Computer Setup

Before we can do much programming, we need to make sure our machines are properly configured with a functional Development environment. Let’s walk through this process now to make sure we have what we need.

Here are the basics we’re going to go over:

  • A text editor. Developers need to work with text in a different way than your average MS Word user. We’ll want a text editor designed for software development.
  • A system Terminal for interacting with our machine from the command line. Fortunately macOS already ships with one.
  • macOS “Command Line Tools” – these are some system dependencies needed for some of the tools we will use.
  • Homebrew: This is a “package manager” for installing other developer-related programs. You can think of it as the “App Store for nerds.”
  • Git (An application for handling “version control” of our software projects)
  • The Ruby programming language – version 2.2 in particular

Xcode & Command Line Tools

Xcode is a huge suite of development tools published by Apple. If we wanted to develop software for the Apple Ecosystem (iPhone apps, macOS apps, etc), we would use Xcode as our editor. But even if we aren’t working in this ecosystem, Xcode provides some system dependencies that we’ll want to have available.

You’ll want to install it before attempting to install anything else.

Download and install from the Apple App Store - this will probably take a little while.

Open terminal and run xcode-select --install, enter your user password

Now you should have the underlying tools we need to move forward.


Homebrew is a package management system that makes it easy to install hundreds of open source projects and compile them from source for maximum performance on your machine.

Open the Terminal then run the homebrew installation script:

ruby -e "$(curl -fsSL"

It will ask you for your password. This is the password to log in to your account on the computer. It needs this because it installs its packages in a place that all users of this computer can access.

Verifying Homebrew

When it has completed the installation run brew doctor and it should tell you that everything is fine:

brew doctor
Your system is ready to brew.

Modifying your PATH

If you got a warning from Homebrew about your path, do the following:

echo 'export PATH="/usr/local/bin:$PATH"' >> ~/.bash_profile
source ~/.bash_profile

Now run brew doctor again and the warning should be gone.

Aside: PATH

Your PATH is a system configuration property which tells your computer which places to look for underlying programs when you want to run a command.

For example, when we type ruby at the command line to run a ruby program, our PATH will help the system know where on the system to find ruby. By adding this directory to our PATH, we’re telling the system how to find the various applications we will install using Homebrew

Aside: ~/.bash_profile

When we use our terminal, we’re actually using a program called a “Shell” to interact with the underlying Operating System. Specifically, we’re using a shell called Bash.

The file ~/.bash_profile contains settings and commands to help us configure the shell, so when we have a bit of configuration code such as setting our PATH, it often goes in our ~/.bash_profile.


Git is the version control system of choice in the Ruby community. Xcode installed an older version of Git for you, but let’s update it.

brew install git
==> Downloading
########################################################### 100.0%

Configuring Git

If you haven’t used git before (don’t worry, we’ll be covering its usage in future classes), we’ll want to configure it with some basic information about us.

We can tell git to configure itself using the git config command from our terminal.

Additionally, we’re setting “global” configurations for git, so we’ll use the --global flag when we provide it with a new piece of configuration.

Tell git your name and email address by using the following commands, substituting your own name and email:

git config --global "John Doe"
git config --global

Install Google Chrome Canary

Chrome Canary

Google Chrome Canary is a bleeding edge, experimental version of Chrome, with the latest features. This web browser is great for general internet perusing, but web developers like it because it has very useful developer tools (the console), which you will use in the prework and extensively during class.

Install the Sublime command line tools

  • Make sure you download Sublime
  • Open your finder (Command-Space for spotlight, type Finder, and hit enter)
  • Move Sublime from your downloads to your Applications folder.
  • Open your terminal (Command-Space for spotlight, type Sublime, and hit enter).
  • First up, check your own $PATH by typing the following in your terminal line: echo $PATH This is what mine returns: /usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin

    As you can see the /usr/local/bin path is included by default on OS X.

  • Now, copy and paste the following line to put in your terminal: ln -s "/Applications/Sublime" /usr/local/bin/sublime
  • Open a new terminal window (Command-T) and type sublime .
  • Experiment with creating a file in Sublime and using ls in the terminal to see it. Try creating a file in the terminal with touch and see if it shows up in Sublime.

(Full instructions can be found here)

Install Node.js using nvm

  • touch ~/.bash_profile
  • curl -o- | bash
  • Close and reopen the Terminal window
  • nvm ls-remote
  • Install the latest, most-stable version in the list.
    • As of cohort 1706 the latest stable version was 8.1.2. Run the command nvm install 8.1.2 (or whatever version shows up as the latest version on that list at this time).

Setup Exercisms

We introduce exercisms later in the module. For now, we’re just getting things setup.

  • Visit In the top right corner, click “Log in with Github” and follow the authentication steps.
  • In your terminal, install jasmine-node (a javascript testing suite): npm install jasmine-node -g
  • In your terminal, using brew, install the exercism CLI: brew install exercism
  • Verify that it was installed properly by running: exercism --version (If there was a problem you will get an error message saying command not found.)
  • Go back to your exercism account online, under your profile, in “API Key”, you will find a configuration command that you need to type into your terminal. Copy that command and paste it into your terminal.
  • In your terminal, navigate to the exercism directory: cd exercism
  • Now type exercism fetch javascript
  • Now type cd javascript
  • Now type cd hello-world
  • Now type jasmine-node .
  • Success looks like this in your terminal:


  1) Hello World says hello world with no name
     Expected undefined to equal 'Hello, World!'.
     Error: Expected undefined to equal 'Hello, World!'.
    at .<anonymous> (/Users/breethomas/exercism/javascript/hello-world/hello-world.spec.js:7:34)

Finished in 0.01 seconds
1 test, 1 assertion, 1 failure, 0 skipped
  • If you get anything else, let an instructor know and we’ll come trouble-shoot.
  • If you are successful, cd back to your root directory: cd ~

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