diff --git a/.eslintrc b/.eslintrc
index fa283fd..d3b3e9a 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -11,28 +11,47 @@
       "jsx": true
     }
   },
-  "extends": [ "eslint:recommended" ],
+  "extends": [ "eslint:all" ],
   "rules": {
+    "array-bracket-newline": ["error", { "multiline": true }],
     "arrow-body-style": "off",
+    "array-element-newline": "off",
+    "arrow-parens": ["error", "as-needed", { "requireForBlockBody": true }],
     "brace-style": ["error", "1tbs", { "allowSingleLine": true }],
+    "comma-dangle": "off",
+    "consistent-return": "off",
+    "default-case": "off",
     "id-length": "off",
     "indent": ["error", 2],
+    "max-statements": ["error", 15],
+    "multiline-ternary": "off",
     "newline-after-var": "off",
     "newline-before-return": "off",
-    "multiline-ternary": "off",
-    "max-statements": ["error", 15],
-    "no-console": "off",
-    "no-param-reassign": "off",
+    "no-magic-numbers": "off",
+    "no-bitwise": "off",
+    "no-use-before-define": "off",
+    "no-warning-comments": "off",
+    "no-console": ["error", { "allow": ["warn", "error"] }],
+    "no-empty-function": "off",
+    "no-mixed-operators": "off",
+    "no-plusplus": "off",
+    "capitalized-comments": "off",
     "no-ternary": "off",
+    "no-undefined": "off",
     "object-curly-spacing": [
       "error",
       "always", { "arraysInObjects": false, "objectsInObjects": false }
     ],
-    "object-curly-newline": "off",
-    "object-property-newline": "off",
+    "object-curly-newline": ["error", { "consistent": true }],
+    "object-property-newline": ["error", { "allowMultiplePropertiesPerLine": true }],
     "object-shorthand": "off",
+    "one-var": "off",
     "padded-blocks": "off",
+    "prefer-const": "off",
+    "prefer-destructuring": ["error", { "AssignmentExpression": {"array": false}}],
     "prefer-template": "off",
+    "quotes": ["error", "single", { "allowTemplateLiterals": true }],
+    "quote-props": "off",
     "require-jsdoc": "off",
     "sort-imports": "off",
     "sort-keys": "off",
diff --git a/src/actions/command.js b/src/actions/command.js
index 03f1e83..3e6eadb 100644
--- a/src/actions/command.js
+++ b/src/actions/command.js
@@ -3,36 +3,39 @@ import * as consoleActions from './console';
 
 const normalizeUrl = (string) => {
   try {
-    return new URL(string).href
+    return new URL(string).href;
   } catch (e) {
     return 'http://' + string;
   }
-}
+};
 
 const openCommand = (url) => {
-  return browser.tabs.query({ active: true, currentWindow: true }).then((tabs) => {
-    if (tabs.length > 0) {
-      return browser.tabs.update(tabs[0].id, { url: url });
+  return browser.tabs.query({
+    active: true, currentWindow: true
+  }).then((gotTabs) => {
+    if (gotTabs.length > 0) {
+      return browser.tabs.update(gotTabs[0].id, { url: url });
     }
   });
-}
+};
 
 const tabopenCommand = (url) => {
   return browser.tabs.create({ url: url });
-}
+};
 
 const bufferCommand = (keywords) => {
-  return browser.tabs.query({ active: true, currentWindow: true }).then((tabss) => {
-    if (tabss.length > 0) {
+  return browser.tabs.query({
+    active: true, currentWindow: true
+  }).then((gotTabs) => {
+    if (gotTabs.length > 0) {
       if (isNaN(keywords)) {
-        return tabs.selectByKeyword(tabss[0], keywords);
-      } else {
-        let index = parseInt(keywords, 10) - 1;
-        return tabs.selectAt(index);
+        return tabs.selectByKeyword(gotTabs[0], keywords);
       }
+      let index = parseInt(keywords, 10) - 1;
+      return tabs.selectAt(index);
     }
   });
-}
+};
 
 const doCommand = (name, remaining) => {
   switch (name) {
@@ -46,39 +49,43 @@ const doCommand = (name, remaining) => {
     return bufferCommand(remaining);
   }
   throw new Error(name + ' command is not defined');
-}
+};
 
