如何在Ruby中將塊傳遞給assert_raise？

Question

使用Ruby-1.9.3 ...

我讀過一些規範的博客文章對塊&特效的主題，但我不明白爲什麼這兩種情況是不同的：

module TestHelpers 
    def bad_arg_helper(&scenario) 

    # this works fine, test passes (without the next line) 
    assert_raise ArgumentError, "wrong type of arguments, pass Fixnum or Range parameters", { Myclass.myfunc "bad" } 

    # even though the exception is correctly raised in myfunc, this assert does not see it and the test fails 
    assert_raise ArgumentError, "wrong type of arguments, pass Fixnum or Range parameters", scenario.call 
    end 
end 

class TestClass < Test::Unit::TestCase 
    include TestHelpers 

    def test_bad_args 
    bad_arg_helper { Myclass.myfunc "bad" } 
    end 
end 

如何將一個塊傳遞給另一個模塊中的測試助手？

Answer 1

請參閱代碼中的三個變種：

require 'test/unit' 
class Myclass 
    def self.myfunc(par) 
    raise ArgumentError unless par.is_a?(Fixnum) 
    end 
end 

module TestHelpers 
    def bad_arg_helper(&scenario) 

    # this works fine, test passes (without the next line) 
    assert_raise(ArgumentError, "wrong type of arguments, pass Fixnum or Range parameters") { Myclass.myfunc "bad" } 

    # even though the exception is correctly raised in myfunc, this assert does not see it and the test fails 
    assert_raise(ArgumentError, "wrong type of arguments, pass Fixnum or Range parameters", &scenario) 
    assert_raise(ArgumentError, "wrong type of arguments, pass Fixnum or Range parameters") { yield } 
    assert_raise(ArgumentError, "wrong type of arguments, pass Fixnum or Range parameters") { scenario.call } 
    end 
end 

class TestClass < Test::Unit::TestCase 
    include TestHelpers 

    def test_bad_args 
    bad_arg_helper { Myclass.myfunc "bad" } 
    end 
end