npm run lint:fix

32 files changed, 145 insertions, 145 deletions

diff --git a/src/content/Application.ts b/src/content/Application.ts
index 1677655..cfa01fd 100644
--- a/src/content/Application.ts
+++ b/src/content/Application.ts
@@ -111,7 +111,7 @@ export default class Application {
       }
     });
 
-    let inputDriver = new InputDriver(window.document.body);
+    const inputDriver = new InputDriver(window.document.body);
     inputDriver.onKey(key => this.followKeyController.press(key));
     inputDriver.onKey(key => this.markKeyController.press(key));
     inputDriver.onKey(key => this.keymapController.press(key));
diff --git a/src/content/InputDriver.ts b/src/content/InputDriver.ts
index bc184d2..cf28205 100644
--- a/src/content/InputDriver.ts
+++ b/src/content/InputDriver.ts
@@ -25,7 +25,7 @@ const modifiedKeyName = (name: string): string => {
 
 // visible for testing
 export const keyFromKeyboardEvent = (e: KeyboardEvent): Key => {
-  let key = modifiedKeyName(e.key);
+  const key = modifiedKeyName(e.key);
   let shift = e.shiftKey;
   if (key.length === 1 && key.toUpperCase() === key.toLowerCase()) {
     // make shift false for symbols to enable key bindings by symbold keys.
@@ -83,7 +83,7 @@ export default class InputDriver {
 
   // eslint-disable-next-line max-statements
   private capture(e: KeyboardEvent) {
-    let target = e.target;
+    const target = e.target;
     if (!(target instanceof HTMLElement)) {
       return;
     }
@@ -98,9 +98,9 @@ export default class InputDriver {
       return;
     }
 
-    let key = keyFromKeyboardEvent(e);
-    for (let listener of this.onKeyListeners) {
-      let stop = listener(key);
+    const key = keyFromKeyboardEvent(e);
+    for (const listener of this.onKeyListeners) {
+      const stop = listener(key);
       if (stop) {
         e.preventDefault();
         e.stopPropagation();
diff --git a/src/content/MessageListener.ts b/src/content/MessageListener.ts
index d035825..e1f7c75 100644
--- a/src/content/MessageListener.ts
+++ b/src/content/MessageListener.ts
@@ -9,7 +9,7 @@ export default class MessageListener {
     listener: (msg: Message, sender: Window) => void,
   ) {
     window.addEventListener('message', (event: MessageEvent) => {
-      let sender = event.source;
+      const sender = event.source;
       if (!(sender instanceof Window)) {
         return;
       }
diff --git a/src/content/client/FindClient.ts b/src/content/client/FindClient.ts
index af0b427..8b2aca4 100644
--- a/src/content/client/FindClient.ts
+++ b/src/content/client/FindClient.ts
@@ -8,7 +8,7 @@ export default interface FindClient {
 
 export class FindClientImpl implements FindClient {
   async getGlobalLastKeyword(): Promise<string | null> {
-    let keyword = await browser.runtime.sendMessage({
+    const keyword = await browser.runtime.sendMessage({
       type: messages.FIND_GET_KEYWORD,
     });
     return keyword as string;
diff --git a/src/content/client/SettingClient.ts b/src/content/client/SettingClient.ts
index fc62720..f89f3cd 100644
--- a/src/content/client/SettingClient.ts
+++ b/src/content/client/SettingClient.ts
@@ -7,7 +7,7 @@ export default interface SettingClient {
 
 export class SettingClientImpl {
   async load(): Promise<Settings> {
-    let settings = await browser.runtime.sendMessage({
+    const settings = await browser.runtime.sendMessage({
       type: messages.SETTINGS_QUERY,
     });
     return Settings.fromJSON(settings);
diff --git a/src/content/controllers/AddonEnabledController.ts b/src/content/controllers/AddonEnabledController.ts
index bae95bf..59b45fa 100644
--- a/src/content/controllers/AddonEnabledController.ts
+++ b/src/content/controllers/AddonEnabledController.ts
@@ -12,7 +12,7 @@ export default class AddonEnabledController {
   getAddonEnabled(
     _message: messages.AddonEnabledQueryMessage,
   ): Promise<boolean> {
-    let enabled = this.addonEnabledUseCase.getEnabled();
+    const enabled = this.addonEnabledUseCase.getEnabled();
     return Promise.resolve(enabled);
   }
 }
diff --git a/src/content/controllers/KeymapController.ts b/src/content/controllers/KeymapController.ts
index 452e3d4..f9c2545 100644
--- a/src/content/controllers/KeymapController.ts
+++ b/src/content/controllers/KeymapController.ts
@@ -32,7 +32,7 @@ export default class KeymapController {
 
