require 'test/unit' class TestArity < Test::Unit::TestCase def err_mess(method_proc = nil, argc = 0) args = (1..argc).to_a assert_raise_with_message(ArgumentError, /wrong number of arguments \(.*\b(\d+)\b.* (\d\S*?)\)/) do case method_proc when nil yield when Symbol method(method_proc).call(*args) else method_proc.call(*args) end end [$1, $2] end def a end def b(a, b, c, d=1, e=2, f, g, h, i, &block) end def c(a, b, c, d=1, e=2, *rest) end def d(a, b: 42) end def e(a, b:42, **c) end def f(a, b, c=1, *rest, d: 3) end def test_method_err_mess assert_equal %w[1 0], err_mess(:a, 1) assert_equal %w[10 7..9], err_mess(:b, 10) assert_equal %w[2 3+], err_mess(:c, 2) assert_equal %w[2 1], err_mess(:d, 2) assert_equal %w[0 1], err_mess(:d, 0) assert_equal %w[2 1], err_mess(:e, 2) assert_equal %w[0 1], err_mess(:e, 0) assert_equal %w[1 2+], err_mess(:f, 1) end def test_proc_err_mess assert_equal %w[0 1..2], err_mess(->(b, c=42){}, 0) assert_equal %w[1 2+], err_mess(->(a, b, c=42, *d){}, 1) assert_equal %w[3 4+], err_mess(->(a, b, *c, d, e){}, 3) assert_equal %w[3 1..2], err_mess(->(b, c=42){}, 3) assert_equal %w[1 0], err_mess(->(&block){}, 1) # Double checking: p = Proc.new{|b, c=42| :ok} assert_equal :ok, p.call(1, 2, 3) assert_equal :ok, p.call end def test_message_change_issue_6085 assert_equal %w[3 1..2], err_mess{ SignalException.new(1, "", nil) } assert_equal %w[1 0], err_mess{ Hash.new(1){} } assert_equal %w[3 1..2], err_mess{ Module.send :define_method, 1, 2, 3 } assert_equal %w[1 2], err_mess{ "".sub!(//) } assert_equal %w[0 1..2], err_mess{ "".sub!{} } assert_equal %w[0 1+], err_mess{ exec } assert_equal %w[0 1+], err_mess{ Struct.new } end end