marian13

Byebug syntax highlighting. Works for v10.0.0 and higher.

• Yet another hack how to enable the syntax highlighting for the byebug gem.

• Works for v10.0.0 and higher.

• Place the content of byebug_syntax_highlighting.rb somewhere in your codebase (Inside an initializer for example, if you are using Rails).

• Do not forget to include byebug and rouge to the Gemfile as well.

marian13

Object that raises error on any method call

Useful for mocking in tests.

marian13

• Transparent GitHub Avatar.

marian13

# Temporarily redirects STDOUT and STDERR to /dev/null
# but does print exceptions should there occur any.
# Call as:
#   suppress_output { puts 'never printed' }
#
def suppress_output
  original_stderr = $stderr.clone
  original_stdout = $stdout.clone
  $stderr.reopen(File.new('/dev/null', 'w'))
  $stdout.reopen(File.new('/dev/null', 'w'))

marian13

Delete and recreate primary key

Delete a row with a primary key, recreate that row with the same primary key.

Preparation

mysql -u root
# Welcome to the MySQL monitor.  Commands end with ; or \g.
# Your MySQL connection id is 26

marian13

Deep Merge Concat

Can be useful for "inheritance" in YAML.

marian13

A proof that unless condition_1 && condition_2 is the same as if !condition_1 || !condition_2.

• Create a file.

  touch test.rb

• Paste the following content inside of it.

marian13

Do not accidentally create global methods in Ruby

Here is an example:

It is common to make such mistake in spec_helper, Rakefile, etc.

marian13

Module#include has incompatibilities between Ruby 2 and 3

Try to run the following example:

puts RUBY_VERSION

module IncludeModule
  def foo
 "foo from `IncludeModule`"

marian13

Not predictable equal? behaviour

• Try to guess what is the return value of question.equal?("hurting yourself") in test_1.rb.

• true? Are you sure?

• Run test_1.rb

ruby test_1.rb