The ::invalid keyword occurs 67 times in the spec repo:

$ ./grasp ~/git/spec.alpha/src -w -e "(fn [k] (= :clojure.spec.alpha/invalid (unwrap k)))" | wc -l
      67

Hi please advice, how I can write a spec for :fileds

(s/explain-data ::fields [{:name "aaa" :type "bbbb"} {:name 1 :type "cccc"}])

@kirill.salykin The uniqueness of the name is a property of the collection, not of one item

user=> (s/def ::unique-names (fn [xs] (= (map :name xs) (distinct (map :name xs)))))
:user/unique-names
user=> (s/explain ::unique-names [{:name :foo} {:name :bar}])
Success!
nil
user=> (s/explain ::unique-names [{:name :foo} {:name :foo}])
[{:name :foo} {:name :foo}] - failed: (fn [xs] (= (map :name xs) (distinct (map :name xs)))) spec: :user/unique-names

I understand and agree thought there is a dark magic to get indecies of non-unique elements, but apparently no thanks for the answer

There might be, but I don't know if it's pretty

maybe there is a way shape spec output in a way as it reports per failed element (eg with s/problems, path (`:in []`) and predicate?)

@kirill.salykin Maybe something like this:

user=> (s/def ::unique-names (s/and #(group-by :name %) (s/every-kv any? #(= 1 (count %)))))
:user/unique-names
user=> (s/explain ::unique-names [{:name :foo} {:name :foo}])
Execution error (UnsupportedOperationException) at user/fn (REPL:1).
nth not supported on this type: PersistentArrayMap

@kirill.salykin Ah, I needed s/conformer:

user=> (s/def ::unique-names (s/and (s/conformer #(group-by :name %)) (s/every-kv any? #(= 1 (count %)))))
:user/unique-names
user=> (s/explain ::unique-names [{:name :foo} {:name :foo}])
[{:name :foo} {:name :foo}] - failed: (= 1 (count %)) in: [:foo 1] at: [1] spec: :user/unique-names

you are magician! thank you so much!

I've made binary versions of grasp available in the #grasp channel now. Clojure spec on the command line, yeah :)