require_relative '../spec_helper'

describe "A method send" do
  evaluate <<-ruby do
      def m(a) a end
    ruby

    a = b = m 1
    a.should == 1
    b.should == 1
  end

  context "with a single splatted Object argument" do
    before :all do
      def m(a) a end
    end

    it "does not call #to_ary" do
      x = mock("splat argument")
      x.should_not_receive(:to_ary)

      m(*x).should equal(x)
    end

    it "calls #to_a" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return([1])

      m(*x).should == 1
    end

    it "wraps the argument in an Array if #to_a returns nil" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(nil)

      m(*x).should == x
    end

    it "raises a TypeError if #to_a does not return an Array" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(1)

      -> { m(*x) }.should raise_error(TypeError)
    end
  end

  context "with a leading splatted Object argument" do
    before :all do
      def m(a, b, *c, d, e) [a, b, c, d, e] end
    end

    it "does not call #to_ary" do
      x = mock("splat argument")
      x.should_not_receive(:to_ary)

      m(*x, 1, 2, 3).should == [x, 1, [], 2, 3]
    end

    it "calls #to_a" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return([1])

      m(*x, 2, 3, 4).should == [1, 2, [], 3, 4]
    end

    it "wraps the argument in an Array if #to_a returns nil" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(nil)

      m(*x, 2, 3, 4).should == [x, 2, [], 3, 4]
    end

    it "raises a TypeError if #to_a does not return an Array" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(1)

      -> { m(*x, 2, 3) }.should raise_error(TypeError)
    end
  end

  context "with a middle splatted Object argument" do
    before :all do
      def m(a, b, *c, d, e) [a, b, c, d, e] end
    end

    it "does not call #to_ary" do
      x = mock("splat argument")
      x.should_not_receive(:to_ary)

      m(1, 2, *x, 3, 4).should == [1, 2, [x], 3, 4]
    end

    it "calls #to_a" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return([5, 6, 7])

      m(1, 2, *x, 3).should == [1, 2, [5, 6], 7, 3]
    end

    it "wraps the argument in an Array if #to_a returns nil" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(nil)

      m(1, 2, *x, 4).should == [1, 2, [], x, 4]
    end

    it "raises a TypeError if #to_a does not return an Array" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(1)

      -> { m(1, *x, 2, 3) }.should raise_error(TypeError)
    end

    it "copies the splatted array" do
      args = [3, 4]
      m(1, 2, *args, 4, 5).should == [1, 2, [3, 4], 4, 5]
      m(1, 2, *args, 4, 5)[2].should_not equal(args)
    end

    it "allows an array being splatted to be modified by another argument" do
      args = [3, 4]
      m(1, args.shift, *args, 4, 5).should == [1, 3, [4], 4, 5]
    end
  end

  context "with a trailing splatted Object argument" do
    before :all do
      def m(a, *b, c) [a, b, c] end
    end

    it "does not call #to_ary" do
      x = mock("splat argument")
      x.should_not_receive(:to_ary)

      m(1, 2, *x).should == [1, [2], x]
    end

    it "calls #to_a" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return([5, 6, 7])

      m(1, 2, *x).should == [1, [2, 5, 6], 7]
    end

    it "wraps the argument in an Array if #to_a returns nil" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(nil)

      m(1, 2, *x, 4).should == [1, [2, x], 4]
    end

    it "raises a TypeError if #to_a does not return an Array" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(1)

      -> { m(1, 2, *x) }.should raise_error(TypeError)
    end
  end

  context "with a block argument" do
    before :all do
      def m(x)
        if block_given?
          [true, yield(x + 'b')]
        else
          [false]
        end
      end
    end

    it "that refers to a proc passes the proc as the block" do
      m('a', &-> y { y + 'c'}).should == [true, 'abc']
    end

    it "that is nil passes no block" do
      m('a', &nil).should == [false]
    end
  end
end

describe "An element assignment method send" do
  before :each do
    ScratchPad.clear
  end

  context "with a single splatted Object argument" do
    before :all do
      @o = mock("element set receiver")
      def @o.[]=(a, b) ScratchPad.record [a, b] end
    end

    it "does not call #to_ary" do
      x = mock("splat argument")
      x.should_not_receive(:to_ary)

      (@o[*x] = 1).should == 1
      ScratchPad.recorded.should == [x, 1]
    end

    it "calls #to_a" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return([1])

      (@o[*x] = 2).should == 2
      ScratchPad.recorded.should == [1, 2]
    end

    it "wraps the argument in an Array if #to_a returns nil" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(nil)

      (@o[*x] = 1).should == 1
      ScratchPad.recorded.should == [x, 1]
    end

    it "raises a TypeError if #to_a does not return an Array" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(1)

      -> { @o[*x] = 1 }.should raise_error(TypeError)
    end
  end

  context "with a leading splatted Object argument" do
    before :all do
      @o = mock("element set receiver")
      def @o.[]=(a, b, *c, d, e) ScratchPad.record [a, b, c, d, e] end
    end

    it "does not call #to_ary" do
      x = mock("splat argument")
      x.should_not_receive(:to_ary)

      (@o[*x, 2, 3, 4] = 1).should == 1
      ScratchPad.recorded.should == [x, 2, [3], 4, 1]
    end

    it "calls #to_a" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return([1, 2, 3])

      (@o[*x, 4, 5] = 6).should == 6
      ScratchPad.recorded.should == [1, 2, [3, 4], 5, 6]
    end

    it "wraps the argument in an Array if #to_a returns nil" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(nil)

      (@o[*x, 2, 3, 4] = 5).should == 5
      ScratchPad.recorded.should == [x, 2, [3], 4, 5]
    end

    it "raises a TypeError if #to_a does not return an Array" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(1)

