03-understand-the-hazards-of-using-imperative-code.js

/*
Understand the Hazards of Using Imperative Code:
Examine the code in the editor.
It's using a method that has side effects in the program, causing incorrect behaviour.
The final list of open tabs, stored in finalTabs.tabs, should be
['FB', 'Gitter', 'Reddit', 'Twitter', 'Medium', 'new tab', 'Netflix', 'YouTube', 'Vine', 'GMail', 'Work mail', 'Docs',
'freeCodeCamp', 'new tab'] but the list produced by the code is slightly different.
Change Window.prototype.tabClose so that it removes the correct tab.

- finalTabs.tabs should be ['FB', 'Gitter', 'Reddit', 'Twitter', 'Medium', 'new tab', 'Netflix', 'YouTube', 'Vine',
'GMail', 'Work mail', 'Docs', 'freeCodeCamp', 'new tab']
 */
// tabs is an array of titles of each site open within the window
const Window = function (tabs) {
    this.tabs = tabs; // We keep a record of the array inside the object
};

// When you join two windows into one window
Window.prototype.join = function (otherWindow) {
    this.tabs = this.tabs.concat(otherWindow.tabs);
    return this;
};

// When you open a new tab at the end
Window.prototype.tabOpen = function (tab) {
    this.tabs.push('new tab'); // Let's open a new tab for now
    return this;
};

// When you close a tab
Window.prototype.tabClose = function (index) {

    // Only changed code below this line

    const tabsBeforeIndex = this.tabs.splice(0, index); // Get the tabs before the tab
    const tabsAfterIndex = this.tabs.splice(1); // Get the tabs after the tab

    this.tabs = tabsBeforeIndex.concat(tabsAfterIndex); // Join them together

    // Only changed code above this line

    return this;
};

// Let's create three browser windows
const workWindow = new Window(['GMail', 'Inbox', 'Work mail', 'Docs', 'freeCodeCamp']); // Your mailbox, drive, and other work sites
const socialWindow = new Window(['FB', 'Gitter', 'Reddit', 'Twitter', 'Medium']); // Social sites
const videoWindow = new Window(['Netflix', 'YouTube', 'Vimeo', 'Vine']); // Entertainment sites

// Now perform the tab opening, closing, and other operations
const finalTabs = socialWindow
    .tabOpen() // Open a new tab for cat memes
    .join(videoWindow.tabClose(2)) // Close third tab in video window, and join
    .join(workWindow.tabClose(1).tabOpen());
console.log(finalTabs.tabs);