   // eslint-disable-next-line complexity, max-lines-per-function
   press(key: Key): boolean {
-    let nextOp = this.keymapUseCase.nextOps(key);
+    const nextOp = this.keymapUseCase.nextOps(key);
     if (nextOp === null) {
       return false;
     }
diff --git a/src/content/controllers/SettingController.ts b/src/content/controllers/SettingController.ts
index e1c7f01..9124188 100644
--- a/src/content/controllers/SettingController.ts
+++ b/src/content/controllers/SettingController.ts
@@ -14,9 +14,9 @@ export default class SettingController {
 
   async initSettings(): Promise<void> {
     try {
-      let current = await this.settingUseCase.reload();
-      let url = new URL(window.location.href);
-      let disabled = current.blacklist.includesEntireBlacklist(url);
+      const current = await this.settingUseCase.reload();
+      const url = new URL(window.location.href);
+      const disabled = current.blacklist.includesEntireBlacklist(url);
       if (disabled) {
         this.addonEnabledUseCase.disable();
       } else {
diff --git a/src/content/domains/KeySequence.ts b/src/content/domains/KeySequence.ts
index 4534b60..cf59125 100644
--- a/src/content/domains/KeySequence.ts
+++ b/src/content/domains/KeySequence.ts
@@ -38,7 +38,7 @@ export default class KeySequence {
     if (nonDigitAt === -1) {
       nonDigitAt = this.keys.length;
     }
-    let digits = this.keys.slice(0, nonDigitAt)
+    const digits = this.keys.slice(0, nonDigitAt)
       .map(key => key.key)
       .join('');
     return Number(digits);
@@ -53,7 +53,7 @@ export default class KeySequence {
   }
 
   splitNumericPrefix(): [KeySequence, KeySequence] {
-    let nonDigitIndex = this.keys.findIndex(key => !key.isDigit());
+    const nonDigitIndex = this.keys.findIndex(key => !key.isDigit());
     if (nonDigitIndex === -1) {
       return [this, new KeySequence([])];
     }
@@ -73,7 +73,7 @@ export default class KeySequence {
 
       let nextPos = 1;
       if (remaining.startsWith('<')) {
-        let ltPos = remaining.indexOf('>');
+        const ltPos = remaining.indexOf('>');
         if (ltPos > 0) {
           nextPos = ltPos + 1;
         }
@@ -85,7 +85,7 @@ export default class KeySequence {
       );
     };
 
-    let data = fromMapKeysRecursive(keys, []);
+    const data = fromMapKeysRecursive(keys, []);
     return new KeySequence(data);
   }
 }
diff --git a/src/content/hint-key-producer.ts b/src/content/hint-key-producer.ts
index 935394e..3c9482f 100644
--- a/src/content/hint-key-producer.ts
+++ b/src/content/hint-key-producer.ts
@@ -19,14 +19,14 @@ export default class HintKeyProducer {
   }
 
   private increment(): void {
-    let max = this.charset.length - 1;
+    const max = this.charset.length - 1;
     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;
+    const len = this.charset.length;
     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;
diff --git a/src/content/index.ts b/src/content/index.ts
index 5b9b92c..176a157 100644
--- a/src/content/index.ts
+++ b/src/content/index.ts
@@ -11,10 +11,10 @@ if (window.self === window.top) {
 }
 
 try {
-  let app = container.resolve(Application);
+  const app = container.resolve(Application);
   app.run();
 } catch (e) { console.error(e); }
 
-let style = window.document.createElement('style');
+const style = window.document.createElement('style');
 style.textContent = consoleFrameStyle;
 window.document.head.appendChild(style);
diff --git a/src/content/presenters/ConsoleFramePresenter.ts b/src/content/presenters/ConsoleFramePresenter.ts
index 62db2bb..63c78fb 100644
--- a/src/content/presenters/ConsoleFramePresenter.ts
+++ b/src/content/presenters/ConsoleFramePresenter.ts
@@ -6,7 +6,7 @@ export default interface ConsoleFramePresenter {
 
 export class ConsoleFramePresenterImpl implements ConsoleFramePresenter {
   initialize(): void {
-    let iframe = document.createElement('iframe');
+    const iframe = document.createElement('iframe');
     iframe.src = browser.runtime.getURL('build/console.html');
     iframe.id = 'vimvixen-console-frame';
     iframe.className = 'vimvixen-console-frame';
@@ -14,7 +14,7 @@ export class ConsoleFramePresenterImpl implements ConsoleFramePresenter {
   }
 
   blur(): void {
-    let ele = document.getElementById('vimvixen-console-frame');
+    const ele = document.getElementById('vimvixen-console-frame');
     if (!ele) {
       throw new Error('console frame not created');
     }
diff --git a/src/content/presenters/FindPresenter.ts b/src/content/presenters/FindPresenter.ts
index f171d2f..98d8088 100644
--- a/src/content/presenters/FindPresenter.ts
+++ b/src/content/presenters/FindPresenter.ts
@@ -26,13 +26,13 @@ declare var window: MyWindow;
 
 export class FindPresenterImpl implements FindPresenter {
   find(keyword: string, backwards: boolean): boolean {
-    let caseSensitive = false;
-    let wrapScan = true;
+    const caseSensitive = false;
+    const wrapScan = true;
 
