require 'test/unit' class TestArity < Test::Unit::TestCase def err_mess(method_proc = nil, argc = 0) args = (1..argc).to_a err = assert_raise(ArgumentError) do case method_proc when nil yield when Symbol method(method_proc).call(*args) else method_proc.call(*args) end end s = err.to_s assert s =~ /wrong number of arguments \((.*)\)/, "Unexpected ArgumentError's message: #{s}" $1 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 "1 for 0", err_mess(:a, 1) assert_equal "10 for 7..9", err_mess(:b, 10) assert_equal "2 for 3+", err_mess(:c, 2) assert_equal "2 for 1", err_mess(:d, 2) assert_equal "0 for 1", err_mess(:d, 0) assert_equal "2 for 1", err_mess(:e, 2) assert_equal "0 for 1", err_mess(:e, 0) assert_equal "1 for 2+", err_mess(:f, 1) end def test_proc_err_mess assert_equal "0 for 1..2", err_mess(->(b, c=42){}, 0) assert_equal "1 for 2+", err_mess(->(a, b, c=42, *d){}, 1) assert_equal "3 for 4+", err_mess(->(a, b, *c, d, e){}, 3) assert_equal "3 for 1..2", err_mess(->(b, c=42){}, 3) assert_equal "1 for 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 "3 for 1..2", err_mess{ SignalException.new(1, "", nil) } assert_equal "1 for 0", err_mess{ Hash.new(1){} } assert_equal "3 for 1..2", err_mess{ Module.send :define_method, 1, 2, 3 } assert_equal "1 for 2", err_mess{ "".sub!(//) } assert_equal "0 for 1..2", err_mess{ "".sub!{} } assert_equal "0 for 1+", err_mess{ exec } assert_equal "0 for 1+", err_mess{ Struct.new } end end