raygervais · July 7, 2019 22:04
diff --git a/building_objects.rb b/building_objects.rb
 # Desired Behavior Module

 # Unit Testing, Why and How

 # MiniTest Example
 class FizzBuzzTest < MiniTest::Test
  def setup
    @fizz_buzz = FizzBuzz.new
  end	
  
  def test_three
    assert_equal "1, 2, Fizz", @fizz_buzz.talk(3)
  end
  
  def test_five
    assert_equal "1, 2, Fizz, 4, Buzz", @fizz_buzz.talk(5)
  end
 end

 # Rspec Example (Same tests)
 describe FizzBuzz do
  it "replaces divisors of 3 with Fizz" do
    expect(subject.talk(3)).to eq "1, 2, Fizz"
  end
  
  it "replaces divisors of 5 with Buzz" do
    expect(subject.talk(5)).to eq "1, 2, Fizz, 4, Buzz"
  end
 end

 # Out First Unit Test using MiniTest

 # movie.rb
 class Movie 
  # Built-in language getters and setters
  attr_accessor :director, :genre, :release_date, :rotten_tomatoes, :title

  def initialize(csv_row)
    @director = csv_row[:director]
    @genre = csv_row[:genre]
    @title = csv_row[:title]
    @release_date = csv_row[:release_date]
    @rotten_tomatoes = csv_row[:rotten_tomatoes]
  end
  
 end	

 # movie_test.rb
 require 'minitest/autorun'
 require_relative 'movie'

 class MovieTest < MiniTest::test
  def setup
    @movie = Movie.new({
      :title => "Star Wars",
      :genre => "Science Fiction",
      :director => "George Lucas",
      :release_date => "1977-05-25",
      :rotten_tomatoes => "93",
      })
  end
  
  def test_director
    assert_equal "George Lucas", @movie.director
  end
  
  def test_genre
    assert_equal "Science Fiction", @movie.genre
  end
  
  def test_rotten_tomatoes
    assert_equal 93, @movie.rotten_tomatoes
  end
  
  def test_title
    assert_equal "Star Wars", @movie.title
  end
 end

diff --git a/common_block_patterns.rb b/common_block_patterns.rb
 # DB Transaction Example
 database.transaction do
  from_account.subtract_balance(100.0)
  to_account.add_balance(100.0)
 end

 # Async / Event Handler Example
 button.on_click do |click_event|
  create_new_user
 end

 # Functional Map Example
 [1, 2, 3, 4].map do |int|
  int * 2
 end

 # => 2, 4, 6, 8
diff --git a/common_conditional_blocks.rb b/common_conditional_blocks.rb
 # Predicate Method Conditional

 # Predicate methods return only true or false, 
 # and have a question mark at the end.
 if 4.even?
  puts "4 is even"
 else
  puts "4 is odd"
 end

 # With if, you can also utilize `unless`
 puts "4 is even" unless 4.odd?

 # Conditional Assignments
 def best_players
  @best_players ||= begin
    players = database.table(:players)
    sorted = players.order(:points)
    sorted.top(10)
  end
 end

diff --git a/conditional_blocks.rb b/conditional_blocks.rb
 # Common CSV Load into Rows Example
 lines = File.open("movie.csv", "r") do |file_handle|
  file_handle.readlines
 end

 rows = []
 lines.each do |line|
  # Chomp removes whitespace and newline characters
  # << adds directly to array
  rows << line.chomp.split(",")
 end

 # Adding Conditional to a block
 movies = []
 headers = nil

 rows.each do |row|
  # Only follow forward with logic if 
  # condition on the right is true (next / skip)
  # Can be read as: `skip this row if it is empty`
  next if row.empty?
  
  if headers.nil?
    header = row
  else
    # The zip method matches up values of the array 
    # from array passed in arguments:  movies << headers.zip(row)

    # For easier parsing, we'll utilize the Hash object to collapse the list of pairs.
    movies << Hash(headers.zip(row))
  end
 end

 put movies.first
 # => ["Title" => "Star Wars Episode IV: A New Hope", "Release Date" => "1977-05-25", ... ]
diff --git a/enumerable.rb b/enumerable.rb
 require 'csv'
 require_relative 'movies'

 rows = CSV.read('movies.csv', :headers => true, headers_converter => :symbol, :skip_blanks => true)