 
     // NOTE: aWholeWord dows not implemented, and aSearchInFrames does not work
     // because of same origin policy
-    let found = window.find(keyword, caseSensitive, backwards, wrapScan);
+    const found = window.find(keyword, caseSensitive, backwards, wrapScan);
     if (found) {
       return found;
     }
@@ -42,7 +42,7 @@ export class FindPresenterImpl implements FindPresenter {
   }
 
   clearSelection(): void {
-    let sel = window.getSelection();
+    const sel = window.getSelection();
     if (sel) {
       sel.removeAllRanges();
     }
diff --git a/src/content/presenters/FocusPresenter.ts b/src/content/presenters/FocusPresenter.ts
index 7e20cd6..842c41e 100644
--- a/src/content/presenters/FocusPresenter.ts
+++ b/src/content/presenters/FocusPresenter.ts
@@ -6,10 +6,10 @@ export default interface FocusPresenter {
 
 export class FocusPresenterImpl implements FocusPresenter {
   focusFirstElement(): boolean {
-    let inputTypes = ['email', 'number', 'search', 'tel', 'text', 'url'];
-    let inputSelector = inputTypes.map(type => `input[type=${type}]`).join(',');
-    let targets = window.document.querySelectorAll(inputSelector + ',textarea');
-    let target = Array.from(targets).find(doms.isVisible);
+    const inputTypes = ['email', 'number', 'search', 'tel', 'text', 'url'];
+    const inputSelector = inputTypes.map(type => `input[type=${type}]`).join(',');
+    const targets = window.document.querySelectorAll(inputSelector + ',textarea');
+    const target = Array.from(targets).find(doms.isVisible);
     if (target instanceof HTMLInputElement) {
       target.focus();
       return true;
diff --git a/src/content/presenters/FollowPresenter.ts b/src/content/presenters/FollowPresenter.ts
index 0132621..fef8140 100644
--- a/src/content/presenters/FollowPresenter.ts
+++ b/src/content/presenters/FollowPresenter.ts
@@ -23,12 +23,12 @@ const inViewport = (
   viewSize: Size,
   framePosition: Point,
 ): boolean => {
-  let {
+  const {
     top, left, bottom, right
   } = doms.viewportRect(element);
-  let doc = win.document;
-  let frameWidth = doc.documentElement.clientWidth;
-  let frameHeight = doc.documentElement.clientHeight;
+  const doc = win.document;
+  const frameWidth = doc.documentElement.clientWidth;
+  const frameHeight = doc.documentElement.clientHeight;
 
   if (right < 0 || bottom < 0 || top > frameHeight || left > frameWidth) {
     // out of frame
@@ -47,10 +47,10 @@ const isAriaHiddenOrAriaDisabled = (win: Window, element: Element): boolean => {
   if (!element || win.document.documentElement === element) {
     return false;
   }
-  for (let attr of ['aria-hidden', 'aria-disabled']) {
-    let value = element.getAttribute(attr);
+  for (const attr of ['aria-hidden', 'aria-disabled']) {
+    const value = element.getAttribute(attr);
     if (value !== null) {
-      let hidden = value.toLowerCase();
+      const hidden = value.toLowerCase();
       if (hidden === '' || hidden === 'true') {
         return true;
       }
@@ -79,15 +79,15 @@ export class FollowPresenterImpl implements FollowPresenter {
   }
 
   getTargetCount(viewSize: Size, framePosition: Point): number {
-    let targets = this.getTargets(viewSize, framePosition);
+    const targets = this.getTargets(viewSize, framePosition);
     return targets.length;
   }
 
   createHints(viewSize: Size, framePosition: Point, tags: string[]): void {
-    let targets = this.getTargets(viewSize, framePosition);
-    let min = Math.min(targets.length, tags.length);
+    const targets = this.getTargets(viewSize, framePosition);
+    const min = Math.min(targets.length, tags.length);
     for (let i = 0; i < min; ++i) {
-      let target = targets[i];
+      const target = targets[i];
       if (target instanceof HTMLAnchorElement ||
         target instanceof HTMLAreaElement) {
         this.hints.push(new LinkHint(target, tags[i]));
@@ -98,8 +98,8 @@ export class FollowPresenterImpl implements FollowPresenter {
   }
 
   filterHints(prefix: string): void {
-    let shown = this.hints.filter(h => h.getTag().startsWith(prefix));
-    let hidden = this.hints.filter(h => !h.getTag().startsWith(prefix));
+    const shown = this.hints.filter(h => h.getTag().startsWith(prefix));
+    const hidden = this.hints.filter(h => !h.getTag().startsWith(prefix));
 
     shown.forEach(h => h.show());
     hidden.forEach(h => h.hide());
@@ -115,9 +115,9 @@ export class FollowPresenterImpl implements FollowPresenter {
   }
 
   private getTargets(viewSize: Size, framePosition: Point): HTMLElement[] {
-    let all = window.document.querySelectorAll(TARGET_SELECTOR);
-    let filtered = Array.prototype.filter.call(all, (element: HTMLElement) => {
-      let style = window.getComputedStyle(element);
+    const all = window.document.querySelectorAll(TARGET_SELECTOR);
+    const filtered = Array.prototype.filter.call(all, (element: HTMLElement) => {
+      const style = window.getComputedStyle(element);
 
