Despite

This gem introduces new advanced verbose flow-control operators to Ruby language.

Description

Have you ever been shown a git blame output with your name and a question: "What will happen if this is nil?" or "Have you thought of the case when there are no orders for a customer?" or "What if they haven't entered their mobile phone?".

This gem is designed to stop these stupid questions forever. With despite and even_if operators introduced by it, is has finally became possible to explicitly and verbosely designate pieces of code you are aware to be faulty as well as to show you don't give a fuck.

Installation

Add this line to your application's Gemfile:

gem 'despite'

Or, if you would like just to install this gem globally, execute:

gem install despite

Usage

The purpose of the despite operator is to explicitly demonstrate, that you are aware of some problem or potential error, but you are conciously ignoring it and its possible negative consequences.

The despite operator accepts an expression and a block. If expression evaluates to true the block is executed and the result of the block is returned.

The typical usage would be:

# Divide by zero openly and proudly
y = 0

despite y == 0 do
  #ZeroDivisionError is raised
  puts x / y
end

If no block is passed, the operator will return the result of the expression:

  x = despite(5) # x == 5

Thus it is possible to chain despite calls:

  share = nil

  despite(users.count == 0) && despite(total_income.nil?) do
    # Dividing nil by zero!
    avg_income = total_income / users.count
  end

The despite operator is designed to be used only with true expressions. By using it, you are saying: "Yes, I know that the X is true, but despite that I am going to do Y." Thus, if the condition evaluates to false, it is considered to be an error in the code, and Despite::AssertionError exception is raised.

  user.name = 'Donald'

  # Despite::AssertionError
  despite user.name.nil? do
     puts user.name
  end

However, this behavior is not always desired. Sometimes you cannot be sure the problem is there, but you still would like to demonstrate, that you are aware of the possible negative outcome. For this, even_if operator is provided.

The usage of even_if operator is similar to that of the despite operator, except for it doesn't check the value of the condition, and thus the block passed is executed no matter what the condition is.

With even_if operator you are saying: "Yes, I am aware that there might be some problem, but I am going to execute this code whatsoever."

  # This even may occasionally work!
  sale_price = even_if product.nil? do
    product.price * 0.95
  end

Contributing

Feature requests and bug reports are welcome here at GitHub. However if you want to contribute, make sure your pull request passes all the tests, and the new features are 100% covered by tests too. Also make sure you have no warnings with the default Rubocop configuration. We are aimed to the highest coding standards only!

License

The gem is available as open source under the terms of the MIT License.