Monday, March 23, 2020

The TDD Course for Beginners : Learn by Practicing 7 Katas

Learn how to do Test Driven Development using Ruby within 4 hours. You will get:

1. The transcript of the entire course in PDF.
2. TDD in Ruby ebook in PDF, Mobi and Epub formats
3. Members only TDD tutorial website that walks you through every exercise in the course.
4. Monthly Google hangout Q&A session that supports your learning objectives.
5. All the slides used in the course in PDF format.
6. TDD Course Tools Checklist for every sub-skill covered in the course.
7. TDD in Ruby Course Outline that was used to create the course.

How do I get access to the videos and all the above goodies?

For only $9 / month, you get my support and access to all of the above. Send me payment via Paypal to to get access today!


Jeff Casimir, Principal, Jumpstart Lab


The actual coding TDD examples for Fizz Buzz and Fibonacci were really well done
During the coding exercises the refactoring of code was a good illustration of how to improve certainty of test results
Good overview of the importance of testing
Each lecture / exercise was only 5-10 minutes providing nice incremental gains in the course


The instructor's delivery was not engaging - students tune out very quickly
First 61 minutes were very high level and included no actual coding
Instructors speaking voice was monotone and slow for the entire course no inflection, jokes, or anything to keep your attention
The audio between segments varied in quality to sometimes low quality not ideal for a $200 course
Instructor used whiteboard to write notes and diagram concepts during lecture (also wrote in cursive and at least 1 time wrote off viewable screen)


We wouldn't recommend it for Turing pre-requisite work, but could be valuable supporting material for students in the class.

Mylene Reiners

When you want a theoretical background on TDD, this course is great (and the Ruby part is not too hard for people knowing only a little Ruby...)

Yury Voloshin

This is a good introduction to TDD for those who either have never used it or who have a very rudimentary understanding of it. Some of the more advanced concepts toward the end are somewhat rushed through, but I' sure that can't be helped due to time constraints and to the nature of the material. At least now I know the topics that I need to into more deeply.


This course introduces a solid foundation for practicing TDD. The instructor definitely knows what he's teaching. Information is divided in small logical and understandable chunks/lectures.

Jesse Mignac

Techniques, examples and theoretical material. This course is a really nice start to TDD with Ruby

Andrew Platkin

Very good pace and learned alot

Thom Parkin

The beginning of this course seems a bit slow and very dry. But your patience is well rewarded because the depth and detail of information provided is priceless! Mr. Paranj uses a time-tested technique of methodical presentation of ideas, one built upon the other, to its ultimate success. I am grateful and impressed by this course.

Jikku Jose

I am very happy to have such a comprehensive course from Mr. Paranj. I have been trying to do TDD in my projects for quite sometime without much success. This course helped a lot to expose much of the concepts and details one should focus on while doing TDD.  I wish the examples mentioned in "Fake It till you make it" and "Triangulation" was a bit more involved rather than the basic ones presented so that the techniques could be better understood.  I thank Mr. Paranj and Udemy for the course, it really helped me. Hope more advanced Ruby related materials can be brought out.

Pawel Jackowski

Instructor knows TDD and explains it with ease. I am quite familiar with technique and just wanted to refresh knowledge and I still recommend course. I definitely learned something about common mistakes and importance of every step in TDD sequence. I enrolled for free.

Steve Freeman

Instructor uses katas very effectively to show the patterns behind TDD. His clear examples and pointers to material for further study were very helpful and I look forward to practicing katas on my own. If you're trying to make sense of TDD I highly recommend this class!

What are the requirements?

Basic programming skills
You need to have your favorite text editor installed on your machine
You need Ruby 2.0 or above installed on your machine.

What am I going to get from this course?

Do Problem Domain Analysis
Do Solution Domain Analysis
Design Test Cases
Write Tests First
Apply Canonical Test Structure when having difficulty in writing a test first.

Who is the target audience?

Beginners to Test Driven Development
You should already know how to write programs in Ruby
You should already know how to create an instance of a class and invoke methods.

Course Description

In this course you will learn the basics of Test Driven Development. You will learn how to do Problem Domain Analysis, Solution Domain Analysis, Designing Test Cases and Writing Tests First. Learn the Basics of Test Driven Development in Ruby using this Beginner Course. This course will take 4 hours to complete.