      -> { @o[*x, 2, 3] = 4 }.should raise_error(TypeError)
    end
  end

  context "with a middle splatted Object argument" do
    before :all do
      @o = mock("element set receiver")
      def @o.[]=(a, b, *c, d, e) ScratchPad.record [a, b, c, d, e] end
    end

    it "does not call #to_ary" do
      x = mock("splat argument")
      x.should_not_receive(:to_ary)

      (@o[1, *x, 2, 3] = 4).should == 4
      ScratchPad.recorded.should == [1, x, [2], 3, 4]
    end

    it "calls #to_a" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return([2, 3])

      (@o[1, *x, 4] = 5).should == 5
      ScratchPad.recorded.should == [1, 2, [3], 4, 5]
    end

    it "wraps the argument in an Array if #to_a returns nil" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(nil)

      (@o[1, 2, *x, 3] = 4).should == 4
      ScratchPad.recorded.should == [1, 2, [x], 3, 4]
    end

    it "raises a TypeError if #to_a does not return an Array" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(1)

      -> { @o[1, 2, *x, 3] = 4 }.should raise_error(TypeError)
    end
  end

  context "with a trailing splatted Object argument" do
    before :all do
      @o = mock("element set receiver")
      def @o.[]=(a, b, *c, d, e) ScratchPad.record [a, b, c, d, e] end
    end

    it "does not call #to_ary" do
      x = mock("splat argument")
      x.should_not_receive(:to_ary)

      (@o[1, 2, 3, 4, *x] = 5).should == 5
      ScratchPad.recorded.should == [1, 2, [3, 4], x, 5]
    end

    it "calls #to_a" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return([4, 5])

      (@o[1, 2, 3, *x] = 6).should == 6
      ScratchPad.recorded.should == [1, 2, [3, 4], 5, 6]
    end

    it "wraps the argument in an Array if #to_a returns nil" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(nil)

      (@o[1, 2, 3, *x] = 4).should == 4
      ScratchPad.recorded.should == [1, 2, [3], x, 4]
    end

    it "raises a TypeError if #to_a does not return an Array" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(1)

      -> { @o[1, 2, 3, *x] = 4 }.should raise_error(TypeError)
    end
  end
end

describe "An attribute assignment method send" do
  context "with a single splatted Object argument" do
    before :all do
      @o = mock("element set receiver")
      def @o.m=(a, b) [a, b] end
    end

    it "does not call #to_ary" do
      x = mock("splat argument")
      x.should_not_receive(:to_ary)

      (@o.send :m=, *x, 1).should == [x, 1]
    end

    it "calls #to_a" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return([1])

      (@o.send :m=, *x, 2).should == [1, 2]
    end

    it "wraps the argument in an Array if #to_a returns nil" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(nil)

      (@o.send :m=, *x, 1).should == [x, 1]
    end

    it "raises a TypeError if #to_a does not return an Array" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(1)

      -> { @o.send :m=, *x, 1 }.should raise_error(TypeError)
    end
  end

  context "with a leading splatted Object argument" do
    before :all do
      @o = mock("element set receiver")
      def @o.m=(a, b, *c, d, e) [a, b, c, d, e] end
    end

    it "does not call #to_ary" do
      x = mock("splat argument")
      x.should_not_receive(:to_ary)

      (@o.send :m=, *x, 2, 3, 4, 1).should == [x, 2, [3], 4, 1]
    end

    it "calls #to_a" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return([1, 2, 3])

      (@o.send :m=, *x, 4, 5, 6).should == [1, 2, [3, 4], 5, 6]
    end

    it "wraps the argument in an Array if #to_a returns nil" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(nil)

      (@o.send :m=, *x, 2, 3, 4, 5).should == [x, 2, [3], 4, 5]
    end

    it "raises a TypeError if #to_a does not return an Array" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(1)

      -> { @o.send :m=, *x, 2, 3, 4 }.should raise_error(TypeError)
    end
  end

  context "with a middle splatted Object argument" do
    before :all do
      @o = mock("element set receiver")
      def @o.m=(a, b, *c, d, e) [a, b, c, d, e] end
    end

    it "does not call #to_ary" do
      x = mock("splat argument")
      x.should_not_receive(:to_ary)

      (@o.send :m=, 1, *x, 2, 3, 4).should == [1, x, [2], 3, 4]
    end

    it "calls #to_a" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return([2, 3])

      (@o.send :m=, 1, *x, 4, 5).should == [1, 2, [3], 4, 5]
    end

    it "wraps the argument in an Array if #to_a returns nil" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(nil)

      (@o.send :m=, 1, 2, *x, 3, 4).should == [1, 2, [x], 3, 4]
    end

    it "raises a TypeError if #to_a does not return an Array" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(1)

      -> { @o.send :m=, 1, 2, *x, 3, 4 }.should raise_error(TypeError)
    end
  end

  context "with a trailing splatted Object argument" do
    before :all do
      @o = mock("element set receiver")
      def @o.m=(a, b, *c, d, e) [a, b, c, d, e] end
    end

    it "does not call #to_ary" do
      x = mock("splat argument")
      x.should_not_receive(:to_ary)

      (@o.send :m=, 1, 2, 3, 4, *x, 5).should == [1, 2, [3, 4], x, 5]
    end

    it "calls #to_a" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return([4, 5])

      (@o.send :m=, 1, 2, 3, *x, 6).should == [1, 2, [3, 4], 5, 6]
    end

    it "wraps the argument in an Array if #to_a returns nil" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(nil)

      (@o.send :m=, 1, 2, 3, *x, 4).should == [1, 2, [3], x, 4]
    end

    it "raises a TypeError if #to_a does not return an Array" do
      x = mock("splat argument")
      x.should_receive(:to_a).and_return(1)

