Ggtcf

I am writing a connect-four game for more OO and rspec practice. As part of my program, I would like to prompt the user to choose a column that they would like to put their game piece in. Here's that method:

def get_col_choice(input, output)
 output.print "Player #@player, choose a column from 0-6: " 
 input_string = input.gets.chomp
 begin
 col_choice = Integer(input_string)
 raise("The column you chose is out of bounds.") if out_of_bounds?(col_choice)
 raise("The column you chose is fully occupied.") if unavailable?(col_choice)
 return col_choice
 rescue TypeError, ArgumentError
 output.puts "Your choice of column is invalid. Try again."
 rescue RuntimeError => err
 puts err.message
 end
 get_col_choice(input, output)
end

In IRB, everything works as I planned. My hangup is in rspec where I am faced with a NoMethodError, which I think is coming from my recursive call to get_col_choice.

Can anyone help me understand what I can do to either improve get_col_choice or write the correct tests in Rspec? This is what my console output from my rspec file looks like:

Failures:

1) ConnectFourGame#get_col_choice notifies users which player gets to choose a column
 Failure/Error: $connect_four.get_col_choice(input, output)

 NoMethodError:
 undefined method `chomp' for nil:NilClass
 # /home/learnsometing/Desktop/the_Odin_Project/ruby/connect-four/lib/connect_four_game.rb:31:in `get_col_choice'
 # /home/learnsometing/Desktop/the_Odin_Project/ruby/connect-four/lib/connect_four_game.rb:42:in `get_col_choice'
 # ./connect_four_game_spec.rb:52:in `block (3 levels) in <top (required)>'

2) ConnectFourGame#get_col_choice returns the player's column choice
 Failure/Error: expect($connect_four.get_col_choice(input, output)).to eq(0)

 NoMethodError:
 undefined method `chomp' for nil:NilClass
 # /home/learnsometing/Desktop/the_Odin_Project/ruby/connect-four/lib/connect_four_game.rb:31:in `get_col_choice'
 # /home/learnsometing/Desktop/the_Odin_Project/ruby/connect-four/lib/connect_four_game.rb:42:in `get_col_choice'
 # ./connect_four_game_spec.rb:57:in `block (3 levels) in <top (required)>'

3) ConnectFourGame#get_col_choice notifies the user if the column they chose is already full of pieces
 Failure/Error: expect(output.string).to include("The column you chose is fully occupied.")
 expected "" to include "The column you chose is fully occupied."
 # ./connect_four_game_spec.rb:62:in `block (3 levels) in <top (required)>'

4) ConnectFourGame#get_col_choice notifies the user their input is invalid when a non-numeric string is entered
 Failure/Error: $connect_four.get_col_choice(input, output)

 NoMethodError:
 undefined method `chomp' for nil:NilClass
 # /home/learnsometing/Desktop/the_Odin_Project/ruby/connect-four/lib/connect_four_game.rb:31:in `get_col_choice'
 # /home/learnsometing/Desktop/the_Odin_Project/ruby/connect-four/lib/connect_four_game.rb:42:in `get_col_choice'
 # ./connect_four_game_spec.rb:67:in `block (3 levels) in <top (required)>'

5) ConnectFourGame#get_col_choice column choice is out of bounds notifies the user their column choice is out of bounds when col is greater than 6
 Failure/Error: $connect_four.get_col_choice(input, output)

 NoMethodError:
 undefined method `chomp' for nil:NilClass
 # /home/learnsometing/Desktop/the_Odin_Project/ruby/connect-four/lib/connect_four_game.rb:31:in `get_col_choice'
 # /home/learnsometing/Desktop/the_Odin_Project/ruby/connect-four/lib/connect_four_game.rb:42:in `get_col_choice'
 # ./connect_four_game_spec.rb:74:in `block (4 levels) in <top (required)>'

6) ConnectFourGame#get_col_choice column choice is out of bounds notifies the user their column choice is out of bounds when col is less than 0
 Failure/Error: $connect_four.get_col_choice(input, output)

 NoMethodError:
 undefined method `chomp' for nil:NilClass
 # /home/learnsometing/Desktop/the_Odin_Project/ruby/connect-four/lib/connect_four_game.rb:31:in `get_col_choice'
 # /home/learnsometing/Desktop/the_Odin_Project/ruby/connect-four/lib/connect_four_game.rb:42:in `get_col_choice'
 # ./connect_four_game_spec.rb:80:in `block (4 levels) in <top (required)>'

Finished in 0.02399 seconds (files took 0.1108 seconds to load)
12 examples, 6 failures

