In Jest run one specific test in a file using npm test

02/08/19  Public, Testing / TDD


  • using Jest JavaScript framework
  • have an npm script in package.json for test set to jest
  "scripts": {
    "test": "jest"
  • have a test file in the following location:

1 vote - harrylevine

Open and edit Rails 5.2 credentials file

10/12/18  Public, Rails General

Here is an example of how to open and edit the new credentials file that came out in Rails 5.2. This example is using Sublime as the editor.

1. From the root of the project run:

➜  EDITOR="subl --wait" rails credentials:edit


1 vote - harrylevine

How to add a new path to my PATH

06/20/18  Public, Command Line

Here was my use case.

My starting PATH

➜  echo $PATH

1 vote - harrylevine

Explanation of the Singleton Pattern in ruby

06/18/18  Public, Ruby General

1 vote - harrylevine

How to look at an older version of the rails API docs

05/07/18  Public, Rails General

You add in /v4.2.1/ into the URL, for the version in question. For example:

Before URL:

After URL:

1 vote - harrylevine

To run sidekiq

07/25/18  Public, Rails General

For perform_later

And in a separate tab:

bundle exec sidekiq

To view the local dev page of queues and jobs running, failed, etc., visit:


1 vote - harrylevine

Difference between include vs extend

03/05/18  Public, Ruby General

Great article by that explains the difference between using include vs extend andself, when using modules:

1 vote - harrylevine

Require and load a gem in IRB for testing purposes while developing the gem

01/20/18  Public, Ruby General, Gems

  • cd into the root of the gem
  • run bin/console



  • cd into the root of the gem
  • run bundle console


  • cd into the root of the gem
  • run irb -I lib
  • run require "name_of_gem"

For example:

$ i...

1 vote - harrylevine

Workflow for upgrading Rails versions

12/25/17  Public, Rails General

First, read through the Rails "A Guide for Upgrading Ruby on Rails".

In general, you can follow the steps in this [Ruby on Rails Upgrade Guide blog post](

1 vote - harrylevine