      -> { @o.send :m=, 1, 2, 3, *x, 4 }.should raise_error(TypeError)
    end
  end
end

describe "A method" do
  SpecEvaluate.desc = "for definition"

  context "assigns no local variables" do
    evaluate <<-ruby do
        def m
        end
      ruby

      m.should be_nil
    end

    evaluate <<-ruby do
        def m()
        end
      ruby

      m.should be_nil
    end
  end

  context "assigns local variables from method parameters" do
    evaluate <<-ruby do
        def m(a) a end
      ruby

      m((args = 1, 2, 3)).should equal(args)
    end

    evaluate <<-ruby do
        def m((a)) a end
      ruby

      m(1).should == 1
      m([1, 2, 3]).should == 1
    end

    evaluate <<-ruby do
        def m((*a, b)) [a, b] end
      ruby

      m(1).should == [[], 1]
      m([1, 2, 3]).should == [[1, 2], 3]
    end

    evaluate <<-ruby do
        def m(a=1) a end
      ruby

      m().should == 1
      m(2).should == 2
    end

    evaluate <<-ruby do
        def m() end
      ruby

      m().should be_nil
      m(*[]).should be_nil
      m(**{}).should be_nil
    end

    evaluate <<-ruby do
        def m(*) end
      ruby

      m().should be_nil
      m(1).should be_nil
      m(1, 2, 3).should be_nil
    end

    evaluate <<-ruby do
        def m(*a) a end
      ruby

      m().should == []
      m(1).should == [1]
      m(1, 2, 3).should == [1, 2, 3]
      m(*[]).should == []
      m(**{}).should == []
    end

    evaluate <<-ruby do
        def m(a:) a end
      ruby

      -> { m() }.should raise_error(ArgumentError)
      m(a: 1).should == 1
      suppress_keyword_warning do
        -> { m("a" => 1, a: 1) }.should raise_error(ArgumentError)
      end
    end

    evaluate <<-ruby do
        def m(a: 1) a end
      ruby

      m().should == 1
      m(a: 2).should == 2
    end

    evaluate <<-ruby do
        def m(**) end
      ruby

      m().should be_nil
      m(a: 1, b: 2).should be_nil
      -> { m(1) }.should raise_error(ArgumentError)
    end

    evaluate <<-ruby do
        def m(**k) k end
      ruby

      m().should == {}
      m(a: 1, b: 2).should == { a: 1, b: 2 }
      m(*[]).should == {}
      m(**{}).should == {}
      suppress_warning {
        eval "m(**{a: 1, b: 2}, **{a: 4, c: 7})"
      }.should == { a: 4, b: 2, c: 7 }
      -> { m(2) }.should raise_error(ArgumentError)
    end

    evaluate <<-ruby do
      def m(**k); k end;
      ruby

      m("a" => 1).should == { "a" => 1 }
    end

    evaluate <<-ruby do
        def m(&b) b end
      ruby

      m { }.should be_an_instance_of(Proc)
    end

    evaluate <<-ruby do
        def m(a, b) [a, b] end
      ruby

      m(1, 2).should == [1, 2]
    end

    evaluate <<-ruby do
        def m(a, (b, c)) [a, b, c] end
      ruby

      m(1, 2).should == [1, 2, nil]
      m(1, [2, 3, 4]).should == [1, 2, 3]
    end

    evaluate <<-ruby do
        def m((a), (b)) [a, b] end
      ruby

      m(1, 2).should == [1, 2]
      m([1, 2], [3, 4]).should == [1, 3]
    end

    evaluate <<-ruby do
        def m((*), (*)) end
      ruby

      m(2, 3).should be_nil
      m([2, 3, 4], [5, 6]).should be_nil
      -> { m a: 1 }.should raise_error(ArgumentError)
    end

    evaluate <<-ruby do
        def m((*a), (*b)) [a, b] end
      ruby

      m(1, 2).should == [[1], [2]]
      m([1, 2], [3, 4]).should == [[1, 2], [3, 4]]
    end

    evaluate <<-ruby do
        def m((a, b), (c, d))
          [a, b, c, d]
        end
      ruby

      m(1, 2).should == [1, nil, 2, nil]
      m([1, 2, 3], [4, 5, 6]).should == [1, 2, 4, 5]
    end

    evaluate <<-ruby do
        def m((a, *b), (*c, d))
          [a, b, c, d]
        end
      ruby

      m(1, 2).should == [1, [], [], 2]
      m([1, 2, 3], [4, 5, 6]).should == [1, [2, 3], [4, 5], 6]
    end

    evaluate <<-ruby do
        def m((a, b, *c, d), (*e, f, g), (*h))
          [a, b, c, d, e, f, g, h]
        end
      ruby

      m(1, 2, 3).should == [1, nil, [], nil, [], 2, nil, [3]]
      result = m([1, 2, 3], [4, 5, 6, 7, 8], [9, 10])
      result.should == [1, 2, [], 3, [4, 5, 6], 7, 8, [9, 10]]
    end

    evaluate <<-ruby do
        def m(a, (b, (c, *d), *e))
          [a, b, c, d, e]
        end
      ruby

      m(1, 2).should == [1, 2, nil, [], []]
      m(1, [2, [3, 4, 5], 6, 7, 8]).should == [1, 2, 3, [4, 5], [6, 7, 8]]
    end

    evaluate <<-ruby do
        def m(a, (b, (c, *d, (e, (*f)), g), (h, (i, j))))
          [a, b, c, d, e, f, g, h, i, j]
        end
      ruby

      m(1, 2).should == [1, 2, nil, [], nil, [nil], nil, nil, nil, nil]
      result = m(1, [2, [3, 4, 5, [6, [7, 8]], 9], [10, [11, 12]]])
      result.should == [1, 2, 3, [4, 5], 6, [7, 8], 9, 10, 11, 12]
    end

    evaluate <<-ruby do
        def m(a, b=1) [a, b] end
      ruby

      m(2).should == [2, 1]
      m(1, 2).should == [1, 2]
    end

    evaluate <<-ruby do
        def m(a, *) a end
      ruby

      m(1).should == 1
      m(1, 2, 3).should == 1
    end

    evaluate <<-ruby do
        def m(a, *b) [a, b] end
      ruby

      m(1).should == [1, []]
      m(1, 2, 3).should == [1, [2, 3]]
    end

    evaluate <<-ruby do
        def m(a, b:) [a, b] end
      ruby

      m(1, b: 2).should == [1, 2]
      suppress_keyword_warning do
        -> { m("a" => 1, b: 2) }.should raise_error(ArgumentError)
      end
    end

