module MiniTest::Assertions

def self.diff
  @diff = if WINDOZE
            "diff.exe -u"
          else
            if system("gdiff", __FILE__, __FILE__)
              "gdiff -u" # solaris and kin suck
            elsif system("diff", __FILE__, __FILE__)
              "diff -u"
            else
              nil
            end
          end unless defined? @diff
  @diff
end

def self.diff= o
  @diff = o
end

def _assertions # :nodoc:
  @_assertions ||= 0
end

def _assertions= n # :nodoc:
  @_assertions = n
end

def assert test, msg = nil
  msg ||= "Failed assertion, no message given."
  self._assertions += 1
  unless test then
    msg = msg.call if Proc === msg
    raise MiniTest::Assertion, msg
  end
  true
end

def assert_block msg = nil
  warn "NOTE: MiniTest::Unit::TestCase#assert_block is deprecated, use assert. It will be removed on 2013-01-01. Called from #{caller.first}"
  msg = message(msg) { "Expected block to return true value" }
  assert yield, msg
end

def assert_empty obj, msg = nil
  msg = message(msg) { "Expected #{mu_pp(obj)} to be empty" }
  assert_respond_to obj, :empty?
  assert obj.empty?, msg
end

def assert_equal exp, act, msg = nil
  msg = message(msg, "") { diff exp, act }
  assert(exp == act, msg)
end

def assert_in_delta exp, act, delta = 0.001, msg = nil
  n = (exp - act).abs
  msg = message(msg) { "Expected |#{exp} - #{act}| (#{n}) to be < #{delta}"}
  assert delta >= n, msg
end

def assert_in_epsilon a, b, epsilon = 0.001, msg = nil
  assert_in_delta a, b, [a.abs, b.abs].min * epsilon, msg
end

def assert_includes collection, obj, msg = nil
  msg = message(msg) {
    "Expected #{mu_pp(collection)} to include #{mu_pp(obj)}"
  }
  assert_respond_to collection, :include?
  assert collection.include?(obj), msg
end

def assert_instance_of cls, obj, msg = nil
  msg = message(msg) {
    "Expected #{mu_pp(obj)} to be an instance of #{cls}, not #{obj.class}"
  }
  assert obj.instance_of?(cls), msg
end

def assert_kind_of cls, obj, msg = nil # TODO: merge with instance_of
  msg = message(msg) {
    "Expected #{mu_pp(obj)} to be a kind of #{cls}, not #{obj.class}" }
  assert obj.kind_of?(cls), msg
end

def assert_match matcher, obj, msg = nil
  msg = message(msg) { "Expected #{mu_pp matcher} to match #{mu_pp obj}" }
  assert_respond_to matcher, :"=~"
  matcher = Regexp.new Regexp.escape matcher if String === matcher
  assert matcher =~ obj, msg
end

def assert_nil obj, msg = nil
  msg = message(msg) { "Expected #{mu_pp(obj)} to be nil" }
  assert obj.nil?, msg
end

def assert_operator o1, op, o2 = UNDEFINED, msg = nil
  return assert_predicate o1, op, msg if UNDEFINED == o2
  msg = message(msg) { "Expected #{mu_pp(o1)} to be #{op} #{mu_pp(o2)}" }
  assert o1.__send__(op, o2), msg
end

def assert_output stdout = nil, stderr = nil
  out, err = capture_io do
    yield
  end
  y = assert_equal stderr, err, "In stderr" if stderr
  x = assert_equal stdout, out, "In stdout" if stdout
  (!stdout || x) && (!stderr || y)
end

def assert_predicate o1, op, msg = nil
  msg = message(msg) { "Expected #{mu_pp(o1)} to be #{op}" }
  assert o1.__send__(op), msg
end

def assert_raises *exp
  msg = "#{exp.pop}.\n" if String === exp.last
  should_raise = false
  begin
    yield
    should_raise = true
  rescue MiniTest::Skip => e
    details = "#{msg}#{mu_pp(exp)} exception expected, not"
    if exp.include? MiniTest::Skip then
      return e
    else
      raise e
    end
  rescue Exception => e
    details = "#{msg}#{mu_pp(exp)} exception expected, not"
    assert(exp.any? { |ex|
             ex.instance_of?(Module) ? e.kind_of?(ex) : ex == e.class
           }, exception_details(e, details))
    return e
  end
  exp = exp.first if exp.size == 1
  flunk "#{msg}#{mu_pp(exp)} expected but nothing was raised." if
    should_raise
end

def assert_respond_to obj, meth, msg = nil
  msg = message(msg) {
    "Expected #{mu_pp(obj)} (#{obj.class}) to respond to ##{meth}"
  }
  assert obj.respond_to?(meth), msg
end

def assert_same exp, act, msg = nil
  msg = message(msg) {
    data = [mu_pp(act), act.object_id, mu_pp(exp), exp.object_id]
    "Expected %s (oid=%d) to be the same as %s (oid=%d)" % data
  }
  assert exp.equal?(act), msg
end

def assert_send send_ary, m = nil
  recv, msg, *args = send_ary
  m = message(m) {
    "Expected #{mu_pp(recv)}.#{msg}(*#{mu_pp(args)}) to return true" }
  assert recv.__send__(msg, *args), m
end

def assert_silent
  assert_output "", "" do
    yield
  end
end

def assert_throws sym, msg = nil
  default = "Expected #{mu_pp(sym)} to have been thrown"
  caught = true
  catch(sym) do
    begin
      yield
    rescue ArgumentError => e     # 1.9 exception
      default += ", not #{e.message.split(/ /).last}"
    rescue NameError => e         # 1.8 exception
      default += ", not #{e.name.inspect}"
    end
    caught = false
  end
  assert caught, message(msg) { default }
end