       // AREA's 'display' in Browser style is 'none'
       return (element.tagName === 'AREA' || style.display !== 'none') &&
diff --git a/src/content/presenters/Hint.ts b/src/content/presenters/Hint.ts
index 60c0f4c..44b8185 100644
--- a/src/content/presenters/Hint.ts
+++ b/src/content/presenters/Hint.ts
@@ -6,7 +6,7 @@ interface Point {
 }
 
 const hintPosition = (element: Element): Point => {
-  let { left, top, right, bottom } = doms.viewportRect(element);
+  const { left, top, right, bottom } = doms.viewportRect(element);
 
   if (element.tagName !== 'AREA') {
     return { x: left, y: top };
@@ -26,15 +26,15 @@ export default abstract class Hint {
   constructor(target: HTMLElement, tag: string) {
     this.tag = tag;
 
-    let doc = target.ownerDocument;
+    const doc = target.ownerDocument;
     if (doc === null) {
       throw new TypeError('ownerDocument is null');
     }
 
-    let { x, y } = hintPosition(target);
-    let { scrollX, scrollY } = window;
+    const { x, y } = hintPosition(target);
+    const { scrollX, scrollY } = window;
 
-    let hint = doc.createElement('span');
+    const hint = doc.createElement('span');
     hint.className = 'vimvixen-hint';
     hint.textContent = tag;
     hint.style.left = x + scrollX + 'px';
@@ -95,7 +95,7 @@ export class InputHint extends Hint {
   }
 
   activate(): void {
-    let target = this.target;
+    const target = this.target;
     switch (target.tagName.toLowerCase()) {
     case 'input':
       switch ((target as HTMLInputElement).type) {
diff --git a/src/content/presenters/NavigationPresenter.ts b/src/content/presenters/NavigationPresenter.ts
index 11d96ec..951e62a 100644
--- a/src/content/presenters/NavigationPresenter.ts
+++ b/src/content/presenters/NavigationPresenter.ts
@@ -49,7 +49,7 @@ export class NavigationPresenterImpl implements NavigationPresenter {
 
   // Code common to linkPrev and linkNext which navigates to the specified page.
   private linkRel(rel: 'prev' | 'next'): void {
-    let link = selectLast<HTMLLinkElement>(`link[rel~=${rel}][href]`);
+    const link = selectLast<HTMLLinkElement>(`link[rel~=${rel}][href]`);
     if (link) {
       window.location.href = link.href;
       return;
@@ -57,7 +57,7 @@ export class NavigationPresenterImpl implements NavigationPresenter {
 
     const pattern = REL_PATTERN[rel];
 
-    let a = selectLast<HTMLAnchorElement>(`a[rel~=${rel}][href]`) ||
+    const a = selectLast<HTMLAnchorElement>(`a[rel~=${rel}][href]`) ||
     // `innerText` is much slower than `textContent`, but produces much better
     // (i.e. less unexpected) results
     selectLast('a[href]', lnk => pattern.test(lnk.innerText));
diff --git a/src/content/presenters/ScrollPresenter.ts b/src/content/presenters/ScrollPresenter.ts
index e83f172..387ab62 100644
--- a/src/content/presenters/ScrollPresenter.ts
+++ b/src/content/presenters/ScrollPresenter.ts
@@ -8,7 +8,7 @@ let scrolling = false;
 let lastTimeoutId: number | null = null;
 
 const isScrollableStyle = (element: Element): boolean => {
-  let { overflowX, overflowY } = window.getComputedStyle(element);
+  const { overflowX, overflowY } = window.getComputedStyle(element);
   return !(overflowX !== 'scroll' && overflowX !== 'auto' &&
     overflowY !== 'scroll' && overflowY !== 'auto');
 };
@@ -27,9 +27,9 @@ const findScrollable = (element: Element): Element | null => {
     return element;
   }
 
-  let children = Array.from(element.children).filter(doms.isVisible);
-  for (let child of children) {
-    let scrollable = findScrollable(child);
+  const children = Array.from(element.children).filter(doms.isVisible);
+  for (const child of children) {
+    const scrollable = findScrollable(child);
     if (scrollable) {
       return scrollable;
     }
@@ -44,7 +44,7 @@ const scrollTarget = () => {
   if (isOverflowed(window.document.body)) {
     return window.document.body;
   }
-  let target = findScrollable(window.document.documentElement);
+  const target = findScrollable(window.document.documentElement);
   if (target) {
     return target;
   }
@@ -79,8 +79,8 @@ class Scroller {
   }
 
   scrollBy(x: number, y: number): void {
-    let left = this.element.scrollLeft + x;
-    let top = this.element.scrollTop + y;
+    const left = this.element.scrollLeft + x;
+    const top = this.element.scrollTop + y;
     this.scrollTo(left, top);
   }
 