    ruby_version_is ""..."3.0" do
      evaluate <<-ruby do
          def m(a, b: 1) [a, b] end
        ruby

        m(2).should == [2, 1]
        m(1, b: 2).should == [1, 2]
        suppress_keyword_warning do
          m("a" => 1, b: 2).should == [{"a" => 1, b: 2}, 1]
        end
      end

      evaluate <<-ruby do
          def m(a, **) a end
        ruby

        m(1).should == 1
        m(1, a: 2, b: 3).should == 1
        suppress_keyword_warning do
          m("a" => 1, b: 2).should == {"a" => 1, b: 2}
        end
      end

      evaluate <<-ruby do
          def m(a, **k) [a, k] end
        ruby

        m(1).should == [1, {}]
        m(1, a: 2, b: 3).should == [1, {a: 2, b: 3}]
        suppress_keyword_warning do
          m("a" => 1, b: 2).should == [{"a" => 1, b: 2}, {}]
        end
      end
    end

    ruby_version_is "3.0" do
      evaluate <<-ruby do
          def m(a, b: 1) [a, b] end
        ruby

        m(2).should == [2, 1]
        m(1, b: 2).should == [1, 2]
        -> { m("a" => 1, b: 2) }.should raise_error(ArgumentError)
      end

      evaluate <<-ruby do
          def m(a, **) a end
        ruby

        m(1).should == 1
        m(1, a: 2, b: 3).should == 1
        -> { m("a" => 1, b: 2) }.should raise_error(ArgumentError)
      end

      evaluate <<-ruby do
          def m(a, **k) [a, k] end
        ruby

        m(1).should == [1, {}]
        m(1, a: 2, b: 3).should == [1, {a: 2, b: 3}]
        -> { m("a" => 1, b: 2) }.should raise_error(ArgumentError)
      end
    end

    evaluate <<-ruby do
        def m(a, &b) [a, b] end
      ruby

      m(1).should == [1, nil]
      m(1, &(l = -> {})).should == [1, l]
    end

    evaluate <<-ruby do
        def m(a=1, b) [a, b] end
      ruby

      m(2).should == [1, 2]
      m(2, 3).should == [2, 3]
    end

    evaluate <<-ruby do
        def m(a=1, *) a end
      ruby

      m().should == 1
      m(2, 3, 4).should == 2
    end

    evaluate <<-ruby do
        def m(a=1, *b) [a, b] end
      ruby

      m().should == [1, []]
      m(2, 3, 4).should == [2, [3, 4]]
    end

    evaluate <<-ruby do
        def m(a=1, (b, c)) [a, b, c] end
      ruby

      m(2).should == [1, 2, nil]
      m(2, 3).should == [2, 3, nil]
      m(2, [3, 4, 5]).should == [2, 3, 4]
    end

    evaluate <<-ruby do
        def m(a=1, (b, (c, *d))) [a, b, c, d] end
      ruby

      m(2).should == [1, 2, nil, []]
      m(2, 3).should == [2, 3, nil, []]
      m(2, [3, [4, 5, 6], 7]).should == [2, 3, 4, [5, 6]]
    end

    evaluate <<-ruby do
        def m(a=1, (b, (c, *d), *e)) [a, b, c, d, e] end
      ruby

      m(2).should == [1, 2, nil, [], []]
      m(2, [3, 4, 5, 6]).should == [2, 3, 4, [], [5, 6]]
      m(2, [3, [4, 5, 6], 7]).should == [2, 3, 4, [5, 6], [7]]
    end

    evaluate <<-ruby do
        def m(a=1, (b), (c)) [a, b, c] end
      ruby

      m(2, 3).should == [1, 2, 3]
      m(2, 3, 4).should == [2, 3, 4]
      m(2, [3, 4], [5, 6, 7]).should == [2, 3, 5]
    end

    evaluate <<-ruby do
        def m(a=1, (*b), (*c)) [a, b, c] end
      ruby

      -> { m() }.should raise_error(ArgumentError)
      -> { m(2) }.should raise_error(ArgumentError)
      m(2, 3).should == [1, [2], [3]]
      m(2, [3, 4], [5, 6]).should == [2, [3, 4], [5, 6]]
    end

    evaluate <<-ruby do
        def m(a=1, (b, c), (d, e)) [a, b, c, d, e] end
      ruby

      m(2, 3).should == [1, 2, nil, 3, nil]
      m(2, [3, 4, 5], [6, 7, 8]).should == [2, 3, 4, 6, 7]
    end

    evaluate <<-ruby do
        def m(a=1, (b, *c), (*d, e))
          [a, b, c, d, e]
        end
      ruby

      m(1, 2).should == [1, 1, [], [], 2]
      m(1, [2, 3], [4, 5, 6]).should == [1, 2, [3], [4, 5], 6]
    end

    evaluate <<-ruby do
        def m(a=1, (b, *c), (d, (*e, f)))
          [a, b, c, d, e, f]
        end
      ruby

      m(1, 2).should == [1, 1, [], 2, [], nil]
      m(nil, nil).should == [1, nil, [], nil, [], nil]
      result = m([1, 2, 3], [4, 5, 6], [7, 8, 9])
      result.should == [[1, 2, 3], 4, [5, 6], 7, [], 8]
    end

    ruby_version_is ""..."3.0" do
      evaluate <<-ruby do
          def m(a=1, b:) [a, b] end
        ruby

        m(b: 2).should == [1, 2]
        m(2, b: 1).should == [2, 1]
        suppress_keyword_warning do
          m("a" => 1, b: 2).should == [{"a" => 1}, 2]
        end
      end

