require 'test/unit'
require 'thread'

class TestBacktrace < Test::Unit::TestCase
  def test_exception
    bt = Fiber.new{
      begin
        raise
      rescue => e
        e.backtrace
      end
    }.resume
    assert_equal(1, bt.size)
    assert_match(/.+:\d+:.+/, bt[0])
  end

  def test_caller_lev
    cs = []
    Fiber.new{
      Proc.new{
        cs << caller(0)
        cs << caller(1)
        cs << caller(2)
        cs << caller(3)
        cs << caller(4)
        cs << caller(5)
      }.call
    }.resume
    assert_equal(3, cs[0].size)
    assert_equal(2, cs[1].size)
    assert_equal(1, cs[2].size)
    assert_equal(0, cs[3].size)
    assert_equal(nil, cs[4])

    #
    max = 7
    rec = lambda{|n|
      if n > 0
        1.times{
          rec[n-1]
        }
      else
        (max*3).times{|i|
          total_size = caller(0).size
          c = caller(i)
          if c
            assert_equal(total_size - i, caller(i).size, "[ruby-dev:45673]")
          end
        }
      end
    }
    bt = Fiber.new{
      rec[max]
    }.resume
  end

  def test_caller_lev_and_n
    m = 10
    rec = lambda{|n|
      if n < 0
        (m*6).times{|lev|
          (m*6).times{|n|
            t = caller(0).size
            r = caller(lev, n)
            r = r.size if r.respond_to? :size

            # STDERR.puts [t, lev, n, r].inspect
            if n == 0
              assert_equal(0, r, [t, lev, n, r].inspect)
            elsif t < lev
              assert_equal(nil, r, [t, lev, n, r].inspect)
            else
              if t - lev > n
                assert_equal(n, r, [t, lev, n, r].inspect)
              else
                assert_equal(t - lev, r, [t, lev, n, r].inspect)
              end
            end
          }
        }
      else
        rec[n-1]
      end
    }
    rec[m]
  end

  def test_caller_with_nil_length
    assert_equal caller(0), caller(0, nil)
  end

  def test_caller_locations
    cs = caller(0); locs = caller_locations(0).map{|loc|
      loc.to_s
    }
    assert_equal(cs, locs)
  end

  def test_caller_locations_with_range
    cs = caller(0,2); locs = caller_locations(0..1).map { |loc|
      loc.to_s
    }
    assert_equal(cs, locs)
  end

  def test_caller_locations_to_s_inspect
    cs = caller(0); locs = caller_locations(0)
    cs.zip(locs){|str, loc|
      assert_equal(str, loc.to_s)
      assert_equal(str.inspect, loc.inspect)
    }
  end

  def th_rec q, n=10
    if n > 1
      th_rec q, n-1
    else
      q.pop
    end
  end

  def test_thread_backtrace
    begin
      q = Queue.new
      th = Thread.new{
        th_rec q
      }
      sleep 0.5
      th_backtrace = th.backtrace
      th_locations = th.backtrace_locations

      assert_equal(10, th_backtrace.count{|e| e =~ /th_rec/})
      assert_equal(th_backtrace, th_locations.map{|e| e.to_s})
      assert_equal(th_backtrace, th.backtrace(0))
      assert_equal(th_locations.map{|e| e.to_s},
                   th.backtrace_locations(0).map{|e| e.to_s})
      th_backtrace.size.times{|n|
        assert_equal(n, th.backtrace(0, n).size)
        assert_equal(n, th.backtrace_locations(0, n).size)
      }
      n = th_backtrace.size
      assert_equal(n, th.backtrace(0, n + 1).size)
      assert_equal(n, th.backtrace_locations(0, n + 1).size)
    ensure
      q << true
    end
  end

  def test_thread_backtrace_locations_with_range
    begin
      q = Queue.new
      th = Thread.new{
        th_rec q
      }
      sleep 0.5
      bt = th.backtrace(0,2)
      locs = th.backtrace_locations(0..1).map { |loc|
        loc.to_s
      }
      assert_equal(bt, locs)
    ensure
      q << true
    end
  end

  def test_core_backtrace_alias
    obj = BasicObject.new
    e = assert_raise(NameError) do
      class << obj
        alias foo bar
      end
    end
    /`(.*)'\z/.match e.backtrace[0]
    assert_not_match(/\Acore#/, $1)
  end

  def test_core_backtrace_undef
    obj = BasicObject.new
    e = assert_raise(NameError) do
      class << obj
        undef foo
      end
    end
    /`(.*)'\z/.match e.backtrace[0]
    assert_not_match(/\Acore#/, $1)
  end
end
