如何使用minitest测试Ruby捕获/抛出？

Question

I've got some pseudo code like this:

catch :my_error do
  first_method
  second_method
  third_method
end

def first_method
  if error_condition?
    throw :my_error
  end
end

I'm trying to use Minitest to test that the first method properly throws :my_error. My test looks like this:

assert_throws :my_error do
  some code in here that ensures error_condition? is true
end

When I run this test, Minitest fails the test with:

Minitest::Assertion: Expected :my_error to have been thrown

If I comment out the catch :my_error invocation, the test passes, but of course I need that code to be there in production. Not sure what the point of "assert_throws" is if it doesn't work with code that has catches in it.

Answer 1

assert_throws will assert that something has been thrown, so if it is catched by your code, you cannot assert that something has been thrown!

You can assert that a specific method throws, and then that another one that calls this one does not

Or if you change any data in the catch, you can test for this data