;
         /** @type {Promise<void>} */
         this._lastShowPromise = Promise.resolve();
         /** @type {TextSourceGenerator} */
@@ -788,7 +788,7 @@ export class Frontend {
         }
         if (popupScaleRelativeToVisualViewport) {
             const {visualViewport} = window;
-            const visualViewportScale = (typeof visualViewport !== 'undefined' && visualViewport !== null ? visualViewport.scale : 1.0);
+            const visualViewportScale = (typeof visualViewport !== 'undefined' && visualViewport !== null ? visualViewport.scale : 1);
             contentScale /= visualViewportScale;
         }
         if (contentScale === this._contentScale) { return; }
diff --git a/ext/js/app/popup.js b/ext/js/app/popup.js
index 08ff0661..103a5468 100644
--- a/ext/js/app/popup.js
+++ b/ext/js/app/popup.js
@@ -68,7 +68,7 @@ export class Popup extends EventDispatcher {
         /** @type {?import('settings').OptionsContext} */
         this._optionsContext = null;
         /** @type {number} */
-        this._contentScale = 1.0;
+        this._contentScale = 1;
         /** @type {string} */
         this._targetOrigin = chrome.runtime.getURL('/').replace(/\/$/, '');
 
@@ -777,7 +777,7 @@ export class Popup extends EventDispatcher {
     _getPosition(sourceRects, writingMode, viewport) {
         sourceRects = this._convertSourceRectsCoordinateSpace(sourceRects);
         const contentScale = this._contentScale;
-        const scaleRatio = this._frameSizeContentScale === null ? 1.0 : contentScale / this._frameSizeContentScale;
+        const scaleRatio = this._frameSizeContentScale === null ? 1 : contentScale / this._frameSizeContentScale;
         this._frameSizeContentScale = contentScale;
         const frameRect = this._frame.getBoundingClientRect();
         const frameWidth = Math.max(frameRect.width * scaleRatio, this._initialWidth * contentScale);
@@ -1133,6 +1133,8 @@ class PopupError extends ExtensionError {
      */
     constructor(message, source) {
         super(message);
+        /** @type {string} */
+        this.name = 'PopupError';
         /** @type {Popup} */
         this._source = source;
     }
diff --git a/ext/js/app/theme-controller.js b/ext/js/app/theme-controller.js
index 559a6e57..384fbcc8 100644
--- a/ext/js/app/theme-controller.js
+++ b/ext/js/app/theme-controller.js
@@ -190,9 +190,9 @@ export class ThemeController {
         if (color === null) { return; }
 
         const a = color[3];
-        if (a <= 0.0) { return; }
+        if (a <= 0) { return; }
 
-        const aInv = 1.0 - a;
+        const aInv = 1 - a;
         for (let i = 0; i < 3; ++i) {
             target[i] = target[i] * aInv + color[i] * a;
         }
@@ -212,7 +212,7 @@ export class ThemeController {
             Number.parseInt(m[1], 10),
             Number.parseInt(m[2], 10),
             Number.parseInt(m[3], 10),
-            m4 ? Math.max(0.0, Math.min(1.0, Number.parseFloat(m4))) : 1.0
+            m4 ? Math.max(0, Math.min(1, Number.parseFloat(m4))) : 1
         ];
     }
 }