 const getCompletions = (command, keywords) => {
   switch (command) {
   case 'buffer':
-    return tabs.getCompletions(keywords).then((tabs) => {
-      let items = tabs.map((tab) => {
+    return tabs.getCompletions(keywords).then((gotTabs) => {
+      let items = gotTabs.map((tab) => {
         return {
           caption: tab.title,
           content: tab.title,
           url: tab.url,
           icon: tab.favIconUrl
-        }
+        };
       });
-      return [{
-        name: "Buffers",
-        items: items
-      }];
+      return [
+        {
+          name: 'Buffers',
+          items: items
+        }
+      ];
     });
   }
   return Promise.resolve([]);
 };
 
-export function exec(line) {
+const exec = (line) => {
   let name = line.split(' ')[0];
   let remaining = line.replace(name + ' ', '');
   return doCommand(name, remaining).then(() => {
     return consoleActions.hide();
   });
-}
+};
 
-export function complete(line) {
+const complete = (line) => {
   let command = line.split(' ', 1)[0];
   let keywords = line.replace(command + ' ', '');
   return getCompletions(command, keywords).then(consoleActions.setCompletions);
-}
+};
+
+export { exec, complete };
diff --git a/src/actions/console.js b/src/actions/console.js
index 99a46e8..e0ec631 100644
--- a/src/actions/console.js
+++ b/src/actions/console.js
@@ -1,28 +1,30 @@
 import actions from '../actions';
 
-export function showCommand(text) {
+const showCommand = (text) => {
   return {
     type: actions.CONSOLE_SHOW_COMMAND,
     text: text
   };
-}
+};
 
-export function setCompletions(completions) {
-  return { 
+const setCompletions = (completions) => {
+  return {
     type: actions.CONSOLE_SET_COMPLETIONS,
     completions: completions
   };
-}
+};
 
-export function showError(text) {
+const showError = (text) => {
   return {
     type: actions.CONSOLE_SHOW_ERROR,
     text: text
   };
-}
+};
 
-export function hide() {
-  return { 
+const hide = () => {
+  return {
     type: actions.CONSOLE_HIDE
   };
-}
+};
+
+export { showCommand, setCompletions, showError, hide };
diff --git a/src/actions/input.js b/src/actions/input.js
index c72b9e0..07948a1 100644
--- a/src/actions/input.js
+++ b/src/actions/input.js
@@ -1,15 +1,17 @@
 import actions from '../actions';
 
-export function keyPress(code, ctrl) {
+const keyPress = (code, ctrl) => {
   return {
     type: actions.INPUT_KEY_PRESS,
     code,
     ctrl
   };
-}
+};
 
-export function clearKeys() {
+const clearKeys = () => {
   return {
     type: actions.INPUT_CLEAR_KEYS
-  }
-}
+  };
+};
+
+export { keyPress, clearKeys };
diff --git a/src/actions/operation.js b/src/actions/operation.js
index e589b89..b0d67f0 100644
--- a/src/actions/operation.js
+++ b/src/actions/operation.js
@@ -1,10 +1,10 @@
 import operations from '../operations';
-import messages  from '../messages';
+import messages from '../messages';
 import * as consoleActions from './console';
 import * as tabs from '../background/tabs';
 import * as zooms from '../background/zooms';
 
-export function exec(operation, tab) {
+const exec = (operation, tab) => {
   switch (operation.type) {
   case operations.TABS_CLOSE:
     return tabs.closeTab(tab.id);
@@ -28,9 +28,8 @@ export function exec(operation, tab) {
     if (operations.alter) {
       // alter url
       return consoleActions.showCommand('open ' + tab.url);
-    } else {
-      return consoleActions.showCommand('open ');
     }
+    return consoleActions.showCommand('open ');
   case operations.COMMAND_BUFFER:
     return consoleActions.showCommand('buffer ');
   default:
@@ -39,5 +38,6 @@ export function exec(operation, tab) {
       operation
     });
   }
-}
+};
 