      evaluate <<-ruby do
          def m(a=1, b: 2) [a, b] end
        ruby

        m().should == [1, 2]
        m(2).should == [2, 2]
        m(b: 3).should == [1, 3]
        suppress_keyword_warning do
          m("a" => 1, b: 2).should == [{"a" => 1}, 2]
        end
      end
    end

    ruby_version_is "3.0" do
      evaluate <<-ruby do
          def m(a=1, b:) [a, b] end
        ruby

        m(b: 2).should == [1, 2]
        m(2, b: 1).should == [2, 1]
        -> { m("a" => 1, b: 2) }.should raise_error(ArgumentError)
      end

      evaluate <<-ruby do
          def m(a=1, b: 2) [a, b] end
        ruby

        m().should == [1, 2]
        m(2).should == [2, 2]
        m(b: 3).should == [1, 3]
        -> { m("a" => 1, b: 2) }.should raise_error(ArgumentError)
      end
    end

    evaluate <<-ruby do
        def m(a=1, **) a end
      ruby

      m().should == 1
      m(2, a: 1, b: 0).should == 2
      m("a" => 1, a: 2).should == 1
    end

    evaluate <<-ruby do
        def m(a=1, **k) [a, k] end
      ruby

      m().should == [1, {}]
      m(2, a: 1, b: 2).should == [2, {a: 1, b: 2}]
    end

    evaluate <<-ruby do
        def m(a=1, &b) [a, b] end
      ruby

      m().should == [1, nil]
      m(&(l = -> {})).should == [1, l]

      p = -> {}
      l = mock("to_proc")
      l.should_receive(:to_proc).and_return(p)
      m(&l).should == [1, p]
    end

    evaluate <<-ruby do
        def m(*, a) a end
      ruby

      m(1).should == 1
      m(1, 2, 3).should == 3
    end

    evaluate <<-ruby do
        def m(*a, b) [a, b] end
      ruby

      m(1).should == [[], 1]
      m(1, 2, 3).should == [[1, 2], 3]
    end

    ruby_version_is ""...'3.0' do
      evaluate <<-ruby do
          def m(*, a:) a end
        ruby

        m(a: 1).should == 1
        m(1, 2, a: 3).should == 3
        suppress_keyword_warning do
          m("a" => 1, a: 2).should == 2
        end
      end

      evaluate <<-ruby do
          def m(*a, b:) [a, b] end
        ruby

        m(b: 1).should == [[], 1]
        m(1, 2, b: 3).should == [[1, 2], 3]
        suppress_keyword_warning do
          m("a" => 1, b: 2).should == [[{"a" => 1}], 2]
        end
      end

      evaluate <<-ruby do
          def m(*, a: 1) a end
        ruby

        m().should == 1
        m(1, 2).should == 1
        m(a: 2).should == 2
        m(1, a: 2).should == 2
        suppress_keyword_warning do
          m("a" => 1, a: 2).should == 2
        end
      end

      evaluate <<-ruby do
          def m(*a, b: 1) [a, b] end
        ruby

        m().should == [[], 1]
        m(1, 2, 3, b: 4).should == [[1, 2, 3], 4]
        suppress_keyword_warning do
          m("a" => 1, b: 2).should == [[{"a" => 1}], 2]
        end

        a = mock("splat")
        a.should_not_receive(:to_ary)
        m(*a).should == [[a], 1]
      end

      evaluate <<-ruby do
          def m(*a, **) a end
        ruby

        m().should == []
        m(1, 2, 3, a: 4, b: 5).should == [1, 2, 3]
        m("a" => 1, a: 1).should == []
        m(1, **{a: 2}).should == [1]

        h = mock("keyword splat")
        h.should_receive(:to_hash)
        -> { m(**h) }.should raise_error(TypeError)
      end

      evaluate <<-ruby do
          def m(*, **k) k end
        ruby

        m().should == {}
        m(1, 2, 3, a: 4, b: 5).should == {a: 4, b: 5}
        m("a" => 1, a: 1).should == {"a" => 1, a: 1}

        h = mock("keyword splat")
        h.should_receive(:to_hash).and_return({a: 1})
        suppress_warning do
          m(h).should == {a: 1}
        end
      end

      evaluate <<-ruby do
          def m(a = nil, **k) [a, k] end
        ruby

        m().should == [nil, {}]
        m("a" => 1).should == [nil, {"a" => 1}]
        m(a: 1).should == [nil, {a: 1}]
        m("a" => 1, a: 1).should == [nil, {"a" => 1, a: 1}]
        m({ "a" => 1 }, a: 1).should == [{"a" => 1}, {a: 1}]
        suppress_warning do
          m({a: 1}, {}).should == [{a: 1}, {}]

          h = {"a" => 1, b: 2}
          m(h).should == [{"a" => 1}, {b: 2}]
          h.should == {"a" => 1, b: 2}

          h = {"a" => 1}
          m(h).first.should == h

          h = {}
          r = m(h)
          r.first.should be_nil
          r.last.should == {}

          hh = {}
          h = mock("keyword splat empty hash")
          h.should_receive(:to_hash).and_return(hh)
          r = m(h)
          r.first.should be_nil
          r.last.should == {}

          h = mock("keyword splat")
          h.should_receive(:to_hash).and_return({"a" => 1, a: 2})
          m(h).should == [{"a" => 1}, {a: 2}]
        end
      end

      evaluate <<-ruby do
          def m(*a, **k) [a, k] end
        ruby

        m().should == [[], {}]
        m(1).should == [[1], {}]
        m(a: 1, b: 2).should == [[], {a: 1, b: 2}]
        m(1, 2, 3, a: 2).should == [[1, 2, 3], {a: 2}]

