would clojure.test benefit from `(defmethod assert-expr thrown-with-data? ...)`

Question

I think several times I have done something similar to

(is (= some-map (try (func ...) (catch Exception e (ex-data e)))

Not sure if this had been asked before but would there be any interest in some form of

(defmethod assert-expr 'thrown-with-data? [x form]

that would check the data map of an exception?

One complication is that strings have any easy vehicle for partial matching: the regex. Maps have no ubiquitous matcher like this, leading to no obvious input. Options could be a single arg function that would receive the map and return true or false similar to the regex. Or maybe just allow for a value to compare against? Perhaps a spec?

Obviously lots of design choices here and not sure if that means leave it to individual users or if there was room or interest in clojure.test.

Comments

An example of library that gives you this functionality is matcher-combinators:
```
(deftest exception-matching
  (is (thrown-match? clojure.lang.ExceptionInfo
                     {:foo 1}
                     (throw (ex-info "Boom!" {:foo 1 :bar 2})))))
```

https://github.com/nubank/matcher-combinators#clojuretest

Answer 1

Definitely interested if there’s something that makes sense. Would be interested if people have created things like this already if there’s any experience.