@@ -110,12 +110,12 @@ export default interface ScrollPresenter {
 
 export class ScrollPresenterImpl {
   getScroll(): Point {
-    let target = scrollTarget();
+    const target = scrollTarget();
     return { x: target.scrollLeft, y: target.scrollTop };
   }
 
   scrollVertically(count: number, smooth: boolean): void {
-    let target = scrollTarget();
+    const target = scrollTarget();
     let delta = SCROLL_DELTA_Y * count;
     if (scrolling) {
       delta = SCROLL_DELTA_Y * count * 4;
@@ -124,7 +124,7 @@ export class ScrollPresenterImpl {
   }
 
   scrollHorizonally(count: number, smooth: boolean): void {
-    let target = scrollTarget();
+    const target = scrollTarget();
     let delta = SCROLL_DELTA_X * count;
     if (scrolling) {
       delta = SCROLL_DELTA_X * count * 4;
@@ -133,8 +133,8 @@ export class ScrollPresenterImpl {
   }
 
   scrollPages(count: number, smooth: boolean): void {
-    let target = scrollTarget();
-    let height = target.clientHeight;
+    const target = scrollTarget();
+    const height = target.clientHeight;
     let delta = height * count;
     if (scrolling) {
       delta = height * count;
@@ -143,35 +143,35 @@ export class ScrollPresenterImpl {
   }
 
   scrollTo(x: number, y: number, smooth: boolean): void {
-    let target = scrollTarget();
+    const target = scrollTarget();
     new Scroller(target, smooth).scrollTo(x, y);
   }
 
   scrollToTop(smooth: boolean): void {
-    let target = scrollTarget();
-    let x = target.scrollLeft;
-    let y = 0;
+    const target = scrollTarget();
+    const x = target.scrollLeft;
+    const y = 0;
     new Scroller(target, smooth).scrollTo(x, y);
   }
 
   scrollToBottom(smooth: boolean): void {
-    let target = scrollTarget();
-    let x = target.scrollLeft;
-    let y = target.scrollHeight;
+    const target = scrollTarget();
+    const x = target.scrollLeft;
+    const y = target.scrollHeight;
     new Scroller(target, smooth).scrollTo(x, y);
   }
 
   scrollToHome(smooth: boolean): void {
-    let target = scrollTarget();
-    let x = 0;
-    let y = target.scrollTop;
+    const target = scrollTarget();
+    const x = 0;
+    const y = target.scrollTop;
     new Scroller(target, smooth).scrollTo(x, y);
   }
 
   scrollToEnd(smooth: boolean): void {
-    let target = scrollTarget();
-    let x = target.scrollWidth;
-    let y = target.scrollTop;
+    const target = scrollTarget();
+    const x = target.scrollWidth;
+    const y = target.scrollTop;
     new Scroller(target, smooth).scrollTo(x, y);
   }
 }
diff --git a/src/content/repositories/AddonEnabledRepository.ts b/src/content/repositories/AddonEnabledRepository.ts
index 7921bdb..ce3f521 100644
--- a/src/content/repositories/AddonEnabledRepository.ts
+++ b/src/content/repositories/AddonEnabledRepository.ts
@@ -1,4 +1,4 @@
-let enabled: boolean = false;
+let enabled = false;
 
 export default interface AddonEnabledRepository {
   set(on: boolean): void;
diff --git a/src/content/repositories/ClipboardRepository.ts b/src/content/repositories/ClipboardRepository.ts
index a046851..8219835 100644
--- a/src/content/repositories/ClipboardRepository.ts
+++ b/src/content/repositories/ClipboardRepository.ts
@@ -6,7 +6,7 @@ export default interface ClipboardRepository {
 
 export class ClipboardRepositoryImpl {
   read(): string {
-    let textarea = window.document.createElement('textarea');
+    const textarea = window.document.createElement('textarea');
     window.document.body.append(textarea);
 
     textarea.style.position = 'fixed';
@@ -14,8 +14,8 @@ export class ClipboardRepositoryImpl {
     textarea.contentEditable = 'true';
     textarea.focus();
 
-    let ok = window.document.execCommand('paste');
-    let value = textarea.textContent!!;
+    const ok = window.document.execCommand('paste');
+    const value = textarea.textContent!!;
     textarea.remove();
 
     if (!ok) {
@@ -26,7 +26,7 @@ export class ClipboardRepositoryImpl {
   }
 
   write(text: string): void {
-    let input = window.document.createElement('input');
+    const input = window.document.createElement('input');
     window.document.body.append(input);
 
     input.style.position = 'fixed';
@@ -34,7 +34,7 @@ export class ClipboardRepositoryImpl {
     input.value = text;
     input.select();
 
-    let ok = window.document.execCommand('copy');
+    const ok = window.document.execCommand('copy');
     input.remove();
 
     if (!ok) {
diff --git a/src/content/repositories/MarkKeyRepository.ts b/src/content/repositories/MarkKeyRepository.ts
index 0b24af2..18c3e23 100644
--- a/src/content/repositories/MarkKeyRepository.ts
+++ b/src/content/repositories/MarkKeyRepository.ts
@@ -17,7 +17,7 @@ interface Mode {
   jumpMode: boolean;
 }
 
