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path: root/spec/ruby/core/enumerable/drop_while_spec.rb
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require File.expand_path('../../../spec_helper', __FILE__)
require File.expand_path('../fixtures/classes', __FILE__)
require File.expand_path('../shared/enumerable_enumeratorized', __FILE__)

describe "Enumerable#drop_while" do
  before :each do
    @enum = EnumerableSpecs::Numerous.new(3, 2, 1, :go)
  end

  it "returns an Enumerator if no block given" do
    @enum.drop_while.should be_an_instance_of(Enumerator)
  end

  it "returns no/all elements for {true/false} block" do
    @enum.drop_while{true}.should == []
    @enum.drop_while{false}.should == @enum.to_a
  end

  it "accepts returns other than true/false" do
    @enum.drop_while{1}.should == []
    @enum.drop_while{nil}.should == @enum.to_a
  end

  it "passes elements to the block until the first false" do
    a = []
    @enum.drop_while{|obj| (a << obj).size < 3}.should == [1, :go]
    a.should == [3, 2, 1]
  end

  it "will only go through what's needed" do
    enum = EnumerableSpecs::EachCounter.new(1,2,3,4)
    enum.drop_while { |x|
      break 42 if x == 3
      true
    }.should == 42
    enum.times_yielded.should == 3
  end

  it "doesn't return self when it could" do
    a = [1,2,3]
    a.drop_while{false}.should_not equal(a)
  end

  it "gathers whole arrays as elements when each yields multiple" do
    multi = EnumerableSpecs::YieldsMulti.new
    multi.drop_while {|e| e != [6, 7, 8, 9] }.should == [[6, 7, 8, 9]]
  end

  it_behaves_like :enumerable_enumeratorized_with_unknown_size, :drop_while
end