Device Finger Printing

Errata for Articles on www.rubyplus.com

DK Smith has offered me his time to point out some errors, spelling mistakes etc. This page will document his findings.

Linode Box Images

git prompts for passphrase after mac os upgrade

Solution

1. Create (or edit if it exists) the following ~/.ssh/config file:
   

   Host *
     UseKeychain yes
     AddKeysToAgent yes
     IdentityFile ~/.ssh/id_rsa

2. eval "$(ssh-agent -s)" 

3. ssh-add -K ~/.ssh/id_rsa

Installing Rugged on Mac OS

Check if Mac is 64 bit: 

getconf LONG_BIT

ERROR: CMake is required to build Rugged

cat /Users/bparanj/.rvm/gems/ruby-2.3.1@headache/extensions/x86_64-darwin-17/2.3.0/rugged-0.25.1.1/gem_make.out

ERROR: CMake is required to build Rugged.

brew install cmake

Must be superuser to create this extension.

ALTER ROLE SUPERUSER;

createuser --superuser postgres2

gpg: keyserver receive failed: No route to host

Solution:

gpg-connect-agent --dirmngr 'keyserver --hosttable'

BYE

gpg --keyserver hkp://b4ckbone.de --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3 7D2BAF1CF37B13E2069D6956105BD0E739499BDB

When to Apply Memoization

Apply memoization, when two conditions are met:

1. Optimal sub structure
2. Overlapping sub problems

Make sure that `gem install libv8 -v '3.16.14.19' --source 'https://rubygems.org/'` succeeds before bundling.

This happened on Mac OS 10.10.5. I needed a specific version of libv8, so I used the -v flag in gem install.

Resolution

gem install libv8 -v 3.16.14.19 -- --with-system-v8

bundle config build.libv8 --with-system-v8

SSL Notes

git clone https://github.com/letsencrypt/letsencrypt
cd letsencrypt
./letsencrypt-auto --apache --rsa-key-size 4096


./letsencrypt-auto --apache -d example.com -d www.example.com -d foo.example.com -d bar.example.com -d baz.example.com


SSL with Let's Encrypt in Apache

Skill vs Challenge

When you work on improving your coding skill, be aware that you will experience these feelings that depends on your current skill level and the challenge level of the problem. Our goal is to be able to take on high challenges at a high skill level so that we can experience the Flow.

Quick Sort Algorithm Visualization

SPK and DKIM Configuration

Installing Graphicsmagick on Mac

cd /usr/local/src
curl --remote-name --location ftp://ftp.graphicsmagick.org/pub/GraphicsMagick/1.3/GraphicsMagick-1.3.27a.tar.gz

tar -xzvf GraphicsMagick-1.3.27a.tar.gz
cd GraphicsMagick-1.3.27a

./configure CC=clang \
  LDFLAGS="-L/usr/local/libjpeg/lib -L/usr/local/libpng/lib -L/usr/local/libtiff/lib" \
  CPPFLAGS="-I/usr/local/libjpeg/include -I/usr/local/libpng/include -I/usr/local/libtiff/include" \
  --prefix=/usr/local/mac-dev-env/graphicsmagick-1.3.27a
make
sudo make install

sudo ln -s mac-dev-env/graphicsmagick-1.3.27a /usr/local/graphicsmagick


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

source ~/.bash_profile

gm version

Reference

Installing graphicsmagick on Mac

Installing phantomjs on Mac 10.10.5

Cliver::Dependency::NotFound: Could not find an executable ["phantomjs"] on your path.

brew install phantomjs

MiniMagick::Invalid: ImageMagick/GraphicsMagick is not installed

brew install graphicsmagick

Error: SHA256 mismatch
Expected: 2f1e960d92ce3b3abd03d06dfec9637dfbd22febf107a536b44f7a47c60659f6
Actual: 7a07d3f7cca5c0b38ca811984ef8da536da32932d68c1a6cce33ec2462b930bf
Archive: /Users/bparanj/Library/Caches/Homebrew/libpng-1.6.34.tar.xz


brew uninstall libpng
brew cleanup -s
brew install graphicsmagick

Selenium::WebDriver::Error::WebDriverError:

Selenium::WebDriver::Error::WebDriverError:
        Unable to find Mozilla geckodriver. Please download the server from https://github.com/mozilla/geckodriver/releases and place it somewhere on your PATH. More info at https://developer.mozilla.org/en-US/docs/Mozilla/QA/Marionette/WebDriver
       
Resolution

brew install chromedriver

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 bala.paranj@zepho.com to get access today!

Testimonials

Jeff Casimir, Principal, Jumpstart Lab

Pros:-

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

Cons:-

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)

Summary:

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.

Nikolas

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 bala.paranj@zepho.com to get access today!

User Story Mapping

ActionController::UnknownFormat (ActionController::UnknownFormat):

This happens with Devise when working with API only Rails app.
Solution: Add   respond_to :json in the controller.

ActiveModel::UnknownAttributeError (unknown attribute 'user' for User.):

Devise throws this error.

Solution:

Don't use the protected method signup_params. I used my own method:

  def allowed_params
    params.permit(:first_name, :email, :password, :password_confirmation)
  end 

the build_resource call uses this method.

    build_resource(allowed_params)

I copied the create action from Devise::Registrations controller and customized it:

  def create

    build_resource(allowed_params)

    

    resource.save

    if resource.persisted?

      if resource.active_for_authentication?

        sign_up(resource_name, resource)

        respond_with resource, location: after_sign_up_path_for(resource)

      else

        expire_data_after_sign_in!

        respond_with resource, location: after_inactive_sign_up_path_for(resource)

      end

    else

      clean_up_passwords resource

      set_minimum_password_length

      respond_with resource

    end

  end