block_spec.rb

require File.expand_path('../../spec_helper', __FILE__)
require File.expand_path('../fixtures/block', __FILE__)

describe "A block" do
  before :each do
    @y = BlockSpecs::Yielder.new
  end

  it "captures locals from the surrounding scope" do
    var = 1
    @y.z { var }.should == 1
  end

  ruby_version_is ""..."1.9" do
    it "overwrites a captured local when used as an argument" do
      var = 1
      @y.s(2) { |var| var }.should == 2
      var.should == 2
    end
  end

  ruby_version_is "1.9" do
    it "does not capture a local when an argument has the same name" do
      var = 1
      @y.s(2) { |var| var }.should == 2
      var.should == 1
    end
  end

  describe "taking zero arguments" do
    it "does not raise an exception when no values are yielded" do
      @y.z { 1 }.should == 1
    end

    it "does not raise an exception when values are yielded" do
      @y.s(0) { 1 }.should == 1
    end
  end

  describe "taking || arguments" do
    it "does not raise an exception when no values are yielded" do
      @y.z { || 1 }.should == 1
    end

    it "does not raise an exception when values are yielded" do
      @y.s(0) { || 1 }.should == 1
    end
  end

  describe "taking |a| arguments" do
    it "assigns nil to the argument when no values are yielded" do
      @y.z { |a| a }.should be_nil
    end

    it "assigns the value yielded to the argument" do
      @y.s(1) { |a| a }.should == 1
    end

    it "does not call #to_ary to convert a single yielded object to an Array" do
      obj = mock("block yield to_ary")
      obj.should_not_receive(:to_ary)

      @y.s(obj) { |a| a }.should equal(obj)
    end

    ruby_version_is ""..."1.9" do
      it "assigns all the values yielded to the argument as an Array" do
        @y.m(1, 2) { |a| a }.should == [1, 2]
      end
    end

    ruby_version_is "1.9" do
      it "assigns the first value yielded to the argument" do
        @y.m(1, 2) { |a| a }.should == 1
      end
    end

    it "does not destructure a single Array value" do
      @y.s([1, 2]) { |a| a }.should == [1, 2]
    end
  end

  describe "taking |a, b| arguments" do
    it "assgins nil to the arguments when no values are yielded" do
      @y.z { |a, b| [a, b] }.should == [nil, nil]
    end

    it "assigns one value yielded to the first argument" do
      @y.s(1) { |a, b| [a, b] }.should == [1, nil]
    end

    it "assigns the first two values yielded to the arguments" do
      @y.m(1, 2, 3) { |a, b| [a, b] }.should == [1, 2]
    end

    it "does not destructure an Array value as one of several values yielded" do
      @y.m([1, 2], 3, 4) { |a, b| [a, b] }.should == [[1, 2], 3]
    end

    it "assigns 'nil' and 'nil' to the arguments when a single, empty Array is yielded" do
      @y.s([]) { |a, b| [a, b] }.should == [nil, nil]
    end

    it "assigns the element of a single element Array to the first argument" do
      @y.s([1]) { |a, b| [a, b] }.should == [1, nil]
      @y.s([nil]) { |a, b| [a, b] }.should == [nil, nil]
      @y.s([[]]) { |a, b| [a, b] }.should == [[], nil]
    end

    it "destructures a single Array value yielded" do
      @y.s([1, 2, 3]) { |a, b| [a, b] }.should == [1, 2]
    end

    ruby_version_is ""..."1.9" do
      it "does not destructure a splatted Array" do
        @y.r([[]]) { |a, b| [a, b] }.should == [[], nil]
        @y.r([[1]]) { |a, b| [a, b] }.should == [[1], nil]
      end
    end

    ruby_version_is "1.9" do
      it "destructures a splatted Array" do
        @y.r([[]]) { |a, b| [a, b] }.should == [nil, nil]
        @y.r([[1]]) { |a, b| [a, b] }.should == [1, nil]
      end
    end

    it "calls #to_ary to convert a single yielded object to an Array" do
      obj = mock("block yield to_ary")
      obj.should_receive(:to_ary).and_return([1, 2])

      @y.s(obj) { |a, b| [a, b] }.should == [1, 2]
    end

    it "does not call #to_ary if the single yielded object is an Array" do
      obj = [1, 2]
      obj.should_not_receive(:to_ary)

      @y.s(obj) { |a, b| [a, b] }.should == [1, 2]
    end

    it "does not call #to_ary if the object does not respond to #to_ary" do
      obj = mock("block yield no to_ary")