+export { exec };
diff --git a/src/background/index.js b/src/background/index.js
index ef1b881..a4217c1 100644
--- a/src/background/index.js
+++ b/src/background/index.js
@@ -5,9 +5,10 @@ import * as commandActions from '../actions/command';
 import * as consoleActions from '../actions/console';
 import reducers from '../reducers';
 import messages from '../messages';
-import * as store from '../store'
+import * as store from '../store';
 
 let prevInput = [];
+
 const backgroundStore = store.createStore(reducers, (e, sender) => {
   console.error('Vim-Vixen:', e);
   if (sender) {
@@ -15,9 +16,9 @@ const backgroundStore = store.createStore(reducers, (e, sender) => {
   }
 });
 backgroundStore.subscribe((sender) => {
-  let currentInput = backgroundStore.getState().input
+  let currentInput = backgroundStore.getState().input;
   if (JSON.stringify(prevInput) === JSON.stringify(currentInput)) {
-    return
+    return;
   }
   prevInput = currentInput;
 
@@ -39,13 +40,14 @@ backgroundStore.subscribe((sender) => {
 
 const keyQueueChanged = (state, sender) => {
   let prefix = keys.asKeymapChars(state.input.keys);
-  let matched = Object.keys(keys.defaultKeymap).filter((keys) => {
-    return keys.startsWith(prefix);
+  let matched = Object.keys(keys.defaultKeymap).filter((keyStr) => {
+    return keyStr.startsWith(prefix);
   });
-  if (matched.length == 0) {
+  if (matched.length === 0) {
     backgroundStore.dispatch(inputActions.clearKeys(), sender);
     return Promise.resolve();
-  } else if (matched.length > 1 || matched.length === 1 && prefix !== matched[0]) {
+  } else if (matched.length > 1 ||
+    matched.length === 1 && prefix !== matched[0]) {
     return Promise.resolve();
   }
   let action = keys.defaultKeymap[matched];
@@ -56,15 +58,19 @@ const keyQueueChanged = (state, sender) => {
 const handleMessage = (message, sender) => {
   switch (message.type) {
   case messages.KEYDOWN:
-    return backgroundStore.dispatch(inputActions.keyPress(message.code, message.ctrl), sender);
+    return backgroundStore.dispatch(
+      inputActions.keyPress(message.code, message.ctrl), sender);
   case messages.CONSOLE_BLURRED:
-    return backgroundStore.dispatch(consoleActions.hide(), sender);
+    return backgroundStore.dispatch(
+      consoleActions.hide(), sender);
   case messages.CONSOLE_ENTERED:
-    return backgroundStore.dispatch(commandActions.exec(message.text), sender);
+    return backgroundStore.dispatch(
+      commandActions.exec(message.text), sender);
   case messages.CONSOLE_CHANGEED:
-    return backgroundStore.dispatch(commandActions.complete(message.text), sender);
+    return backgroundStore.dispatch(
+      commandActions.complete(message.text), sender);
   }
-}
+};
 
 browser.runtime.onMessage.addListener((message, sender) => {
   try {
diff --git a/src/background/keys.js b/src/background/keys.js
index 8d75aba..9121e0f 100644
--- a/src/background/keys.js
+++ b/src/background/keys.js
@@ -30,28 +30,26 @@ const defaultKeymap = {
   'F': { type: operations.FOLLOW_START, newTab: true },
   'H': { type: operations.HISTORY_PREV },
   'L': { type: operations.HISTORY_NEXT },
-}
+};
 
 const asKeymapChars = (keys) => {
   return keys.map((k) => {
     let c = String.fromCharCode(k.code);
     if (k.ctrl) {
       return '<C-' + c.toUpperCase() + '>';
-    } else {
-      return c
     }
+    return c;
   }).join('');
-}
+};
 
 const asCaretChars = (keys) => {
   return keys.map((k) => {
     let c = String.fromCharCode(k.code);
     if (k.ctrl) {
       return '^' + c.toUpperCase();
-    } else {
-      return c;
     }
+    return c;
   }).join('');
-}
+};
 
 export { defaultKeymap, asKeymapChars, asCaretChars };
diff --git a/src/background/tabs.js b/src/background/tabs.js
index bd69b4b..32f71ba 100644
--- a/src/background/tabs.js
+++ b/src/background/tabs.js
@@ -12,9 +12,8 @@ const reopenTab = () => {
     let session = sessions[0];
     if (session.tab) {
       return browser.sessions.restore(session.tab.sessionId);
-    } else {
-      return browser.sessions.restore(session.window.sessionId);
     }
+    return browser.sessions.restore(session.window.sessionId);
   });
 };
 
