require_relative '../../spec_helper'

describe "Fiber.new" do
  it "creates a fiber from the given block" do
    fiber = Fiber.new {}
    fiber.resume
    fiber.should be_an_instance_of(Fiber)
  end

  it "creates a fiber from a subclass" do
    class MyFiber < Fiber
    end
    fiber = MyFiber.new {}
    fiber.resume
    fiber.should be_an_instance_of(MyFiber)
  end

  it "raises an ArgumentError if called without a block" do
    lambda { Fiber.new }.should raise_error(ArgumentError)
  end

  it "does not invoke the block" do
    invoked = false
    fiber = Fiber.new { invoked = true }
    invoked.should be_false
    fiber.resume
  end

  it "closes over lexical environments" do
    o = Object.new
    def o.f
      a = 1
      f = Fiber.new { a = 2 }
      f.resume
      a
    end
    o.f.should == 2
  end
end