require_relative '../../spec_helper'
require_relative 'shared/compose'

describe "Proc#<<" do
  it "returns a Proc that is the composition of self and the passed Proc" do
    upcase = proc { |s| s.upcase }
    succ = proc { |s| s.succ }

    (succ << upcase).call('Ruby').should == "RUBZ"
  end

  it "calls passed Proc with arguments and then calls self with result" do
    f = proc { |x| x * x }
    g = proc { |x| x + x }

    (f << g).call(2).should == 16
    (g << f).call(2).should == 8
  end

  it "accepts any callable object" do
    inc = proc { |n| n + 1 }

    double = Object.new
    def double.call(n); n * 2; end

    (inc << double).call(3).should == 7
  end

  it_behaves_like :proc_compose, :<<, -> { proc { |s| s.upcase } }

  describe "composition" do
    it "is a Proc" do
      f = proc { |x| x * x }
      g = proc { |x| x + x }

      (f << g).is_a?(Proc).should == true
      (f << g).should_not.lambda?
    end

    it "is a lambda when parameter is lambda" do
      f = -> x { x * x }
      g = proc { |x| x + x }
      lambda_proc = -> x { x }

      # lambda << proc
      (f << g).is_a?(Proc).should == true
      (f << g).should_not.lambda?

      # lambda << lambda
      (f << lambda_proc).is_a?(Proc).should == true
      (f << lambda_proc).should.lambda?

      # proc << lambda
      (g << f).is_a?(Proc).should == true
      (g << f).should.lambda?
    end

    it "may accept multiple arguments" do
      inc = proc { |n| n + 1 }
      mul = proc { |n, m| n * m }

      (inc << mul).call(2, 3).should == 7
    end

    it "passes blocks to the second proc" do
      ScratchPad.record []
      one = proc { |&arg| arg.call :one if arg }
      two = proc { |&arg| arg.call :two if arg }
      (one << two).call { |x| ScratchPad << x }
      ScratchPad.recorded.should == [:two]
    end
  end
end

describe "Proc#>>" do
  it "returns a Proc that is the composition of self and the passed Proc" do
    upcase = proc { |s| s.upcase }
    succ = proc { |s| s.succ }

    (succ >> upcase).call('Ruby').should == "RUBZ"
  end

  it "calls passed Proc with arguments and then calls self with result" do
    f = proc { |x| x * x }
    g = proc { |x| x + x }

    (f >> g).call(2).should == 8
    (g >> f).call(2).should == 16
  end

  it "accepts any callable object" do
    inc = proc { |n| n + 1 }

    double = Object.new
    def double.call(n); n * 2; end

    (inc >> double).call(3).should == 8
  end

  it_behaves_like :proc_compose, :>>, -> { proc { |s| s.upcase } }

  describe "composition" do
    it "is a Proc" do
      f = proc { |x| x * x }
      g = proc { |x| x + x }

      (f >> g).is_a?(Proc).should == true
      (f >> g).should_not.lambda?
    end

    it "is a Proc when other is lambda" do
      f = proc { |x| x * x }
      g = -> x { x + x }

      (f >> g).is_a?(Proc).should == true
      (f >> g).should_not.lambda?
    end

    it "is a lambda when self is lambda" do
      f = -> x { x * x }
      g = proc { |x| x + x }

      (f >> g).is_a?(Proc).should == true
      (f >> g).should.lambda?
    end

    it "may accept multiple arguments" do
      inc = proc { |n| n + 1 }
      mul = proc { |n, m| n * m }

      (mul >> inc).call(2, 3).should == 7
    end

    it "passes blocks to the first proc" do
      ScratchPad.record []
      one = proc { |&arg| arg.call :one if arg }
      two = proc { |&arg| arg.call :two if arg }
      (one >> two).call { |x| ScratchPad << x }
      ScratchPad.recorded.should == [:one]
    end
  end
end