-let current: Mode = {
+const current: Mode = {
   setMode: false,
   jumpMode: false,
 };
diff --git a/src/content/repositories/MarkRepository.ts b/src/content/repositories/MarkRepository.ts
index 678abc4..afa980a 100644
--- a/src/content/repositories/MarkRepository.ts
+++ b/src/content/repositories/MarkRepository.ts
@@ -14,7 +14,7 @@ export class MarkRepositoryImpl implements MarkRepository {
   }
 
   get(key: string): Mark | null {
-    let v = saved[key];
+    const v = saved[key];
     if (!v) {
       return null;
     }
diff --git a/src/content/usecases/AddonEnabledUseCase.ts b/src/content/usecases/AddonEnabledUseCase.ts
index 2d6fa11..608a401 100644
--- a/src/content/usecases/AddonEnabledUseCase.ts
+++ b/src/content/usecases/AddonEnabledUseCase.ts
@@ -23,7 +23,7 @@ export default class AddonEnabledUseCase {
   }
 
   async toggle(): Promise<void> {
-    let current = this.repository.get();
+    const current = this.repository.get();
     await this.setEnabled(!current);
   }
 
diff --git a/src/content/usecases/ClipboardUseCase.ts b/src/content/usecases/ClipboardUseCase.ts
index c8fe719..7f16f68 100644
--- a/src/content/usecases/ClipboardUseCase.ts
+++ b/src/content/usecases/ClipboardUseCase.ts
@@ -16,16 +16,16 @@ export default class ClipboardUseCase {
   }
 
   async yankCurrentURL(): Promise<string> {
-    let url = window.location.href;
+    const url = window.location.href;
     this.repository.write(url);
     await this.consoleClient.info('Yanked ' + url);
     return Promise.resolve(url);
   }
 
   async openOrSearch(newTab: boolean): Promise<void> {
-    let search = this.settingRepository.get().search;
-    let text = this.repository.read();
-    let url = urls.searchUrl(text, search);
+    const search = this.settingRepository.get().search;
+    const text = this.repository.read();
+    const url = urls.searchUrl(text, search);
 
     // TODO: Repeat pasting from clipboard instead of opening a certain url.
     // 'Repeat last' command is implemented in the background script and cannot
diff --git a/src/content/usecases/FindUseCase.ts b/src/content/usecases/FindUseCase.ts
index 88b516c..c6a478f 100644
--- a/src/content/usecases/FindUseCase.ts
+++ b/src/content/usecases/FindUseCase.ts
@@ -19,7 +19,7 @@ export default class FindUseCase {
     if (keyword) {
       this.saveKeyword(keyword);
     } else {
-      let lastKeyword = await this.getKeyword();
+      const lastKeyword = await this.getKeyword();
       if (!lastKeyword) {
         return this.showNoLastKeywordError();
       }
@@ -39,11 +39,11 @@ export default class FindUseCase {
   private async findNextPrev(
     backwards: boolean,
   ): Promise<void> {
-    let keyword = await this.getKeyword();
+    const keyword = await this.getKeyword();
     if (!keyword) {
       return this.showNoLastKeywordError();
     }
-    let found = this.presenter.find(keyword, backwards);
+    const found = this.presenter.find(keyword, backwards);
     if (found) {
       this.consoleClient.info('Pattern found: ' + keyword);
     } else {
diff --git a/src/content/usecases/FollowMasterUseCase.ts b/src/content/usecases/FollowMasterUseCase.ts
index 7d7e875..0e7f394 100644
--- a/src/content/usecases/FollowMasterUseCase.ts
+++ b/src/content/usecases/FollowMasterUseCase.ts
@@ -28,24 +28,24 @@ export default class FollowMasterUseCase {
   }
 
   startFollow(newTab: boolean, background: boolean): void {
-    let hintchars = this.settingRepository.get().properties.hintchars;
+    const hintchars = this.settingRepository.get().properties.hintchars;
     this.producer = new HintKeyProducer(hintchars);
 
     this.followKeyRepository.clearKeys();
     this.followMasterRepository.setCurrentFollowMode(newTab, background);
 
-    let viewWidth = window.top.innerWidth;
-    let viewHeight = window.top.innerHeight;
+    const viewWidth = window.top.innerWidth;
+    const viewHeight = window.top.innerHeight;
     this.followSlaveClientFactory.create(window.top).requestHintCount(
       { width: viewWidth, height: viewHeight },
       { x: 0, y: 0 },
     );
 
-    let frameElements = window.document.querySelectorAll('iframe');
+    const frameElements = window.document.querySelectorAll('iframe');
     for (let i = 0; i < frameElements.length; ++i) {
-      let ele = frameElements[i] as HTMLFrameElement | HTMLIFrameElement;
-      let { left: frameX, top: frameY } = ele.getBoundingClientRect();
-      let client = this.followSlaveClientFactory.create(ele.contentWindow!!);
+      const ele = frameElements[i] as HTMLFrameElement | HTMLIFrameElement;
+      const { left: frameX, top: frameY } = ele.getBoundingClientRect();
+      const client = this.followSlaveClientFactory.create(ele.contentWindow!!);
       client.requestHintCount(
         { width: viewWidth, height: viewHeight },
         { x: frameX, y: frameY },
@@ -55,28 +55,28 @@ export default class FollowMasterUseCase {
 
   // eslint-disable-next-line max-statements
   createSlaveHints(count: number, sender: Window): void {
-    let produced = [];
+    const produced = [];
     for (let i = 0; i < count; ++i) {
-      let tag = this.producer!!.produce();
+      const tag = this.producer!!.produce();
       produced.push(tag);
       this.followMasterRepository.addTag(tag);
     }
 