 # Map
 movies = rows.map { |row| Movie.new(row) }

 # Select
 # In this example, get movies which contain a rotten tomatoes score.
 with_rotten_scores = movies.select { |movie| movie.rotten_tomatoes > 0 }

 # Reduce
 average_rotten_score = with_rotten_scores.reduce(0.0) do |total, movie| 
  total + movie.rotten_tomatoes 
 end

 # Group By
 # In this example, get movie count released  by month
 movies_by_month = movies.group_by do |movie|
  movie.release_date.strftime("%B")
 end

 # Ruby allows you to break an array in the map arguments
 count_by_month = movies_by_month.map do |month, list|
  [month, list.size]
 end

 # Sort By
 # Using Ruby symbol to proc shortcut for last
 count_by_month_sorted = count_by_month.sort_by(&:last).reverse
 count_str = count_by_month.map { |pair| pair.join(": ")}.join("\n")

 # Refactor (clean Up via chaining data methods)
 count_by_month = movies.group_by do |movie|
  					movie.release_date.strftime("%B")
 				end.map do |month, list|
  					[month, list.size]
 				end.sort_by(&:last).reverse
 count_str = count_by_month.map { |pair| pair.join(": ")}.join("\n")
diff --git a/enumerable_extras.rb b/enumerable_extras.rb
 # A few extras

 [1,2,3,4,5].any?(&:even?) # => true
 [1,2,3,4,5].all?(&:even?) # => false
 [1,2,3,4,5].find(&:even?) # => 2
 [1,2,3,4,5].reject(&:even?) # => 1,3,5
diff --git a/read_file.rb b/read_file.rb
 # Common Read File Pattern
 file_handler = File.open(“movies.csv”, “r”)
 begin
 	lines = file_handle.readlines
 ensure 
 	file_handler.close
 end

 #Idiomatic Lambda Read File Block
 lines = File.open(“movies.csv”, “r”) do |file_handle| 
 	file_handle.readlines 
 end
diff --git a/symbols.rb b/symbols.rb
 # Symbols are minimalistic strings in Ruby, often started with a `:`
 # In some ways, symbols take the place of enums from other languages



 # Playing off of movie CSV example above
 require 'csv'

 movies = CSV.read('movies.csv', :headers => true, headers_converter => :symbol, :skip_blanks => true)
	# Desired Behavior Module

	# Unit Testing, Why and How

	# MiniTest Example
	class FizzBuzzTest < MiniTest::Test
	def setup
	@fizz_buzz = FizzBuzz.new
	end

	def test_three
	assert_equal "1, 2, Fizz", @fizz_buzz.talk(3)
	end

	def test_five
	assert_equal "1, 2, Fizz, 4, Buzz", @fizz_buzz.talk(5)
	end
	end

	# Rspec Example (Same tests)
	describe FizzBuzz do
	it "replaces divisors of 3 with Fizz" do
	expect(subject.talk(3)).to eq "1, 2, Fizz"
	end

	it "replaces divisors of 5 with Buzz" do
	expect(subject.talk(5)).to eq "1, 2, Fizz, 4, Buzz"
	end
	end

	# Out First Unit Test using MiniTest

	# movie.rb
	class Movie
	# Built-in language getters and setters
	attr_accessor :director, :genre, :release_date, :rotten_tomatoes, :title

	def initialize(csv_row)
	@director = csv_row[:director]
	@genre = csv_row[:genre]
	@title = csv_row[:title]
	@release_date = csv_row[:release_date]
	@rotten_tomatoes = csv_row[:rotten_tomatoes]
	end

	end

	# movie_test.rb
	require 'minitest/autorun'
	require_relative 'movie'

	class MovieTest < MiniTest::test
	def setup
	@movie = Movie.new({
	:title => "Star Wars",
	:genre => "Science Fiction",
	:director => "George Lucas",
	:release_date => "1977-05-25",
	:rotten_tomatoes => "93",
	})
	end

	def test_director
	assert_equal "George Lucas", @movie.director
	end

	def test_genre
	assert_equal "Science Fiction", @movie.genre
	end

	def test_rotten_tomatoes
	assert_equal 93, @movie.rotten_tomatoes
	end

	def test_title
	assert_equal "Star Wars", @movie.title
	end
	end
	# DB Transaction Example
	database.transaction do
	from_account.subtract_balance(100.0)
	to_account.add_balance(100.0)
	end

