JoshCheek

# app/controllers/users_controller.rb
class UsersController < ApplicationController
  def index
    render text: "Your IP is #{request.remote_ip}"
  end
end

# test/controllers/users_controller_test.rb
class UsersControllerTest < ActionController::TestCase
  test "should get index" do

JoshCheek

/* touch -- change modification and access times of files
   Copyright (C) 1987, 1989-1991, 1995-2005, 2007-2011 Free Software
   Foundation, Inc.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,

JoshCheek

Ruby in place of sed / awk

One of Ruby's major influences was Perl, leaving well equipped to replace bash, sed, and awk. Lets take a look at how to do that.

The -e flag

JoshCheek

# Read initial standard input from the data segment at the end of the file
# You can also see what is ultimately output down there
pos = DATA.pos          # => 1617
$stdin.reopen __FILE__  # => #<IO:/var/folders/7g/mbft22555w3_2nqs_h1kbglw0000gn/T/seeing_is_believing_temp_dir20161210-36802-czciw7/program.rb>
$stdin.seek pos, :SET   # => 0

# The commands that will be piped together
commands = [
  %w[cat],
  %w[tr a A],

JoshCheek

# these are reconstructed from a shell session without runnig them, so make
# sure you check that it's a sane thing to do before running it, I make no
# guarantees of fitness, and accept no liability. Run at your own risk.
sudo launchctl remove com.snap.SnapCameraRemover
rm -r ~/Library/Caches/Snap/
rm -r ~/Library/Caches/com.snap.SnapCamera/
rm -r ~/Library/Preferences/Snap/
rm ~/Library/Preferences/com.snap.SnapCamera.plist
rm ~/Library/Preferences/com.snap.Snap\ Camera.plist
sudo rm -rf /Applications/Snap\ Camera.app/

JoshCheek

• specs go in the "spec" directory
• specs end in "_spec.rb"
• toplevel begins with describe
• inside of a describe you have an it
• example is an alias for it
• inside of it blocks, you write your code and assertions
• run with $ rspec or $ rspec spec/some_spec.rb
• if you need common setup (e.g. add another dir to the load path), put into "spec/spec_helper.rb" and then `require "spec_helper" at the top of the spec
• using let will allow you to name a value that you want to call from your spec,

JoshCheek

# I submitted a bug report https://github.com/rails/rails/issues/34244
# b/c Rails was not honouring my `rescue_from` block which was causing my API to
# be inconsistent. I was told this is expected behaviour. I think it's probably
# fine for an HTML app where you control the form inputs. But for an API app,
# the API is public facing and very important, so Rails shouldn't have its own
# special errors that bypass my app's configuration and make my API inconsistent.
# 
# Decided it shouldn't be too difficult to handle this myself. So, here is my
# solution. It contains most of the important lessons I've learned about how to
# get a Rails API app setup. It removes Rails' params parsing and adds its own.

JoshCheek

# Helpers to make the code below easier to read
class Array
  def keywords?()    = Hash.ruby2_keywords_hash?(self[-1])
  def to_keywords!() = (self[-1] = Hash.ruby2_keywords_hash(self[-1]))
end

# Code to facilitate the examples below
def record_args(*args) = args
def call_this(val:)    = val

JoshCheek

puts Solution.new('1. Fizz Buzz', <<SOLUTION)
  def fizzbuzz(n)(n%15==0?'FizzBuzz':n%3==0?'Fizz':n%5==0?'Buzz':n).to_s end
SOLUTION
  .test { fizzbuzz 3  }.expect { |result| result == "Fizz"      }
  .test { fizzbuzz 10 }.expect { |result| result == "Buzz"      }
  .test { fizzbuzz 45 }.expect { |result| result == "FizzBuzz"  }
  .test { fizzbuzz 31 }.expect { |result| result == "31"        }

JoshCheek

require 'pg'
db = PG.connect dbname: 'josh_testing'
db.exec 'begin'

def db.exec(*)
  super.to_a
rescue
  $!.set_backtrace caller.drop(1)
  raise
end