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

describe "Kernel#freeze" do
  it "prevents self from being further modified" do
    o = mock('o')
    o.frozen?.should be_false
    o.freeze
    o.frozen?.should be_true
  end

  it "returns self" do
    o = Object.new
    o.freeze.should equal(o)
  end

  # 1.9 allows immediates to be frozen #1747. Test in a separate process so
  # as to avoid polluting the spec process with frozen immediates.
  it "freezes immediate values" do
    ruby_exe("print [nil, true, false, 1, :sym].map {|o| o.freeze; o.frozen? }").should ==
      "[true, true, true, true, true]"
  end

  it "causes mutative calls to raise RuntimeError" do
    o = Class.new do
      def mutate; @foo = 1; end
    end.new
    o.freeze
    lambda {o.mutate}.should raise_error(RuntimeError)
  end

  it "causes instance_variable_set to raise RuntimeError" do
    o = Object.new
    o.freeze
    lambda {o.instance_variable_set(:@foo, 1)}.should raise_error(RuntimeError)
  end
end