	# Async / Event Handler Example
	button.on_click do \|click_event\|
	create_new_user
	end

	# Functional Map Example
	[1, 2, 3, 4].map do \|int\|
	int * 2
	end

	# => 2, 4, 6, 8
	# Predicate Method Conditional

	# Predicate methods return only true or false,
	# and have a question mark at the end.
	if 4.even?
	puts "4 is even"
	else
	puts "4 is odd"
	end

	# With if, you can also utilize `unless`
	puts "4 is even" unless 4.odd?

	# Conditional Assignments
	def best_players
	@best_players \|\|= begin
	players = database.table(:players)
	sorted = players.order(:points)
	sorted.top(10)
	end
	end
	# Common CSV Load into Rows Example
	lines = File.open("movie.csv", "r") do \|file_handle\|
	file_handle.readlines
	end

	rows = []
	lines.each do \|line\|
	# Chomp removes whitespace and newline characters
	# << adds directly to array
	rows << line.chomp.split(",")
	end

	# Adding Conditional to a block
	movies = []
	headers = nil

	rows.each do \|row\|
	# Only follow forward with logic if
	# condition on the right is true (next / skip)
	# Can be read as: `skip this row if it is empty`
	next if row.empty?

	if headers.nil?
	header = row
	else
	# The zip method matches up values of the array
	# from array passed in arguments: movies << headers.zip(row)

	# For easier parsing, we'll utilize the Hash object to collapse the list of pairs.
	movies << Hash(headers.zip(row))
	end
	end

	put movies.first
	# => ["Title" => "Star Wars Episode IV: A New Hope", "Release Date" => "1977-05-25", ... ]
	require 'csv'
	require_relative 'movies'

	rows = CSV.read('movies.csv', :headers => true, headers_converter => :symbol, :skip_blanks => true)

	# Map
	movies = rows.map { \|row\| Movie.new(row) }

	# Select
	# In this example, get movies which contain a rotten tomatoes score.
	with_rotten_scores = movies.select { \|movie\| movie.rotten_tomatoes > 0 }

	# Reduce
	average_rotten_score = with_rotten_scores.reduce(0.0) do \|total, movie\|
	total + movie.rotten_tomatoes
	end

	# Group By
	# In this example, get movie count released by month
	movies_by_month = movies.group_by do \|movie\|
	movie.release_date.strftime("%B")
	end

	# Ruby allows you to break an array in the map arguments
	count_by_month = movies_by_month.map do \|month, list\|
	[month, list.size]
	end

	# Sort By
	# Using Ruby symbol to proc shortcut for last
	count_by_month_sorted = count_by_month.sort_by(&:last).reverse
	count_str = count_by_month.map { \|pair\| pair.join(": ")}.join("\n")

	# Refactor (clean Up via chaining data methods)
	count_by_month = movies.group_by do \|movie\|
	movie.release_date.strftime("%B")
	end.map do \|month, list\|
	[month, list.size]
	end.sort_by(&:last).reverse
	count_str = count_by_month.map { \|pair\| pair.join(": ")}.join("\n")
	# A few extras

	[1,2,3,4,5].any?(&:even?) # => true
	[1,2,3,4,5].all?(&:even?) # => false
	[1,2,3,4,5].find(&:even?) # => 2
	[1,2,3,4,5].reject(&:even?) # => 1,3,5
	# Common Read File Pattern
	file_handler = File.open(“movies.csv”, “r”)
	begin
	lines = file_handle.readlines
	ensure
	file_handler.close
	end

	#Idiomatic Lambda Read File Block
	lines = File.open(“movies.csv”, “r”) do \|file_handle\|
	file_handle.readlines
	end
	# Symbols are minimalistic strings in Ruby, often started with a `:`
	# In some ways, symbols take the place of enums from other languages



	# Playing off of movie CSV example above
	require 'csv'

	movies = CSV.read('movies.csv', :headers => true, headers_converter => :symbol, :skip_blanks => true)