Skip to main content

🚀 In our NEW AI Bootcamp you'll build a working app in 28 days, no experience required. Free to all subscription levels.

✨ Earn college credits in Cybersecurity, JS, HTML, CSS and Python

Join the Treehouse affiliate program and earn 25% recurring commission! 🤑

  • Treehouse Logo
    • For Individuals
    • For Businesses
    • For Schools
    • For Libraries
    • For Military
    • All Courses
    • Tracks
    • AI Bootcamp
    • College Credit
    • Techdegree Bootcamps
    • Front End Development
    • Full Stack JavaScript
    • Code Adventures
    • Discord
    • Forum
    • Success Stories
    • Treehouse Links
    • 100 Days of Code
    • Explore
    • Career Toolbox
    • Free Treehouse Near Me
    • Affiliates
    • Blog
    • Support
    • About
    • Learn
    • Beginner's Guide to Coding
    • Data Analysis with SQL & Python
    • Front-End Web Development
    • Python Programming Basics
    • Techdegree Bootcamp Overview
    • UX Design Fundamentals
    • AI Tools for Beginners
  • For Individuals For Businesses For Schools For Libraries For Military
  • All Courses Tracks AI Bootcamp College Credit
  • Techdegree Bootcamps Front End Web Development Full Stack JavaScript
  • Code Adventures Discord Forum Success Stories Treehouse Links 100 Days of Code
  • Explore Career Toolbox Free Treehouse Near Me Affiliates Blog Support About
    Learn Beginner's Guide to Coding Data Analysis with SQL & Python Front-End Web Development Python Programming Basics Techdegree Bootcamp Overview UX Design Fundamentals AI Tools for Beginners
  • Sign In
  • Free Trial
Instagram Twitter Facebook YouTube LinkedIn
Loading banner... Start your free trial at Treehouse
    • Newest
      • Newest
      • Active
      • Unanswered
      • Featured
    • All Topics
      • All Topics
      • • General Discussion
      • • AI
      • • APIs
      • • Coding for Kids
      • • College Credit
      • • Computer Science
      • • CSS
      • • Data Analysis
      • • Databases
      • • Design
      • • Development Tools
      • • Digital Literacy
      • • Game Development
      • • Go Language
      • • HTML
      • • Java
      • • JavaScript
      • • Learning Resources
      • • Machine Learning
      • • No-Code
      • • PHP
      • • Professional Growth
      • • Python
      • • Quality Assurance
      • • React
      • • Ruby
      • • Security
      • • Swift
      • • Vibe Coding
  • kingsley Emeka
    seal-mask
    .a{fill-rule:evenodd;}techdegree seal-36
    kingsley Emeka
    Full Stack JavaScript Techdegree Graduate 18,238 Points

    Failed npm test result

    Posted December 11, 2019 1:32pm by kingsley Emeka
    .a{fill-rule:evenodd;}techdegree seal-36
    kingsley Emeka
    Full Stack JavaScript Techdegree Graduate 18,238 Points
    • JavaScript
    • JavaScript Unit Testing
    • Behavior Driven Development with Mocha & Chai
    • Writing Our First Test Suite - Part 2

    1 Answer

  • gerardo keys
    gerardo keys
    14,292 Points

    I still don't understand how this works...

    Posted May 30, 2019 11:46pm by gerardo keys
    gerardo keys
    14,292 Points
    • JavaScript
    • JavaScript Unit Testing
    • Behavior Driven Development with Mocha & Chai
    • Writing Our First Test Suite - Part 2

    1 Answer

  • Jay Azares
    Jay Azares
    16,600 Points

    Getting this error in Mocha testing: TypeError: Cannot read property 'filter' of undefined

    Posted May 4, 2017 7:22pm by Jay Azares
    Jay Azares
    16,600 Points
    • JavaScript
    • JavaScript Unit Testing
    • Behavior Driven Development with Mocha & Chai
    • Writing Our First Test Suite - Part 2

    2 Answers

  • Rick Klaras
    Rick Klaras
    20,183 Points

    TypeError: Cannot read property 'locations' of undefined

    Posted October 25, 2016 5:30am by Rick Klaras
    Rick Klaras
    20,183 Points
    • JavaScript
    • JavaScript Unit Testing
    • Behavior Driven Development with Mocha & Chai
    • Writing Our First Test Suite - Part 2

    1 Answer

Posting to the forum is only allowed for members with active accounts.
Please sign in or sign up to post.

Techdegree

  • Front End Web Development
  • Full Stack JavaScript
SEE ALL

Tracks

  • Learn to Code for Beginners
  • Beginning Python
  • Beginning SQL
  • Beginning Java
SEE ALL

Courses

  • JavaScript Basics
  • Intro to HTML & CSS
  • Python Basics
  • CSS Layout
SEE ALL

About Us

  • About
  • Blog
  • Community
  • Stories
  • Contact
  • Gift Card

Explore

  • Plans
  • Affiliates
  • Perks
  • Shop
  • Free Treehouse Near Me
  • Treehouse for Libraries
  • Treehouse for Businesses

Treehouse is an online technology education platform founded in 2011. Treehouse offers more than 700 self-paced, video-based courses in web development, programming, data analysis, design, and AI, plus two project-based bootcamp programs in Front End Web Development and Full Stack JavaScript. Individual Treehouse plans start at $25 per month and include a 7-day free trial. Treehouse serves individual learners, businesses, schools, and public libraries. Cardholders at participating U.S. public libraries can use Treehouse for free. Select Treehouse courses, offered with University Pathways International, are recommended for college credit by ACE and NCCRS. Treehouse learners earn digital certificates for completed Tracks.

Terms & Conditions · Privacy · © 2026 Treehouse Island, Inc.
  • Twitter
  • YouTube
  • Facebook
  • LinkedIn
  • Instagram
  • Discord