-    let doc = window.document;
-    let viewWidth = window.innerWidth || doc.documentElement.clientWidth;
-    let viewHeight = window.innerHeight || doc.documentElement.clientHeight;
+    const doc = window.document;
+    const viewWidth = window.innerWidth || doc.documentElement.clientWidth;
+    const viewHeight = window.innerHeight || doc.documentElement.clientHeight;
     let pos = { x: 0, y: 0 };
     if (sender !== window) {
-      let frameElements = window.document.querySelectorAll('iframe');
-      let ele = Array.from(frameElements).find(e => e.contentWindow === sender);
+      const frameElements = window.document.querySelectorAll('iframe');
+      const ele = Array.from(frameElements).find(e => e.contentWindow === sender);
       if (!ele) {
         // elements of the sender is gone
         return;
       }
-      let { left: frameX, top: frameY } = ele.getBoundingClientRect();
+      const { left: frameX, top: frameY } = ele.getBoundingClientRect();
       pos = { x: frameX, y: frameY };
     }
-    let client = this.followSlaveClientFactory.create(sender);
+    const client = this.followSlaveClientFactory.create(sender);
     client.createHints(
       { width: viewWidth, height: viewHeight },
       pos,
@@ -100,8 +100,8 @@ export default class FollowMasterUseCase {
   activate(tag: string): void {
     this.followMasterRepository.clearTags();
 
-    let newTab = this.followMasterRepository.getCurrentNewTabMode();
-    let background = this.followMasterRepository.getCurrentBackgroundMode();
+    const newTab = this.followMasterRepository.getCurrentNewTabMode();
+    const background = this.followMasterRepository.getCurrentBackgroundMode();
     this.broadcastToSlaves((client) => {
       client.activateIfExists(tag, newTab, background);
       client.clearHints();
@@ -125,8 +125,8 @@ export default class FollowMasterUseCase {
 
     this.followKeyRepository.pushKey(key);
 
-    let tag = this.getCurrentTag();
-    let matched = this.followMasterRepository.getTagsByPrefix(tag);
+    const tag = this.getCurrentTag();
+    const matched = this.followMasterRepository.getTagsByPrefix(tag);
     if (matched.length === 0) {
       this.cancelFollow();
     } else if (matched.length === 1) {
@@ -137,9 +137,9 @@ export default class FollowMasterUseCase {
   }
 
   private broadcastToSlaves(handler: (client: FollowSlaveClient) => void) {
-    let allFrames = [window.self].concat(Array.from(window.frames as any));
-    let clients = allFrames.map(w => this.followSlaveClientFactory.create(w));
-    for (let client of clients) {
+    const allFrames = [window.self].concat(Array.from(window.frames as any));
+    const clients = allFrames.map(w => this.followSlaveClientFactory.create(w));
+    for (const client of clients) {
       handler(client);
     }
   }
diff --git a/src/content/usecases/FollowSlaveUseCase.ts b/src/content/usecases/FollowSlaveUseCase.ts
index d471adb..fb805b9 100644
--- a/src/content/usecases/FollowSlaveUseCase.ts
+++ b/src/content/usecases/FollowSlaveUseCase.ts
@@ -34,7 +34,7 @@ export default class FollowSlaveUseCase {
   }
 
   countTargets(viewSize: Size, framePosition: Point): void {
-    let count = this.presenter.getTargetCount(viewSize, framePosition);
+    const count = this.presenter.getTargetCount(viewSize, framePosition);
     this.followMasterClient.responseHintCount(count);
   }
 
@@ -56,13 +56,13 @@ export default class FollowSlaveUseCase {
   }
 
   async activate(tag: string, newTab: boolean, background: boolean) {
-    let hint = this.presenter.getHint(tag);
+    const hint = this.presenter.getHint(tag);
     if (!hint) {
       return;
     }
 
     if (hint instanceof LinkHint) {
-      let url = hint.getLink();
+      const url = hint.getLink();
       let openNewTab = newTab;
       // Open link by background script in order to prevent a popup block
       if (hint.getLinkTarget() === '_blank') {
diff --git a/src/content/usecases/HintKeyProducer.ts b/src/content/usecases/HintKeyProducer.ts
index 241cd56..68f3fbd 100644
--- a/src/content/usecases/HintKeyProducer.ts
+++ b/src/content/usecases/HintKeyProducer.ts
@@ -19,14 +19,14 @@ export default class HintKeyProducer {
   }
 
   private increment(): void {
-    let max = this.charset.length - 1;
+    const max = this.charset.length - 1;
     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;
+    const len = this.charset.length;
     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;
diff --git a/src/content/usecases/KeymapUseCase.ts b/src/content/usecases/KeymapUseCase.ts
index a2e7cc3..074de72 100644
--- a/src/content/usecases/KeymapUseCase.ts
+++ b/src/content/usecases/KeymapUseCase.ts
@@ -37,17 +37,17 @@ export default class KeymapUseCase {
 
   // eslint-disable-next-line max-statements
   nextOps(key: Key): { repeat: number, op: operations.Operation } | null {
-    let sequence = this.repository.enqueueKey(key);
-    let baseSequence = sequence.trimNumericPrefix();
+    const sequence = this.repository.enqueueKey(key);
+    const baseSequence = sequence.trimNumericPrefix();
     if (baseSequence.length() === 1 && this.blacklistKey(key)) {
       // ignore if the input starts with black list keys
       this.repository.clear();
       return null;
     }
 