def capture_io
  require 'stringio'
  orig_stdout, orig_stderr         = $stdout, $stderr
  captured_stdout, captured_stderr = StringIO.new, StringIO.new
  $stdout, $stderr                 = captured_stdout, captured_stderr
  yield
  return captured_stdout.string, captured_stderr.string
ensure
  $stdout = orig_stdout
  $stderr = orig_stderr
end

def diff exp, act
  require "tempfile"
  expect = mu_pp_for_diff exp
  butwas = mu_pp_for_diff act
  result = nil
  need_to_diff =
    MiniTest::Assertions.diff &&
    (expect.include?("\n")    ||
     butwas.include?("\n")    ||
     expect.size > 30         ||
     butwas.size > 30         ||
     expect == butwas)
  return "Expected: #{mu_pp exp}\n  Actual: #{mu_pp act}" unless
    need_to_diff
  Tempfile.open("expect") do |a|
    a.puts expect
    a.flush
    Tempfile.open("butwas") do |b|
      b.puts butwas
      b.flush
      result = `#{MiniTest::Assertions.diff} #{a.path} #{b.path}`
      result.sub!(/^\-\-\- .+/, "--- expected")
      result.sub!(/^\+\+\+ .+/, "+++ actual")
      if result.empty? then
        klass = exp.class
        result = [
                  "No visible difference.",
                  "You should look at your implementation of #{klass}#==.",
                  expect
                 ].join "\n"
      end
    end
  end
  result
end

def exception_details e, msg
  [
   "#{msg}",
   "Class: <#{e.class}>",
   "Message: <#{e.message.inspect}>",
   "---Backtrace---",
   "#{MiniTest::filter_backtrace(e.backtrace).join("\n")}",
   "---------------",
  ].join "\n"
end

def flunk msg = nil
  msg ||= "Epic Fail!"
  assert false, msg
end

def message msg = nil, ending = ".", &default
  proc {
    custom_message = "#{msg}.\n" unless msg.nil? or msg.to_s.empty?
    "#{custom_message}#{default.call}#{ending}"
  }
end

def mu_pp obj
  s = obj.inspect
  s = s.encode Encoding.default_external if defined? Encoding
  s
end

def mu_pp_for_diff obj # TODO: possibly rename
  mu_pp(obj).gsub(/\\n/, "\n").gsub(/0x[a-f0-9]+/m, '0xXXXXXX')
end

def pass msg = nil
  assert true
end

def refute test, msg = nil
  msg ||= "Failed refutation, no message given"
  not assert(! test, msg)
end

def refute_empty obj, msg = nil
  msg = message(msg) { "Expected #{mu_pp(obj)} to not be empty" }
  assert_respond_to obj, :empty?
  refute obj.empty?, msg
end

def refute_equal exp, act, msg = nil
  msg = message(msg) {
    "Expected #{mu_pp(act)} to not be equal to #{mu_pp(exp)}"
  }
  refute exp == act, msg
end

def refute_in_delta exp, act, delta = 0.001, msg = nil
  n = (exp - act).abs
  msg = message(msg) {
    "Expected |#{exp} - #{act}| (#{n}) to not be < #{delta}"
  }
  refute delta > n, msg
end

def refute_in_epsilon a, b, epsilon = 0.001, msg = nil
  refute_in_delta a, b, a * epsilon, msg
end

def refute_includes collection, obj, msg = nil
  msg = message(msg) {
    "Expected #{mu_pp(collection)} to not include #{mu_pp(obj)}"
  }
  assert_respond_to collection, :include?
  refute collection.include?(obj), msg
end

def refute_instance_of cls, obj, msg = nil
  msg = message(msg) {
    "Expected #{mu_pp(obj)} to not be an instance of #{cls}"
  }
  refute obj.instance_of?(cls), msg
end

def refute_kind_of cls, obj, msg = nil # TODO: merge with instance_of
  msg = message(msg) { "Expected #{mu_pp(obj)} to not be a kind of #{cls}" }
  refute obj.kind_of?(cls), msg
end

def refute_match matcher, obj, msg = nil
  msg = message(msg) {"Expected #{mu_pp matcher} to not match #{mu_pp obj}"}
  assert_respond_to matcher, :"=~"
  matcher = Regexp.new Regexp.escape matcher if String === matcher
  refute matcher =~ obj, msg
end

def refute_nil obj, msg = nil
  msg = message(msg) { "Expected #{mu_pp(obj)} to not be nil" }
  refute obj.nil?, msg
end

def refute_operator o1, op, o2 = UNDEFINED, msg = nil
  return refute_predicate o1, op, msg if UNDEFINED == o2
  msg = message(msg) { "Expected #{mu_pp(o1)} to not be #{op} #{mu_pp(o2)}"}
  refute o1.__send__(op, o2), msg
end

def refute_predicate o1, op, msg = nil
  msg = message(msg) { "Expected #{mu_pp(o1)} to not be #{op}" }
  refute o1.__send__(op), msg
end

def refute_respond_to obj, meth, msg = nil
  msg = message(msg) { "Expected #{mu_pp(obj)} to not respond to #{meth}" }
  refute obj.respond_to?(meth), msg
end

def refute_same exp, act, msg = nil
  msg = message(msg) {
    data = [mu_pp(act), act.object_id, mu_pp(exp), exp.object_id]
    "Expected %s (oid=%d) to not be the same as %s (oid=%d)" % data
  }
  refute exp.equal?(act), msg
end

def skip msg = nil, bt = caller
  msg ||= "Skipped, no message given"
  raise MiniTest::Skip, msg, bt
end