      @y.s(obj) { |a, b| [a, b] }.should == [obj, nil]
    end

    it "raises an TypeError if #to_ary does not return an Array" do
      obj = mock("block yield to_ary invalid")
      obj.should_receive(:to_ary).and_return(1)

      lambda { @y.s(obj) { |a, b| } }.should raise_error(TypeError)
    end
  end

  describe "taking |a, *b| arguments" do
    it "assigns 'nil' and '[]' to the arguments when no values are yielded" do
      @y.z { |a, *b| [a, b] }.should == [nil, []]
    end

    it "assigns all yielded values after the first to the rest argument" do
      @y.m(1, 2, 3) { |a, *b| [a, b] }.should == [1, [2, 3]]
    end

    it "assigns 'nil' and '[]' to the arguments when a single, empty Array is yielded" do
      @y.s([]) { |a, *b| [a, b] }.should == [nil, []]
    end

    it "assigns the element of a single element Array to the first argument" do
      @y.s([1]) { |a, *b| [a, b] }.should == [1, []]
      @y.s([nil]) { |a, *b| [a, b] }.should == [nil, []]
      @y.s([[]]) { |a, *b| [a, b] }.should == [[], []]
    end

    ruby_version_is ""..."1.9" do
      it "does not destructure a splatted Array" do
        @y.r([[]]) { |a, *b| [a, b] }.should == [[], []]
        @y.r([[1]]) { |a, *b| [a, b] }.should == [[1], []]
      end
    end

    ruby_version_is "1.9" do
      it "destructures a splatted Array" do
        @y.r([[]]) { |a, *b| [a, b] }.should == [nil, []]
        @y.r([[1]]) { |a, *b| [a, b] }.should == [1, []]
      end
    end

    it "destructures a single Array value assigning the remaining values to the rest argument" do
      @y.s([1, 2, 3]) { |a, *b| [a, b] }.should == [1, [2, 3]]
    end

    it "calls #to_ary to convert a single yielded object to an Array" do
      obj = mock("block yield to_ary")
      obj.should_receive(:to_ary).and_return([1, 2])

      @y.s(obj) { |a, *b| [a, b] }.should == [1, [2]]
    end

    it "does not call #to_ary if the single yielded object is an Array" do
      obj = [1, 2]
      obj.should_not_receive(:to_ary)

      @y.s(obj) { |a, *b| [a, b] }.should == [1, [2]]
    end

    it "does not call #to_ary if the object does not respond to #to_ary" do
      obj = mock("block yield no to_ary")

      @y.s(obj) { |a, *b| [a, b] }.should == [obj, []]
    end

    it "raises an TypeError if #to_ary does not return an Array" do
      obj = mock("block yield to_ary invalid")
      obj.should_receive(:to_ary).and_return(1)

      lambda { @y.s(obj) { |a, *b| } }.should raise_error(TypeError)
    end
  end

  describe "taking |*| arguments" do
    it "does not raise an exception when no values are yielded" do
      @y.z { |*| 1 }.should == 1
    end

    it "does not raise an exception when values are yielded" do
      @y.s(0) { |*| 1 }.should == 1
    end

    it "does not call #to_ary if the single yielded object is an Array" do
      obj = [1, 2]
      obj.should_not_receive(:to_ary)

      @y.s(obj) { |*| 1 }.should == 1
    end

    it "does not call #to_ary if the object does not respond to #to_ary" do
      obj = mock("block yield no to_ary")

      @y.s(obj) { |*| 1 }.should == 1
    end

    ruby_version_is ""..."1.9" do
      it "calls #to_ary to convert a single yielded object to an Array" do
        obj = mock("block yield to_ary")
        obj.should_receive(:to_ary).and_return([1, 2])

        @y.s(obj) { |*| 1 }.should == 1
      end

      it "raises an TypeError if #to_ary does not return an Array" do
        obj = mock("block yield to_ary invalid")
        obj.should_receive(:to_ary).and_return(1)

        lambda { @y.s(obj) { |*| } }.should raise_error(TypeError)
      end
    end

    ruby_version_is "1.9" do
      it "does not call #to_ary to convert a single yielded object to an Array" do
        obj = mock("block yield to_ary")
        obj.should_not_receive(:to_ary)

        @y.s(obj) { |*| 1 }.should == 1
      end
    end
  end

  describe "taking |*a| arguments" do
    it "assigns '[]' to the argument when no values are yielded" do
      @y.z { |*a| a }.should == []
    end

    it "assigns a single value yielded to the argument as an Array" do
      @y.s(1) { |*a| a }.should == [1]
    end

    it "assigns all the values passed to the argument as an Array" do
      @y.m(1, 2, 3) { |*a| a }.should == [1, 2, 3]
    end

    it "assigns '[[]]' to the argument when passed an empty Array" do
      @y.s([]) { |*a| a }.should == [[]]
    end

    it "assigns a single Array value passed to the argument by wrapping it in an Array" do
      @y.s([1, 2, 3]) { |*a| a }.should == [[1, 2, 3]]
    end

    it "does not call #to_ary if the single yielded object is an Array" do
      obj = [1, 2]
      obj.should_not_receive(:to_ary)

      @y.s(obj) { |*a| a }.should == [[1, 2]]
    end

    it "does not call #to_ary if the object does not respond to #to_ary" do
      obj = mock("block yield no to_ary")

      @y.s(obj) { |*a| a }.should == [obj]
    end

    ruby_version_is ""..."1.9" do
      it "calls #to_ary to convert a single yielded object to an Array" do
        obj = mock("block yield to_ary")
        obj.should_receive(:to_ary).and_return([1, 2])