@@ -24,20 +23,20 @@ const selectAt = (index) => {
       return;
     }
     if (index < 0 || tabs.length <= index) {
-      throw new RangeError(`tab ${index} does not exist`)
+      throw new RangeError(`tab ${index} does not exist`);
     }
     let id = tabs[index].id;
-    return browser.tabs.update(id, { active: true })
+    return browser.tabs.update(id, { active: true });
   });
 };
 
 const selectByKeyword = (current, keyword) => {
   return browser.tabs.query({ currentWindow: true }).then((tabs) => {
     let matched = tabs.filter((t) => {
-      return t.url.includes(keyword) || t.title.includes(keyword)
-    })
+      return t.url.includes(keyword) || t.title.includes(keyword);
+    });
 
-    if (matched.length == 0) {
+    if (matched.length === 0) {
       throw new RangeError('No matching buffer for ' + keyword);
     }
     for (let tab of matched) {
@@ -47,13 +46,13 @@ const selectByKeyword = (current, keyword) => {
     }
     return browser.tabs.update(matched[0].id, { active: true });
   });
-}
+};
 
 const getCompletions = (keyword) => {
   return browser.tabs.query({ currentWindow: true }).then((tabs) => {
     let matched = tabs.filter((t) => {
-      return t.url.includes(keyword) || t.title.includes(keyword)
-    })
+      return t.url.includes(keyword) || t.title.includes(keyword);
+    });
     return matched;
   });
 };
@@ -63,9 +62,9 @@ const selectPrevTab = (current, count) => {
     if (tabs.length < 2) {
       return;
     }
-    let select = (current - count) % tabs.length
+    let select = (current - count) % tabs.length;
     let id = tabs[select].id;
-    return browser.tabs.update(id, { active: true })
+    return browser.tabs.update(id, { active: true });
   });
 };
 
@@ -74,9 +73,9 @@ const selectNextTab = (current, count) => {
     if (tabs.length < 2) {
       return;
     }
-    let select = (current + count + tabs.length) % tabs.length
+    let select = (current + count + tabs.length) % tabs.length;
     let id = tabs[select].id;
-    return browser.tabs.update(id, { active: true })
+    return browser.tabs.update(id, { active: true });
   });
 };
 
@@ -87,4 +86,7 @@ const reload = (current, cache) => {
   );
 };
 
-export { closeTab, reopenTab, selectAt, selectByKeyword, getCompletions, selectPrevTab, selectNextTab, reload };
+export {
+  closeTab, reopenTab, selectAt, selectByKeyword, getCompletions,
+  selectPrevTab, selectNextTab, reload
+};
diff --git a/src/console/completion.js b/src/console/completion.js
index 0c21cb0..4c69afb 100644
--- a/src/console/completion.js
+++ b/src/console/completion.js
@@ -3,15 +3,16 @@ export default class Completion {
     if (typeof completions.length !== 'number') {
       throw new TypeError('completions does not have a length in number');
     }
-    this.completions = completions
+    this.completions = completions;
     this.index = 0;
   }
 
   prev() {
-    if (this.completions.length === 0) {
+    let length = this.completions.length;
+    if (length === 0) {
       return null;
     }
-    this.index = (this.index + this.completions.length - 1) % this.completions.length
+    this.index = (this.index + length - 1) % length;
     return this.completions[this.index];
   }
 
@@ -20,7 +21,7 @@ export default class Completion {
       return null;
     }
     let item = this.completions[this.index];
-    this.index = (this.index + 1) % this.completions.length
+    this.index = (this.index + 1) % this.completions.length;
     return item;
   }
 }
diff --git a/src/console/console.js b/src/console/console.js
index d1547b8..4471446 100644
--- a/src/console/console.js
+++ b/src/console/console.js
@@ -3,10 +3,10 @@ import Completion from './completion';
 import messages from '../messages';
 