        m("a" => 1).should == [[], {"a" => 1}]
        m(a: 1).should == [[], {a: 1}]
        m("a" => 1, a: 1).should == [[], {"a" => 1, a: 1}]
        m({ "a" => 1 }, a: 1).should == [[{"a" => 1}], {a: 1}]
        suppress_warning do
          m({a: 1}, {}).should == [[{a: 1}], {}]
        end
        m({a: 1}, {"a" => 1}).should == [[{a: 1}, {"a" => 1}], {}]

        bo = BasicObject.new
        def bo.to_a; [1, 2, 3]; end
        def bo.to_hash; {:b => 2, :c => 3}; end

        m(*bo, **bo).should == [[1, 2, 3], {:b => 2, :c => 3}]
      end

      evaluate <<-ruby do
          def m(*, a:) a end
        ruby

        m(a: 1).should == 1
        m(1, 2, a: 3).should == 3
        suppress_keyword_warning do
          m("a" => 1, a: 2).should == 2
        end
      end

      evaluate <<-ruby do
          def m(*a, b:) [a, b] end
        ruby

        m(b: 1).should == [[], 1]
        m(1, 2, b: 3).should == [[1, 2], 3]
        suppress_keyword_warning do
          m("a" => 1, b: 2).should == [[{"a" => 1}], 2]
        end
      end

      evaluate <<-ruby do
          def m(*, a: 1) a end
        ruby

        m().should == 1
        m(1, 2).should == 1
        m(a: 2).should == 2
        m(1, a: 2).should == 2
        suppress_keyword_warning do
          m("a" => 1, a: 2).should == 2
        end
      end

      evaluate <<-ruby do
          def m(*a, b: 1) [a, b] end
        ruby

        m().should == [[], 1]
        m(1, 2, 3, b: 4).should == [[1, 2, 3], 4]
        suppress_keyword_warning do
          m("a" => 1, b: 2).should == [[{"a" => 1}], 2]
        end

        a = mock("splat")
        a.should_not_receive(:to_ary)
        m(*a).should == [[a], 1]
      end

      evaluate <<-ruby do
          def m(*a, **) a end
        ruby

        m().should == []
        m(1, 2, 3, a: 4, b: 5).should == [1, 2, 3]
        m("a" => 1, a: 1).should == []
        m(1, **{a: 2}).should == [1]

        h = mock("keyword splat")
        h.should_receive(:to_hash)
        -> { m(**h) }.should raise_error(TypeError)
      end

      evaluate <<-ruby do
          def m(*, **k) k end
        ruby

        m().should == {}
        m(1, 2, 3, a: 4, b: 5).should == {a: 4, b: 5}
        m("a" => 1, a: 1).should == {"a" => 1, a: 1}

        h = mock("keyword splat")
        h.should_receive(:to_hash).and_return({a: 1})
        suppress_keyword_warning do
          m(h).should == {a: 1}
        end
      end

      evaluate <<-ruby do
          def m(a = nil, **k) [a, k] end
        ruby

        m().should == [nil, {}]
        m("a" => 1).should == [nil, {"a" => 1}]
        m(a: 1).should == [nil, {a: 1}]
        m("a" => 1, a: 1).should == [nil, {"a" => 1, a: 1}]
        m({ "a" => 1 }, a: 1).should == [{"a" => 1}, {a: 1}]
        suppress_keyword_warning do
          m({a: 1}, {}).should == [{a: 1}, {}]
        end

        h = {"a" => 1, b: 2}
        suppress_keyword_warning do
          m(h).should == [{"a" => 1}, {b: 2}]
        end
        h.should == {"a" => 1, b: 2}

        h = {"a" => 1}
        m(h).first.should == h

        h = {}
        suppress_keyword_warning do
          m(h).should == [nil, {}]
        end

        hh = {}
        h = mock("keyword splat empty hash")
        h.should_receive(:to_hash).and_return({a: 1})
        suppress_keyword_warning do
          m(h).should == [nil, {a: 1}]
        end

        h = mock("keyword splat")
        h.should_receive(:to_hash).and_return({"a" => 1})
        m(h).should == [h, {}]
      end

      evaluate <<-ruby do
          def m(*a, **k) [a, k] end
        ruby

        m().should == [[], {}]
        m(1).should == [[1], {}]
        m(a: 1, b: 2).should == [[], {a: 1, b: 2}]
        m(1, 2, 3, a: 2).should == [[1, 2, 3], {a: 2}]

        m("a" => 1).should == [[], {"a" => 1}]
        m(a: 1).should == [[], {a: 1}]
        m("a" => 1, a: 1).should == [[], {"a" => 1, a: 1}]
        m({ "a" => 1 }, a: 1).should == [[{"a" => 1}], {a: 1}]
        suppress_keyword_warning do
          m({a: 1}, {}).should == [[{a: 1}], {}]
        end
        m({a: 1}, {"a" => 1}).should == [[{a: 1}, {"a" => 1}], {}]

        bo = BasicObject.new
        def bo.to_a; [1, 2, 3]; end
        def bo.to_hash; {:b => 2, :c => 3}; end

        m(*bo, **bo).should == [[1, 2, 3], {:b => 2, :c => 3}]
      end
    end

    evaluate <<-ruby do
        def m(*, &b) b end
      ruby

      m().should be_nil
      m(1, 2, 3, 4).should be_nil
      m(&(l = ->{})).should equal(l)
    end

    evaluate <<-ruby do
        def m(*a, &b) [a, b] end
      ruby

      m().should == [[], nil]
      m(1).should == [[1], nil]
      m(1, 2, 3, &(l = -> {})).should == [[1, 2, 3], l]
    end

    evaluate <<-ruby do
        def m(a:, b:) [a, b] end
      ruby

      m(a: 1, b: 2).should == [1, 2]
      suppress_keyword_warning do
        -> { m("a" => 1, a: 1, b: 2) }.should raise_error(ArgumentError)
      end
    end

