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

describe "Bignum#[]" do
  before(:each) do
    @bignum = bignum_value(4996)
  end

  it "returns the nth bit in the binary representation of self" do
    @bignum[2].should == 1
    @bignum[9.2].should == 1
    @bignum[21].should == 0
    @bignum[0xffffffff].should == 0
    @bignum[-0xffffffff].should == 0
  end

  it "tries to convert the given argument to an Integer using #to_int" do
    @bignum[1.3].should == @bignum[1]

    (obj = mock('2')).should_receive(:to_int).at_least(1).and_return(2)
    @bignum[obj].should == 1
  end

  it "raises a TypeError when the given argument can't be converted to Integer" do
    obj = mock('asdf')
    lambda { @bignum[obj] }.should raise_error(TypeError)

    obj.should_receive(:to_int).and_return("asdf")
    lambda { @bignum[obj] }.should raise_error(TypeError)
  end
end