 // TODO consider object-oriented
-var prevValue = "";
-var completion = null;
-var completionOrigin = "";
-var prevState = {};
+let prevValue = '';
+let completion = null;
+let completionOrigin = '';
+let prevState = {};
 
 const handleBlur = () => {
   return browser.runtime.sendMessage({
@@ -14,6 +14,20 @@ const handleBlur = () => {
   });
 };
 
+const selectCompletion = (target) => {
+  let container = window.document.querySelector('#vimvixen-console-completion');
+  Array.prototype.forEach.call(container.children, (ele) => {
+    if (!ele.classList.contains('vimvixen-console-completion-item')) {
+      return;
+    }
+    if (ele === target) {
+      ele.classList.add('vimvixen-completion-selected');
+    } else {
+      ele.classList.remove('vimvixen-completion-selected');
+    }
+  });
+};
+
 const completeNext = () => {
   if (!completion) {
     return;
@@ -27,7 +41,7 @@ const completeNext = () => {
   input.value = completionOrigin + ' ' + item[0].content;
 
   selectCompletion(item[1]);
-}
+};
 
 const completePrev = () => {
   if (!completion) {
@@ -42,12 +56,12 @@ const completePrev = () => {
   input.value = completionOrigin + ' ' + item[0].content;
 
   selectCompletion(item[1]);
-}
+};
 
 const handleKeydown = (e) => {
   let input = window.document.querySelector('#vimvixen-console-command-input');
 
-  switch(e.keyCode) {
+  switch (e.keyCode) {
   case KeyboardEvent.DOM_VK_ESCAPE:
     return input.blur();
   case KeyboardEvent.DOM_VK_RETURN:
@@ -92,17 +106,17 @@ const createCompletionTitle = (text) => {
   let li = document.createElement('li');
   li.className = 'vimvixen-console-completion-title';
   li.textContent = text;
-  return li
-}
+  return li;
+};
 
 const createCompletionItem = (icon, caption, url) => {
   let captionEle = document.createElement('span');
   captionEle.className = 'vimvixen-console-completion-item-caption';
-  captionEle.textContent = caption
+  captionEle.textContent = caption;
 
   let urlEle = document.createElement('span');
   urlEle.className = 'vimvixen-console-completion-item-url';
-  urlEle.textContent = url
+  urlEle.textContent = url;
 
   let li = document.createElement('li');
   li.style.backgroundImage = 'url(' + icon + ')';
@@ -110,24 +124,11 @@ const createCompletionItem = (icon, caption, url) => {
   li.append(captionEle);
   li.append(urlEle);
   return li;
-}
-
-const selectCompletion = (target) => {
-  let container  = window.document.querySelector('#vimvixen-console-completion');
-  Array.prototype.forEach.call(container.children, (ele) => {
-    if (!ele.classList.contains('vimvixen-console-completion-item')) {
-      return;
-    }
-    if (ele === target) {
-      ele.classList.add('vimvixen-completion-selected');
-    } else {
-      ele.classList.remove('vimvixen-completion-selected');
-    }
-  });
 };
 
 const updateCompletions = (completions) => {
-  let completionsContainer  = window.document.querySelector('#vimvixen-console-completion');
+  let completionsContainer =
+    window.document.querySelector('#vimvixen-console-completion');
   let input = window.document.querySelector('#vimvixen-console-command-input');
 
   completionsContainer.innerHTML = '';
@@ -148,7 +149,7 @@ const updateCompletions = (completions) => {
 
   completion = new Completion(pairs);
   completionOrigin = input.value.split(' ')[0];
-}
+};
 
 const update = (state) => {
   let error = window.document.querySelector('#vimvixen-console-error');
@@ -163,12 +164,13 @@ const update = (state) => {
     input.value = state.commandText;
     input.focus();
   }
-  if (JSON.stringify(state.completions) !== JSON.stringify(prevState.completions)) {
+  if (JSON.stringify(state.completions) !==
+    JSON.stringify(prevState.completions)) {
     updateCompletions(state.completions);
   }
 
   prevState = state;
-}
+};
 
 browser.runtime.onMessage.addListener((action) => {
   if (action.type === messages.STATE_UPDATE) {
diff --git a/src/console/frames.js b/src/console/frames.js
index ec1e38c..3f06466 100644
--- a/src/console/frames.js
+++ b/src/console/frames.js
@@ -8,11 +8,11 @@ const initialize = (doc) => {
   doc.body.append(iframe);
 