    evaluate <<-ruby do
        def m(a:, b: 1) [a, b] end
      ruby

      m(a: 1).should == [1, 1]
      m(a: 1, b: 2).should == [1, 2]
      suppress_keyword_warning do
        -> { m("a" => 1, a: 1, b: 2) }.should raise_error(ArgumentError)
      end
    end

    evaluate <<-ruby do
        def m(a:, **) a end
      ruby

      m(a: 1).should == 1
      m(a: 1, b: 2).should == 1
      m("a" => 1, a: 1, b: 2).should == 1
    end

    evaluate <<-ruby do
        def m(a:, **k) [a, k] end
      ruby

      m(a: 1).should == [1, {}]
      m(a: 1, b: 2, c: 3).should == [1, {b: 2, c: 3}]
      m("a" => 1, a: 1, b: 2).should == [1, {"a" => 1, b: 2}]
    end

    evaluate <<-ruby do
        def m(a:, &b) [a, b] end
      ruby

      m(a: 1).should == [1, nil]
      m(a: 1, &(l = ->{})).should == [1, l]
    end

    evaluate <<-ruby do
        def m(a: 1, b:) [a, b] end
      ruby

      m(b: 0).should == [1, 0]
      m(b: 2, a: 3).should == [3, 2]
    end

    evaluate <<-ruby do
        def m(a: def m(a: 1) a end, b:)
          [a, b]
        end
      ruby

      m(a: 2, b: 3).should == [2, 3]
      m(b: 1).should == [:m, 1]

      # Note the default value of a: in the original method.
      m().should == 1
    end

    evaluate <<-ruby do
        def m(a: 1, b: 2) [a, b] end
      ruby

      m().should == [1, 2]
      m(b: 3, a: 4).should == [4, 3]
    end

    evaluate <<-ruby do
        def m(a: 1, **) a end
      ruby

      m().should == 1
      m(a: 2, b: 1).should == 2
    end

    evaluate <<-ruby do
        def m(a: 1, **k) [a, k] end
      ruby

      m(b: 2, c: 3).should == [1, {b: 2, c: 3}]
    end

    evaluate <<-ruby do
        def m(a: 1, &b) [a, b] end
      ruby

      m(&(l = ->{})).should == [1, l]
      m().should == [1, nil]
    end

    evaluate <<-ruby do
        def m(**, &b) b end
      ruby

      m(a: 1, b: 2, &(l = ->{})).should == l
    end

    evaluate <<-ruby do
        def m(**k, &b) [k, b] end
      ruby

      m(a: 1, b: 2).should == [{ a: 1, b: 2}, nil]
    end

    evaluate <<-ruby do
        def m(a, b=1, *c, (*d, (e)), f: 2, g:, h:, **k, &l)
          [a, b, c, d, e, f, g, h, k, l]
        end
      ruby

      result = m(9, 8, 7, 6, f: 5, g: 4, h: 3, &(l = ->{}))
      result.should == [9, 8, [7], [], 6, 5, 4, 3, {}, l]
    end

    evaluate <<-ruby do
        def m(a, b=1, *c, d, e:, f: 2, g:, **k, &l)
          [a, b, c, d, e, f, g, k, l]
        end
      ruby

      result = m(1, 2, e: 3, g: 4, h: 5, i: 6, &(l = ->{}))
      result.should == [1, 1, [], 2, 3, 2, 4, { h: 5, i: 6 }, l]
    end

    evaluate <<-ruby do
      def m(a, **nil); a end;
      ruby

      m({a: 1}).should == {a: 1}
      m({"a" => 1}).should == {"a" => 1}

      -> { m(a: 1) }.should raise_error(ArgumentError)
      -> { m(**{a: 1}) }.should raise_error(ArgumentError)
      -> { m("a" => 1) }.should raise_error(ArgumentError)
    end

    ruby_version_is ''...'3.0' do
      evaluate <<-ruby do
          def m(a, b = nil, c = nil, d, e: nil, **f)
            [a, b, c, d, e, f]
          end
        ruby

        result = m(1, 2)
        result.should == [1, nil, nil, 2, nil, {}]

        suppress_warning do
          result = m(1, 2, {foo: :bar})
          result.should == [1, nil, nil, 2, nil, {foo: :bar}]
        end

        result = m(1, {foo: :bar})
        result.should == [1, nil, nil, {foo: :bar}, nil, {}]
      end
    end

    ruby_version_is '3.0' do
      evaluate <<-ruby do
          def m(a, b = nil, c = nil, d, e: nil, **f)
            [a, b, c, d, e, f]
          end
        ruby

        result = m(1, 2)
        result.should == [1, nil, nil, 2, nil, {}]

        result = m(1, 2, {foo: :bar})
        result.should == [1, 2, nil, {foo: :bar}, nil, {}]

        result = m(1, {foo: :bar})
        result.should == [1, nil, nil, {foo: :bar}, nil, {}]
      end
    end
  end

  context 'when passing an empty keyword splat to a method that does not accept keywords' do
    evaluate <<-ruby do
        def m(*a); a; end
      ruby

      h = {}
      m(**h).should == []
    end
  end

  ruby_version_is ''...'3.0' do
    context 'when passing an empty keyword splat to a method that does not accept keywords' do
      evaluate <<-ruby do
          def m(a); a; end
        ruby
        h = {}

        -> do
          m(**h).should == {}
        end.should complain(/warning: Passing the keyword argument as the last hash parameter is deprecated/)
      end
    end
  end

  ruby_version_is ''...'3.0' do
    context "assigns keyword arguments from a passed Hash without modifying it" do
      evaluate <<-ruby do
          def m(a: nil); a; end
        ruby

        options = {a: 1}.freeze
        -> do
          suppress_warning do
            m(options).should == 1
          end
        end.should_not raise_error
        options.should == {a: 1}
      end
    end
  end

  ruby_version_is '3.0' do
    context 'when passing an empty keyword splat to a method that does not accept keywords' do
      evaluate <<-ruby do
          def m(a); a; end
        ruby
        h = {}

