require "spec_helper"

describe "garbage collection" do

  describe Uri do
    it "is garbage collected when destroyed" do
      Uri.new("http://example.com/subject")
      expect(ObjectSpace.each_object(Uri).count).to eq(1)
      GC.start
      expect(ObjectSpace.each_object(Uri).count).to eq(0)
    end 
  end

  describe Node do
    it "is garbage collected when destroyed" do
      Node.new(test_statement[:subject])
      expect(ObjectSpace.each_object(Node).count).to eq(1)
      GC.start
      expect(ObjectSpace.each_object(Node).count).to eq(0)
    end
  end

  describe Statement do
    it "is garbage collected when destroyed" do
      Statement.new(test_statement)
      expect(ObjectSpace.each_object(Statement).count).to eq(1)
      GC.start
      expect(ObjectSpace.each_object(Statement).count).to eq(0)
    end
  end

  describe Model do
    it "is garbage collected when destroyed" do
      Model.new
      expect(ObjectSpace.each_object(Model).count).to eq(1)
      GC.start
      expect(ObjectSpace.each_object(Model).count).to eq(0)
    end
  end

  describe Query::Results do
    it "is garbage collected when destroyed" do
      model = Model.new
      model.statements.add(Statement.new(test_statement))
      model.query("select * {?s ?p ?o}")
      expect(ObjectSpace.each_object(Query::Results).count).to eq(1)
      GC.start
      expect(ObjectSpace.each_object(Query::Results).count).to eq(0)
    end
  end

  it "collects all objects after using Model" do
    model = Model.new
    expect(ObjectSpace.each_object(Model).count).to eq(1)

    model.statements.add(Statement.new(test_statement))
    expect(ObjectSpace.each_object(Node).count).to eq(3)
    expect(ObjectSpace.each_object(Statement).count).to eq(1)

    model.query("select * {?s ?p ?o}")
    expect(ObjectSpace.each_object(Node).count).to eq(6)
    expect(ObjectSpace.each_object(Query::Results).count).to eq(1)

    # allow model to be garbage collected
    model = nil

    GC.start
    expect(ObjectSpace.each_object(Model).count).to eq(0)
    expect(ObjectSpace.each_object(Statement).count).to eq(0)
    expect(ObjectSpace.each_object(Query::Results).count).to eq(0)
  end

  private

  def test_statement
    {
      :subject => URI.parse("http://example.com/subject"),
      :predicate => URI.parse("http://example.com/predicate"),
      :object => URI.parse("object!")
    }
  end
end