        @y.s(obj) { |*a| a }.should == [obj]
      end

      it "raises an TypeError if #to_ary does not return an Array" do
        obj = mock("block yield to_ary invalid")
        obj.should_receive(:to_ary).and_return(1)

        lambda { @y.s(obj) { |*a| } }.should raise_error(TypeError)
      end
    end

    ruby_version_is "1.9" do
      it "does not call #to_ary to convert a single yielded object to an Array" do
        obj = mock("block yield to_ary")
        obj.should_not_receive(:to_ary)

        @y.s(obj) { |*a| a }.should == [obj]
      end
    end
  end

  describe "taking |a, | arguments" do
    it "assigns nil to the argument when no values are yielded" do
      @y.z { |a, | a }.should be_nil
    end

    it "assgins the argument a single value yielded" do
      @y.s(1) { |a, | a }.should == 1
    end

    it "assigns the argument the first value yielded" do
      @y.m(1, 2) { |a, | a }.should == 1
    end

    it "assigns the argument the first of several values yielded when it is an Array" do
      @y.m([1, 2], 3) { |a, | a }.should == [1, 2]
    end

    it "assigns nil to the argument when passed an empty Array" do
      @y.s([]) { |a, | a }.should be_nil
    end

    it "assigns the argument the first element of the Array when passed a single Array" do
      @y.s([1, 2]) { |a, | a }.should == 1
    end

    it "calls #to_ary to convert a single yielded object to an Array" do
      obj = mock("block yield to_ary")
      obj.should_receive(:to_ary).and_return([1, 2])

      @y.s(obj) { |a, | a }.should == 1
    end

    it "does not call #to_ary if the single yielded object is an Array" do
      obj = [1, 2]
      obj.should_not_receive(:to_ary)

      @y.s(obj) { |a, | a }.should == 1
    end

    it "does not call #to_ary if the object does not respond to #to_ary" do
      obj = mock("block yield no to_ary")

      @y.s(obj) { |a, | a }.should == obj
    end

    it "raises an TypeError if #to_ary does not return an Array" do
      obj = mock("block yield to_ary invalid")
      obj.should_receive(:to_ary).and_return(1)

      lambda { @y.s(obj) { |a, | } }.should raise_error(TypeError)
    end
  end

  describe "taking |(a, b)| arguments" do
    it "assigns nil to the arguments when yielded no values" do
      @y.z { |(a, b)| [a, b] }.should == [nil, nil]
    end

    it "destructures a single Array value yielded" do
      @y.s([1, 2]) { |(a, b)| [a, b] }.should == [1, 2]
    end

    it "calls #to_ary to convert a single yielded object to an Array" do
      obj = mock("block yield to_ary")
      obj.should_receive(:to_ary).and_return([1, 2])

      @y.s(obj) { |(a, b)| [a, b] }.should == [1, 2]
    end

    it "does not call #to_ary if the single yielded object is an Array" do
      obj = [1, 2]
      obj.should_not_receive(:to_ary)

      @y.s(obj) { |(a, b)| [a, b] }.should == [1, 2]
    end

    it "does not call #to_ary if the object does not respond to #to_ary" do
      obj = mock("block yield no to_ary")

      @y.s(obj) { |(a, b)| [a, b] }.should == [obj, nil]
    end

    it "raises an TypeError if #to_ary does not return an Array" do
      obj = mock("block yield to_ary invalid")
      obj.should_receive(:to_ary).and_return(1)

      lambda { @y.s(obj) { |(a, b)| } }.should raise_error(TypeError)
    end
  end

  describe "taking |(a, b), c| arguments" do
    it "assigns nil to the arguments when yielded no values" do
      @y.z { |(a, b), c| [a, b, c] }.should == [nil, nil, nil]
    end

    it "destructures a single one-level Array value yielded" do
      @y.s([1, 2]) { |(a, b), c| [a, b, c] }.should == [1, nil, 2]
    end

    it "destructures a single multi-level Array value yielded" do
      @y.s([[1, 2, 3], 4]) { |(a, b), c| [a, b, c] }.should == [1, 2, 4]
    end

    it "calls #to_ary to convert a single yielded object to an Array" do
      obj = mock("block yield to_ary")
      obj.should_receive(:to_ary).and_return([1, 2])

      @y.s(obj) { |(a, b), c| [a, b, c] }.should == [1, nil, 2]
    end

    it "does not call #to_ary if the single yielded object is an Array" do
      obj = [1, 2]
      obj.should_not_receive(:to_ary)

      @y.s(obj) { |(a, b), c| [a, b, c] }.should == [1, nil, 2]
    end

    it "does not call #to_ary if the object does not respond to #to_ary" do
      obj = mock("block yield no to_ary")

      @y.s(obj) { |(a, b), c| [a, b, c] }.should == [obj, nil, nil]
    end

    it "raises an TypeError if #to_ary does not return an Array" do
      obj = mock("block yield to_ary invalid")
      obj.should_receive(:to_ary).and_return(1)

      lambda { @y.s(obj) { |(a, b), c| } }.should raise_error(TypeError)
    end
  end
end

language_version __FILE__, "block"