Re: How to assert "throw" by ERT?

[Dmitry Gutov <dgutov@yandex.ru>]

Oleksandr Gavenko <gavenkoa@gmail.com> writes:

> ERT is Emacs Lisp Regression Testing and ERT packed in GNU Emacs.
>
> I want to check that my function throw on some input data:
>
>   (defun foo (arg) (unless arg (throw :invalid-arg nil)))
>
> I write:
>
>   (ert-deftest foo-fail-test ()
>     (should-error (foo nil) :type :invalid-arg)
>     )
>
> but seems this is wrong usege or 'should-error'.

In Emacs Lisp, `throw' and `catch' are a control flow mechanism, not
exception handling primitives. But your function will indeed error,
because it can't find a matching `catch' block. This test passes:

  (ert-deftest foo-fail-test ()
    (should-error (foo nil) :type 'no-catch))