Practice skills using 7 katas

  • Use the downloadable checklists to guide you when coding
  • Learn 3 different techniques to do Test Driven Development
  • You can be more productive if you practice TDD at work. Companies that adopt Test Driven Development are great places to work.
The material used in this course is the result of feedback from students who attended my TDD bootcamps and tutorials. This is a course designed by a developer for developers.

The concepts are first explained in a presentation. Then a coding demo illustrates how to apply the theory in practice. At the end of the lesson an exercise is given to reinforce the material.

You will learn the following concepts:
  • Assertions
  • The structure of a test
  • TDD Cycle
  • Minimal Implementation
  • Starter Test
  • Story Test
  • Next Test
  • Refactoring
  • Obvious Implementation
  • Fake It Till You Make It
  • Triangulation
  • Hiding Implementation Details
You will be able to attend interviews for companies that demand TDD skills to get a six-figure salary. Complete with working files and code samples, you'll be able to work alongside the instructor and will receive a verifiable certificate of completion upon finishing the course. I have interviewed people and I have seen the common mistakes made by candidates.

Subscribe Now

For only $9 / month, you get my support and access to all of the above. Send me payment via Paypal to to get access today!

Monday, January 16, 2017

Credit card declined : This customer has no attached payment source.

I was getting this error when using Stripe to subscribe a customer. Solution:

def allowed_params
  params.permit(:plan_name, :email, :password, :stripeToken, :authenticity_token)

customer = Stripe::Customer.create(email: email, plan: plan_id, source: stripe_token)  

<%= stylesheet_link_tag    'application', media: 'all', 'data-turbolinks-track' => false %>
<%= javascript_include_tag 'application', 'data-turbolinks-track' => false %>

Sunday, January 15, 2017

Rails Screencasts

Checkout the Rails screencast Autocomplete in Rails 5 :
It covers using typeahead.js.

Checkout the Rails screencast Auto Complete Association in Rails 5 :
It covers using jQuery for autocomplete feature.

Checkout the Rails screencast Movie Review Rails 5 App :
It covers using Twitter Bootstrap 4

Checkout the Rails screencast Movie Review Rails 5 App :
It covers using Elasticsearch for full text search

Checkout the Rails screencast Movie Review Rails 5 App - Part 3 :
This covers devise.

Saturday, January 14, 2017

Simple Search Form in Rails 5

Learn how to use a simple search form to search the database for records that has the given string in one of the columns of a table. Watch the Rails screencast Episode #30

Thursday, December 29, 2016

Concept Diagram

A Concept Diagram is a graphic organizer that clarifies central concepts in a reading selection and in relating similar or associated information to this key idea. The steps to build a Concept Diagram:

Convey the central idea.
Offer the overall concept.
Note any key words.
Classify characteristics.
Explore examples and non-examples.
Practice with new examples.
Tie down the definition.

This sequence of steps provides a process for organizing and interpreting the content of a reading selection.

Steps to a Concept Diagram:

  1. Select a reading text for discussion.
  2. Have students identify the overall theme of the document and the major subthemes or concepts that together make up the document.
  3. Ask students to write down all key words in the selection and then group these terms in logical categories.
  4. Encourage students to suggest examples and non-examples of the key terms and concepts identified.
  5. Have the students produce a final, formal definition of key words and concepts by combining the things they learned when categorizing the words and providing examples.


1. Reading Educator
2. Lenski, Susan D., Wham, Mary Ann, & Johns, Jerry L. (1999). Reading and learning strategies for middle and high school students. Dubuque, IA: Kendall/Hunt.

RubyPlus Podcast Episode 21

require dlopen rvm ruby rails

/Users/bparanj/.rvm/rubies/ruby-2.3.1/lib/ruby/2.3.0/irb/completion.rb:10:in `require': dlopen(/Users/bparanj/.rvm/rubies/ruby-2.3.1/lib/ruby/2.3.0/x86_64-darwin13/readline.bundle, 9): Library not loaded: /usr/local/opt/readline/lib/libreadline.6.dylib (LoadError)


group :development, :test do
  gem 'rb-readline'

and install the gem. Now the rails console will work.

GraphQL Basics in Rails 5

Checkout the GraphQL Basics in Rails 5 screencast

This screencast covers the basics of GraphQL. Demonstrates a simple hello GraphQL program using graphql gem and exposing a person has many friends nested ActiveRecord relationship as an API using graphql. The Rails engine graphiql-rails is used to play with the backend API.