Make find as a clean architecture

src/content/presenters/FindPresenter.ts

@@ -0,0 +1,59 @@
+import ConsoleClient, { ConsoleClientImpl } from '../client/ConsoleClient';
+
+export default interface FindPresenter {
+  find(keyword: string, backwards: boolean): boolean;
+
+  clearSelection(): void;
+
+  // eslint-disable-next-line semi
+}
+
+// window.find(aString, aCaseSensitive, aBackwards, aWrapAround,
+//             aWholeWord, aSearchInFrames);
+//
+// NOTE: window.find is not standard API
+// https://developer.mozilla.org/en-US/docs/Web/API/Window/find
+interface MyWindow extends Window {
+  find(
+    aString: string,
+    aCaseSensitive?: boolean,
+    aBackwards?: boolean,
+    aWrapAround?: boolean,
+    aWholeWord?: boolean,
+    aSearchInFrames?: boolean,
+    aShowDialog?: boolean): boolean;
+}
+
+// eslint-disable-next-line no-var, vars-on-top, init-declarations
+declare var window: MyWindow;
+
+export class FindPresenterImpl implements FindPresenter {
+  private consoleClient: ConsoleClient;
+
+  constructor({ consoleClient = new ConsoleClientImpl() } = {}) {
+    this.consoleClient = consoleClient;
+  }
+
+  find(keyword: string, backwards: boolean): boolean {
+    let caseSensitive = false;
+    let 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);
+    if (found) {
+      return found;
+    }
+    this.clearSelection();
+
+    return window.find(keyword, caseSensitive, backwards, wrapScan);
+  }
+
+  clearSelection(): void {
+    let sel = window.getSelection();
+    if (sel) {
+      sel.removeAllRanges();
+    }
+  }
+}