   return iframe;
-}
+};
 
 const blur = (doc) => {
   let iframe = doc.getElementById('vimvixen-console-frame');
   iframe.blur();
-}
+};
 
 export { initialize, blur };
diff --git a/src/content/follow.js b/src/content/follow.js
index ffa16b9..5abeee0 100644
--- a/src/content/follow.js
+++ b/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') {
diff --git a/src/content/hint-key-producer.js b/src/content/hint-key-producer.js
index 8064afb..14b23b6 100644
--- a/src/content/hint-key-producer.js
+++ b/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);
diff --git a/src/content/hint.js b/src/content/hint.js
index fabf725..c75ca8b 100644
--- a/src/content/hint.js
+++ b/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';
diff --git a/src/content/histories.js b/src/content/histories.js
index 2e34dc6..9c5665d 100644
--- a/src/content/histories.js
+++ b/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 };
diff --git a/src/content/index.js b/src/content/index.js
index 5d3735c..91f5420 100644
--- a/src/content/index.js
+++ b/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) {
diff --git a/src/content/scrolls.js b/src/content/scrolls.js
index bc88e43..b1cea6f 100644
--- a/src/content/scrolls.js
+++ b/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
+};
diff --git a/src/operations/index.js b/src/operations/index.js
index 05c7d78..c2db007 100644
--- a/src/operations/index.js
+++ b/src/operations/index.js
@@ -1,5 +1,5 @@
 export default {
-  // command
+  // Command
   COMMAND_OPEN: 'cmd.open',
   COMMAND_TABS_OPEN: 'cmd.tabs.open',
   COMMAND_BUFFER: 'cmd.buffer',
@@ -14,7 +14,7 @@ export default {
   HISTORY_PREV: 'history.prev',
   HISTORY_NEXT: 'history.next',
 
-  // background
+  // Background
   TABS_CLOSE: 'tabs.close',
   TABS_REOPEN: 'tabs.reopen',
   TABS_PREV: 'tabs.prev',
@@ -23,4 +23,4 @@ export default {
   ZOOM_IN: 'zoom.in',
   ZOOM_OUT: 'zoom.out',
   ZOOM_NEUTRAL: 'zoom.neutral',
-}
+};
diff --git a/src/reducers/console.js b/src/reducers/console.js
index 27ccdc9..5c49c3b 100644
--- a/src/reducers/console.js
+++ b/src/reducers/console.js
@@ -12,7 +12,7 @@ export default function reducer(state = defaultState, action = {}) {
   switch (action.type) {
   case actions.CONSOLE_SHOW_COMMAND:
     return Object.assign({}, state, {
-      commandShown: true, 
+      commandShown: true,
       commandText: action.text,
       errorShown: false,
       completions: []
diff --git a/src/reducers/input.js b/src/reducers/input.js
index 25ff1a3..eb7ff24 100644
--- a/src/reducers/input.js
+++ b/src/reducers/input.js
@@ -8,10 +8,12 @@ export default function reducer(state = defaultState, action = {}) {
   switch (action.type) {
   case actions.INPUT_KEY_PRESS:
     return Object.assign({}, state, {
-      keys: state.keys.concat([{
-        code: action.code,
-        ctrl: action.ctrl
-      }])
+      keys: state.keys.concat([
+        {
+          code: action.code,
+          ctrl: action.ctrl
+        }
+      ])
     });
   case actions.INPUT_CLEAR_KEYS:
     return Object.assign({}, state, {
diff --git a/src/store/index.js b/src/store/index.js
index 2d08296..2fafdf1 100644
--- a/src/store/index.js
+++ b/src/store/index.js
@@ -24,7 +24,7 @@ class Store {
         this.catcher(e, sender);
       }
     }
-    return action
+    return action;
   }
 
   getState() {
@@ -46,6 +46,8 @@ class Store {
 
 const empty = () => {};
 
-export function createStore(reducer, catcher = empty) {
+const createStore = (reducer, catcher = empty) => {
   return new Store(reducer, catcher);
-}
+};
+
+export { createStore };