Add :help command to open help

src/background/controllers/CommandController.ts

@@ -96,6 +96,9 @@ export default class CommandController {
       return this.commandIndicator.quitAll();
     case 'set':
       return this.commandIndicator.set(keywords);
+    case 'h':
+    case 'help':
+      return this.commandIndicator.help();
     }
     throw new Error(words[0] + ' command is not defined');
   }

src/background/domains/CommandDocs.ts

@@ -8,4 +8,5 @@ export default {
   bdeletes: 'Close all tabs matched by keywords',
   quit: 'Close the current tab',
   quitall: 'Close all tabs',
+  help: 'Open Vim Vixen help in new tab',
 } as {[key: string]: string};

src/background/presenters/HelpPresenter.ts

@@ -0,0 +1,10 @@
+import { injectable } from 'tsyringe';
+
+const url = 'https://ueokande.github.io/vim-vixen/';
+
+@injectable()
+export default class HelpPresenter {
+  async open(): Promise<void> {
+    await browser.tabs.create({ url, active: true });
+  }
+}

src/background/usecases/CommandUseCase.ts

@@ -4,6 +4,7 @@ import * as parsers from './parsers';
 import * as urls from '../../shared/urls';
 import TabPresenter from '../presenters/TabPresenter';
 import WindowPresenter from '../presenters/WindowPresenter';
+import HelpPresenter from '../presenters/HelpPresenter';
 import SettingRepository from '../repositories/SettingRepository';
 import BookmarkRepository from '../repositories/BookmarkRepository';
 import ConsoleClient from '../infrastructures/ConsoleClient';
@@ -15,6 +16,7 @@ export default class CommandIndicator {
   constructor(
     private tabPresenter: TabPresenter,
     private windowPresenter: WindowPresenter,
+    private helpPresenter: HelpPresenter,
     private settingRepository: SettingRepository,
     private bookmarkRepository: BookmarkRepository,
     private consoleClient: ConsoleClient,
@@ -136,7 +138,11 @@ export default class CommandIndicator {
     return this.contentMessageClient.broadcastSettingsChanged();
   }
 
-  async urlOrSearch(keywords: string): Promise<any> {
+  help(): Promise<void> {
+    return this.helpPresenter.open();
+  }
+
+  private async urlOrSearch(keywords: string): Promise<any> {
     let settings = await this.settingRepository.get();
     return urls.searchUrl(keywords, settings.search);
   }