more strict lint

src/content/follow.js

@@ -1,7 +1,7 @@
 import Hint from './hint';
 import HintKeyProducer from './hint-key-producer';
 
-const DEFAULT_HINT_CHARSET = 'abcdefghijklmnopqrstuvwxyz'
+const DEFAULT_HINT_CHARSET = 'abcdefghijklmnopqrstuvwxyz';
 
 export default class Follow {
   constructor(doc) {
@@ -22,14 +22,14 @@ export default class Follow {
     let producer = new HintKeyProducer(DEFAULT_HINT_CHARSET);
     Array.prototype.forEach.call(elements, (ele) => {
       let keys = producer.produce();
-      let hint = new Hint(ele, keys)
+      let hint = new Hint(ele, keys);
 
       this.hintElements[keys] = hint;
     });
   }
 
   handleKeydown(e) {
-    let keyCode = e.keyCode;
+    let { keyCode } = e;
     if (keyCode === KeyboardEvent.DOM_VK_ESCAPE) {
       this.remove();
       return;
@@ -56,10 +56,10 @@ export default class Follow {
     let hidden = Object.keys(this.hintElements).filter((key) => {
       return !key.startsWith(chars);
     });
-    if (shown.length == 0) {
+    if (shown.length === 0) {
       this.remove();
       return;
-    } else if (shown.length == 1) {
+    } else if (shown.length === 1) {
       this.remove();
       this.hintElements[chars].activate();
     }
@@ -74,7 +74,7 @@ export default class Follow {
 
 
   remove() {
-    this.doc.removeEventListener("keydown", this.boundKeydown);
+    this.doc.removeEventListener('keydown', this.boundKeydown);
     Object.keys(this.hintElements).forEach((key) => {
       this.hintElements[key].remove();
     });
@@ -87,6 +87,14 @@ export default class Follow {
     );
   }
 
+  static isNumericKey(code) {
+    return KeyboardEvent.DOM_VK_0 <= code && code <= KeyboardEvent.DOM_VK_9;
+  }
+
+  static isAlphabeticKey(code) {
+    return KeyboardEvent.DOM_VK_A <= code && code <= KeyboardEvent.DOM_VK_Z;
+  }
+
   static codeChars(codes) {
     const CHARCODE_ZERO = '0'.charCodeAt(0);
     const CHARCODE_A = 'a'.charCodeAt(0);
@@ -94,10 +102,12 @@ export default class Follow {
     let chars = '';
 
     for (let code of codes) {
-      if (KeyboardEvent.DOM_VK_0 <= code && code <= KeyboardEvent.DOM_VK_9) {
-        chars += String.fromCharCode(code - KeyboardEvent.DOM_VK_0 + CHARCODE_ZERO);
-      } else if (KeyboardEvent.DOM_VK_A <= code && code <= KeyboardEvent.DOM_VK_Z) {
-        chars += String.fromCharCode(code - KeyboardEvent.DOM_VK_A + CHARCODE_A);
+      if (Follow.isNumericKey(code)) {
+        chars += String.fromCharCode(
+          code - KeyboardEvent.DOM_VK_0 + CHARCODE_ZERO);
+      } else if (Follow.isAlphabeticKey(code)) {
+        chars += String.fromCharCode(
+          code - KeyboardEvent.DOM_VK_A + CHARCODE_A);
       }
     }
     return chars;
@@ -112,7 +122,7 @@ export default class Follow {
   }
 
   static isVisibleElement(element) {
-    var style = window.getComputedStyle(element);
+    let style = window.getComputedStyle(element);
     if (style.display === 'none') {
       return false;
     } else if (style.visibility === 'hidden') {

src/content/hint-key-producer.js

@@ -11,19 +11,19 @@ export default class HintKeyProducer {
   produce() {
     this.increment();
 
-    return this.counter.map((x) => this.charset[x]).join('');
+    return this.counter.map(x => this.charset[x]).join('');
   }
 
   increment() {
     let max = this.charset.length - 1;
-    if (this.counter.every((x) => x == max)) {
+    if (this.counter.every(x => x === max)) {
       this.counter = new Array(this.counter.length + 1).fill(0);
       return;
     }
 
     this.counter.reverse();
     let len = this.charset.length;
-    let num = this.counter.reduce((x,y,index) => x + y * (len ** index)) + 1;
+    let num = this.counter.reduce((x, y, index) => x + y * len ** index) + 1;
     for (let i = 0; i < this.counter.length; ++i) {
       this.counter[i] = num % len;
       num = ~~(num / len);

src/content/hint.js

@@ -8,10 +8,9 @@ export default class Hint {
 
     this.target = target;
 
-    let doc = target.ownerDocument
+    let doc = target.ownerDocument;
     let { top, left } = target.getBoundingClientRect();
-    let scrollX = window.scrollX;
-    let scrollY = window.scrollY;
+    let { scrollX, scrollY } = window;
 
     this.element = doc.createElement('span');
     this.element.className = 'vimvixen-hint';

src/content/histories.js

@@ -1,8 +1,8 @@
 const prev = (win) => {
-  win.history.back()
+  win.history.back();
 };
 const next = (win) => {
-  win.history.forward()
+  win.history.forward();
 };
 
 export { prev, next };

src/content/index.js

@@ -4,11 +4,11 @@ import * as scrolls from '../content/scrolls';
 import * as histories from '../content/histories';
 import Follow from '../content/follow';
 import operations from '../operations';
-import messages  from '../messages';
+import messages from '../messages';
 
 consoleFrames.initialize(window.document);
 
-window.addEventListener("keypress", (e) => {
+window.addEventListener('keypress', (e) => {
   if (e.target instanceof HTMLInputElement) {
     return;
   }
@@ -40,14 +40,14 @@ const execOperation = (operation) => {
   case operations.HISTORY_NEXT:
     return histories.next(window);
   }
-}
+};
 
 const update = (state) => {
   if (!state.console.commandShown) {
     window.focus();
     consoleFrames.blur(window.document);
   }
-}
+};
 
 browser.runtime.onMessage.addListener((action) => {
   switch (action.type) {

src/content/scrolls.js

@@ -37,4 +37,6 @@ const scrollRight = (page) => {
   page.scrollTo(x, y);
 };
 
-export { scrollLines, scrollPages, scrollTop, scrollBottom, scrollLeft, scrollRight }
+export {
+  scrollLines, scrollPages, scrollTop, scrollBottom, scrollLeft, scrollRight
+};