        -> do
          m(**h).should == {}
        end.should raise_error(ArgumentError)
      end
    end

    context "raises ArgumentError if passing hash as keyword arguments" do
      evaluate <<-ruby do
          def m(a: nil); a; end
        ruby

        options = {a: 1}.freeze
        -> do
          m(options)
        end.should raise_error(ArgumentError)
      end
    end
  end

  it "assigns the last Hash to the last optional argument if the Hash contains non-Symbol keys and is not passed as keywords" do
    def m(a = nil, b = {}, v: false)
      [a, b, v]
    end

    h = { "key" => "value" }
    m(:a, h).should == [:a, h, false]
    m(:a, h, v: true).should == [:a, h, true]
    m(v: true).should == [nil, {}, true]
  end
end

describe "A method call with a space between method name and parentheses" do
  before(:each) do
    def m(*args)
      args
    end

    def n(value, &block)
      [value, block.call]
    end
  end

  context "when no arguments provided" do
    it "assigns nil" do
      args = m ()
      args.should == [nil]
    end
  end

  context "when a single argument provided" do
    it "assigns it" do
      args = m (1 == 1 ? true : false)
      args.should == [true]
    end
  end

  context "when 2+ arguments provided" do
    it "raises a syntax error" do
      -> {
        eval("m (1, 2)")
      }.should raise_error(SyntaxError)

      -> {
        eval("m (1, 2, 3)")
      }.should raise_error(SyntaxError)
    end
  end

  it "allows to pass a block with curly braces" do
    args = n () { :block_value }
    args.should == [nil, :block_value]

    args = n (1) { :block_value }
    args.should == [1, :block_value]
  end

  it "allows to pass a block with do/end" do
    args = n () do
      :block_value
    end
    args.should == [nil, :block_value]

    args = n (1) do
      :block_value
    end
    args.should == [1, :block_value]
  end
end

describe "An array-dereference method ([])" do
  SpecEvaluate.desc = "for definition"

  context "received the passed-in block" do
    evaluate <<-ruby do
        def [](*, &b)
          b.call
        end
    ruby
      pr = proc {:ok}

      self[&pr].should == :ok
      self['foo', &pr].should == :ok
      self.[](&pr).should == :ok
      self.[]('foo', &pr).should == :ok
    end

    evaluate <<-ruby do
        def [](*)
          yield
        end
    ruby
      pr = proc {:ok}

      self[&pr].should == :ok
      self['foo', &pr].should == :ok
      self.[](&pr).should == :ok
      self.[]('foo', &pr).should == :ok
    end
  end
end

ruby_version_is "3.0" do
  describe "An endless method definition" do
    context "without arguments" do
      evaluate <<-ruby do
          def m() = 42
        ruby

        m.should == 42
      end
    end

    context "with arguments" do
      evaluate <<-ruby do
          def m(a, b) = a + b
        ruby

        m(1, 4).should == 5
      end
    end

    context "with multiline body" do
      evaluate <<-ruby do
          def m(n) =
            if n > 2
              m(n - 2) + m(n - 1)
            else
              1
            end
        ruby

        m(6).should == 8
      end
    end

    context "with args forwarding" do
      evaluate <<-ruby do
          def mm(word, num:)
            word * num
          end

          def m(...) = mm(...) + mm(...)
        ruby

        m("meow", num: 2).should == "meow" * 4
      end
    end
  end

  describe "Keyword arguments are now separated from positional arguments" do
    context "when the method has only positional parameters" do
      it "treats incoming keyword arguments as positional for compatibility" do
        def foo(a, b, c, hsh)
          hsh[:key]
        end

        foo(1, 2, 3, key: 42).should == 42
      end
    end

    context "when the method takes a ** parameter" do
      it "captures the passed literal keyword arguments" do
        def foo(a, b, c, **hsh)
          hsh[:key]
        end

        foo(1, 2, 3, key: 42).should == 42
      end

      it "captures the passed ** keyword arguments" do
        def foo(a, b, c, **hsh)
          hsh[:key]
        end

        h = { key: 42 }
        foo(1, 2, 3, **h).should == 42
      end

      it "does not convert a positional Hash to keyword arguments" do
        def foo(a, b, c, **hsh)
          hsh[:key]
        end

        -> {
          foo(1, 2, 3, { key: 42 })
        }.should raise_error(ArgumentError, 'wrong number of arguments (given 4, expected 3)')
      end
    end

    context "when the method takes a key: parameter" do
      context "when it's called with a positional Hash and no **" do
        it "raises ArgumentError" do
          def foo(a, b, c, key: 1)
            key
          end

          -> {
            foo(1, 2, 3, { key: 42 })
          }.should raise_error(ArgumentError, 'wrong number of arguments (given 4, expected 3)')
        end
      end

      context "when it's called with **" do
        it "captures the passed keyword arguments" do
          def foo(a, b, c, key: 1)
            key
          end

          h = { key: 42 }
          foo(1, 2, 3, **h).should == 42
        end
      end
    end
  end
end

ruby_version_is "3.1" do
  describe "kwarg with omitted value in a method call" do
    context "accepts short notation 'kwarg' in method call" do
      evaluate <<-ruby do
          def call(*args, **kwargs) = [args, kwargs]
        ruby

        a, b, c = 1, 2, 3
        arr, h = eval('call a:')
        h.should == {a: 1}
        arr.should == []

        arr, h = eval('call(a:, b:, c:)')
        h.should == {a: 1, b: 2, c: 3}
        arr.should == []

        arr, h = eval('call(a:, b: 10, c:)')
        h.should == {a: 1, b: 10, c: 3}
        arr.should == []
      end
    end

    context "with methods and local variables" do
      evaluate <<-ruby do
          def call(*args, **kwargs) = [args, kwargs]

          def bar
            "baz"
          end

          def foo(val)
            call bar:, val:
          end
        ruby

        foo(1).should == [[], {bar: "baz", val: 1}]
      end
    end
  end
end