Solution

src/pageObject.js

@@ -1,15 +1,38 @@
 'use strict';
 
 class Header {
-
-};
+  get logo() {
+    return 'Conduit logo';
+  }
+}
 
 class PageObject {
+  constructor(url) {
+    this.url = url;
+    this.header = new Header();
+  }
 
-};
+  clickOnLogo() {
+    return `Click on the ${this.header.logo}`;
+  }
+}
 
 class ArticlePage extends PageObject {
+  constructor(url, slug) {
+    super(url + slug);
+  }
+
+  get commentButton() {
+    return '[Publish comment] button';
+  }
+
+  clickOnCommentButton() {
+    return `Click on the ${this.commentButton}`;
+  }
 
+  assertPageOpened() {
+    return `The ${this.url} is opened`;
+  }
 };
 
 module.exports = {