Failed examples:

rspec ./connect_four_game_spec.rb:51 # ConnectFourGame#get_col_choice notifies users which player gets to choose a column
rspec ./connect_four_game_spec.rb:56 # ConnectFourGame#get_col_choice returns the player's column choice
rspec ./connect_four_game_spec.rb:60 # ConnectFourGame#get_col_choice notifies the user if the column they chose is already full of pieces
rspec ./connect_four_game_spec.rb:66 # ConnectFourGame#get_col_choice notifies the user their input is invalid when a non-numeric string is entered
rspec ./connect_four_game_spec.rb:73 # ConnectFourGame#get_col_choice column choice is out of bounds notifies the user their column choice is out of bounds when col is greater than 6
rspec ./connect_four_game_spec.rb:79 # ConnectFourGame#get_col_choice column choice is out of bounds notifies the user their column choice is out of bounds when col is less than 0

Here are the tests I wrote for get_col_choice:

describe '#get_col_choice' do
 let(:output) StringIO.new 
 let(:input) StringIO.new("0n") 
 it 'notifies users which player gets to choose a column' do
 $connect_four.get_col_choice(input, output)
 expect(output.string).to include("Player 2, choose a column from 0-6: ")
 end

 it "returns the player's column choice" do
 expect($connect_four.get_col_choice(input, output)).to eq(0)
 end

 it 'notifies the user if the column they chose is already full of pieces' do
 6.times $connect_four.board.add_game_piece_to(0, "u2468") 
 expect(output.string).to include("The column you chose is fully occupied.")
 end

 let(:input) StringIO.new("!n") 
 it 'notifies the user their input is invalid when a non-numeric string is entered' do
 $connect_four.get_col_choice(input, output)
 expect(output.string).to include("Your choice of column is invalid. Try again.")
 end

 context 'column choice is out of bounds' do
 let(:input) StringIO.new("7n") 
 it 'notifies the user their column choice is out of bounds when col is greater than 6' do
 $connect_four.get_col_choice(input, output)
 expect(output.string).to include("The column you chose is out of bounds.")
 end

 let(:input) StringIO.new("-1n") 
 it 'notifies the user their column choice is out of bounds when col is less than 0' do
 $connect_four.get_col_choice(input, output)
 expect(output.string).to include("The column number you chose is out of bounds.")
 end
 end 
end

I was able to solve my problem by removing the input and output from get_col_choice:

def get_col_choice
 print "Player #@player, choose a column from 0-6: " 
 input_string = gets.chomp
 begin
 col_choice = Integer(input_string)
 raise("The column you chose is out of bounds.") if out_of_bounds?(col_choice)
 raise("The column you chose is fully occupied.") if @board.unavailable?(col_choice)
 return col_choice
 rescue TypeError, ArgumentError
 puts "Your choice of column is invalid. Try again." 
 rescue RuntimeError => err
 puts err.message
 end
 get_col_choice
end

In my rspec file, instead of using StringIO to inject the behavior I expected into get_col_choice, I stubbed gets to return the values I needed to trigger expected behaviors:

#code left out for brevity
before(:each) do
 @game = ConnectFourGame.new
end

describe '#get_col_choice' do
 before(:each) do
 allow($stdout).to receive(:write)
 @game.player = 1
 end

 context 'valid input' do
 before(:each) do
 allow(@game).to receive(:gets) "0n"
 end

 it 'notifies users which player gets to choose a column' do
 expect @game.get_col_choice .to output('Player 1, choose a column from 0-6: ').to_stdout
 end

 it "returns the user's column choice as an integer" do
 expect(@game.get_col_choice).to eq(0)
 end
 end

 context 'invalid input' do
 output_expectation = Proc.new expect @game.get_col_choice .to output(output).to_stdout 

 it 'notifies the user if the column they chose is already full of pieces' do
 allow(@game).to receive(:gets).and_return("0n", "1n")
 6.times @game.board.add_game_piece_to(0, "u2648") 
 output = "Player 1, choose a column from 0-6: The column you chose is fully occupied.nPlayer 1, choose a column from 0-6: "
 output_expectation
 end

 it 'notifies the user their input is invalid when a non-numeric string is entered' do
 allow(@game).to receive(:gets).and_return("foon", "0n")
 output = "Player 1, choose a column from 0-6: Your choice of column is invalid. Try again.nPlayer 1, choose a column from 0-6: "
 output_expectation
 end

 it 'notifies the user their column choice is out of bounds when col is greater than 6' do
 allow(@game).to receive(:gets).and_return("7n", "0n")
 output = "Player 1, choose a column from 0-6: The column you chose is out of bounds.nPlayer 1, choose a column from 0-6: "
 output_expectation
 end

 it 'notifies the user their column choice is out of bounds when col is less than 0' do
 allow(@game).to receive(:gets).and_return("-1n", "0n")
 output = "Player 1, choose a column from 0-6: The column you chose is out of bounds.nPlayer 1, choose a column from 0-6: "
 output_expectation
 end
 end 
end

The reason I received errors in my previous implementation of get_col_choice was because after StringIO received my first input string, it closed, resulting in a value of nil that I tried to call gets on.