I could use some guidance on using clojure.spec to validate input arguments to a function. Here’s some context: • I am debating instrumenting with fdef vs. using :pre and :post conditions. • The function is internal to the app and the argument values are completely under the control of the programmer (i.e. there is no validation of external data going on). I was initially leaning toward instrumenting with fdef because I see this as a check for program correctness rather input validation. It should be safe to turn this check off in production with no change in behavior. But I want the instrumentation to be turned on by default during development and turned off by default in production. I can imagine ways to achieve that, but the fact that I couldn’t find any mention of a typical pattern for doing that (e.g. my understanding is that assert is set up to be easily enabled/disabled in a blanket manner) made me think I might be missing something.

Are you talking about clojure.core/assert or s/assert? Seems like the latter would be good here

Hello. Where i have several defined and registered predicates, can i compose them in this state?

;; contrived example
(s/def ::string-starts-with-an-a? (s/and string? #(string/starts-with? % "a")))
(s/def ::not-an-apple? #(not= "apple" %))
(s/def ::starts-with-an-a-but-not-an-apple? (s/and ::string-starts-with-an-a? ::not-an-apple?))

predicate composing after registration

disregard the above. my forms had not been evaluated, thus the error received was entirely my doing