asserting a structure produces an error

Stream: new members

[Julian Berman]

Is there a testing helper or something that I can use to assert that the second example below produces an error?

import tactic

structure foo :=
(value : ℕ)
(istwelve : value = 12 . tactic.exact_dec_trivial)

example : foo := { foo . value := 12 }

-- assertBlowsUp
example : foo := { foo . value := 13 }

[Anne Baanen]

Maybe docs#tactic.success_if_fail helps?

[Julian Berman]

Thanks! Appreciate the pointer, will see if I can use that.