-    let keymaps = this.keymapEntityMap();
-    let matched = keymaps.filter(([seq]) => seq.startsWith(sequence));
-    let baseMatched = keymaps.filter(([seq]) => seq.startsWith(baseSequence));
+    const keymaps = this.keymapEntityMap();
+    const matched = keymaps.filter(([seq]) => seq.startsWith(sequence));
+    const baseMatched = keymaps.filter(([seq]) => seq.startsWith(baseSequence));
 
     if (matched.length === 1 &&
         sequence.length() === matched[0][0].length()) {
@@ -71,7 +71,7 @@ export default class KeymapUseCase {
   }
 
   private keymapEntityMap(): [KeySequence, operations.Operation][] {
-    let keymaps = this.settingRepository.get().keymaps.combine(reservedKeymaps);
+    const keymaps = this.settingRepository.get().keymaps.combine(reservedKeymaps);
     let entries = keymaps.entries().map(
       ([keys, op]) => [KeySequence.fromMapKeys(keys), op]
     ) as [KeySequence, operations.Operation][];
@@ -86,8 +86,8 @@ export default class KeymapUseCase {
   }
 
   private blacklistKey(key: Key): boolean {
-    let url = this.addressRepository.getCurrentURL();
-    let blacklist = this.settingRepository.get().blacklist;
+    const url = this.addressRepository.getCurrentURL();
+    const blacklist = this.settingRepository.get().blacklist;
     return blacklist.includeKey(url, key);
   }
 }
diff --git a/src/content/usecases/MarkUseCase.ts b/src/content/usecases/MarkUseCase.ts
index a7d5ad8..8cd0c72 100644
--- a/src/content/usecases/MarkUseCase.ts
+++ b/src/content/usecases/MarkUseCase.ts
@@ -17,7 +17,7 @@ export default class MarkUseCase {
   }
 
   async set(key: string): Promise<void> {
-    let pos = this.scrollPresenter.getScroll();
+    const pos = this.scrollPresenter.getScroll();
     if (this.globalKey(key)) {
       this.client.setGloablMark(key, pos);
       await this.consoleClient.info(`Set global mark to '${key}'`);
@@ -31,7 +31,7 @@ export default class MarkUseCase {
     if (this.globalKey(key)) {
       await this.client.jumpGlobalMark(key);
     } else {
-      let pos = this.repository.get(key);
+      const pos = this.repository.get(key);
       if (!pos) {
         throw new Error('Mark is not set');
       }
@@ -40,7 +40,7 @@ export default class MarkUseCase {
   }
 
   scroll(x: number, y: number): void {
-    let smooth = this.settingRepository.get().properties.smoothscroll;
+    const smooth = this.settingRepository.get().properties.smoothscroll;
     this.scrollPresenter.scrollTo(x, y, smooth);
   }
 
diff --git a/src/content/usecases/ScrollUseCase.ts b/src/content/usecases/ScrollUseCase.ts
index 32cbef1..c68c889 100644
--- a/src/content/usecases/ScrollUseCase.ts
+++ b/src/content/usecases/ScrollUseCase.ts
@@ -11,42 +11,42 @@ export default class ScrollUseCase {
   }
 
   scrollVertically(count: number): void {
-    let smooth = this.getSmoothScroll();
+    const smooth = this.getSmoothScroll();
     this.presenter.scrollVertically(count, smooth);
   }
 
   scrollHorizonally(count: number): void {
-    let smooth = this.getSmoothScroll();
+    const smooth = this.getSmoothScroll();
     this.presenter.scrollHorizonally(count, smooth);
   }
 
   scrollPages(count: number): void {
-    let smooth = this.getSmoothScroll();
+    const smooth = this.getSmoothScroll();
     this.presenter.scrollPages(count, smooth);
   }
 
   scrollToTop(): void {
-    let smooth = this.getSmoothScroll();
+    const smooth = this.getSmoothScroll();
     this.presenter.scrollToTop(smooth);
   }
 
   scrollToBottom(): void {
-    let smooth = this.getSmoothScroll();
+    const smooth = this.getSmoothScroll();
     this.presenter.scrollToBottom(smooth);
   }
 
   scrollToHome(): void {
-    let smooth = this.getSmoothScroll();
+    const smooth = this.getSmoothScroll();
     this.presenter.scrollToHome(smooth);
   }
 
   scrollToEnd(): void {
-    let smooth = this.getSmoothScroll();
+    const smooth = this.getSmoothScroll();
     this.presenter.scrollToEnd(smooth);
   }
 
   private getSmoothScroll(): boolean {
-    let settings = this.settingRepository.get();
+    const settings = this.settingRepository.get();
     return settings.properties.smoothscroll;
   }
 }
diff --git a/src/content/usecases/SettingUseCase.ts b/src/content/usecases/SettingUseCase.ts
index 4608039..67d1be6 100644
--- a/src/content/usecases/SettingUseCase.ts
+++ b/src/content/usecases/SettingUseCase.ts
@@ -12,7 +12,7 @@ export default class SettingUseCase {
   }
 
   async reload(): Promise<Settings> {
-    let settings = await this.client.load();
+    const settings = await this.client.load();
     this.repository.set(settings);
     return settings;
   }