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

describe "Enumerable#slice_before" do
  before :each do
    @enum = EnumerableSpecs::Numerous.new(7,6,5,4,3,2,1)
  end

  describe "when given an argument and no block" do
    it "calls === on the argument to determine when to yield" do
      arg = mock "filter"
      arg.should_receive(:===).and_return(false, true, false, false, false, true, false)
      e = @enum.slice_before(arg)
      e.should be_an_instance_of(enumerator_class)
      e.to_a.should == [[7], [6, 5, 4, 3], [2, 1]]
    end

    it "doesn't yield an empty array if the filter matches the first entry or the last entry" do
      arg = mock "filter"
      arg.should_receive(:===).and_return(true).exactly(7)
      e = @enum.slice_before(arg)
      e.to_a.should == [[7], [6], [5], [4], [3], [2], [1]]
    end

    it "uses standard boolean as a test" do
      arg = mock "filter"
      arg.should_receive(:===).and_return(false, :foo, nil, false, false, 42, false)
      e = @enum.slice_before(arg)
      e.to_a.should == [[7], [6, 5, 4, 3], [2, 1]]
    end
  end

  describe "when given a block" do
    describe "and no argument" do
      it "calls the block to determine when to yield" do
        e = @enum.slice_before{|i| i == 6 || i == 2}
        e.should be_an_instance_of(enumerator_class)
        e.to_a.should == [[7], [6, 5, 4, 3], [2, 1]]
      end
    end

    describe "and an argument" do
      it "calls the block with a copy of that argument" do
        arg = [:foo]
        first = nil
        e = @enum.slice_before(arg) do |i, init|
          init.should == arg
          init.should_not equal(arg)
          first = init
          i == 6 || i == 2
        end
        e.should be_an_instance_of(enumerator_class)
        e.to_a.should == [[7], [6, 5, 4, 3], [2, 1]]
        e = @enum.slice_before(arg) do |i, init|
          init.should_not equal(first)
        end
        e.to_a
      end

      quarantine! do # need to double-check with ruby-core. Might be wrong or too specific
        it "duplicates the argument directly without calling dup" do
          arg = EnumerableSpecs::Undupable.new
          e = @enum.slice_before(arg) do |i, init|
            init.initialize_dup_called.should be_true
            false
          end
          e.to_a.should == [[7, 6, 5, 4, 3, 2, 1]]
        end
      end
    end
  end

  it "raises an Argument error when given an incorrect number of arguments" do
    lambda { @enum.slice_before("one", "two") }.should raise_error(ArgumentError)
    lambda { @enum.slice_before }.should raise_error(ArgumentError)
  end
end
