clojure - presence of a given set of keys in a clojure map - clojure

Question

There is a map like this
{:buyers [{:name "James" :city "Berlin"} {:name "Jane" :city "Milan"}]
:sellers [{:name "Dustin" :city "Turin" :age "21"} {:name "Mark" :city "Milan"}]}
and I need to check only for :sellers that all the keys :name, :city and :age are present and if one is missing drop
that map all together and have a new structure as below:
{:buyers [{:name "James" :city "Berlin"} {:name "Jane" :city "Milan"}]
:sellers [{:name "Dustin" :city "Turin" :age "21"}]}
I came across validateur and I am trying to use it like:
(:require [validateur.validation :as v])
(def my-map {:buyers [{:name "James" :city "Berlin"} {:name "Jane" :city "Milan"}]
:sellers [{:name "Dustin" :city "Turin" :age "21"} {:name "Dustin" :city "Milan" :age "" } {:city "Rome" :age "22"}]})
(defn valid-seller? [mp]
(let [v-set (v/validation-set
(v/presence-of #{:name :city :age}))]
(fmap vec (v-set mp))))
(map valid-seller? (:sellers my-map))
=> ({} {:age ["can't be blank"]} {:name ["can't be blank"]})
But I do not know how to update my map so missing keys or nil values be dropped

Answer 1

To make the code more readable, I created a new predicate, valid-seller?, and put validation there. You can use any of these versions:
Pure Clojure:
(defn valid-seller? [m]
(every? #(contains? m %) [:name :city :age]))
Spec:
[org.clojure/spec.alpha "0.3.218"], require [clojure.spec.alpha :as spec]
(defn valid-seller? [m]
(spec/valid? (spec/keys :req-un [::name ::city ::age]) m))
Malli (if you also want to test type of values):
[metosin/malli "0.8.9"], require [malli.core :as malli]
(defn valid-seller? [m]
(malli/validate [:map
[:name :string]
[:city :string]
[:age :string]] m))
Then I used this predicate:
(update {:buyers [{:name "James" :city "Berlin"} {:name "Jane" :city "Milan"}]
:sellers [{:name "Dustin" :city "Turin" :age "21"} {:name "Mark" :city "Milan"}]}
:sellers
#(filter valid-seller? %))
=>
{:buyers [{:name "James", :city "Berlin"} {:name "Jane", :city "Milan"}],
:sellers ({:name "Dustin", :city "Turin", :age "21"})}
After your answer, I think you should use Malli, as it also checks the type of values. You can use some? for any non-nil value:
(defn valid-seller? [m]
(malli/validate [:map
[:name some?]
[:city some?]
[:age some?]] m))

Answer 2

(let [data {:buyers [{:name "James" :city "Berlin"} {:name "Jane" :city "Milan"}]
:sellers [{:name "Dustin" :city "Turin" :age "21"} {:name "Mark" :city "Milan"}]}]
(update data :sellers #(filter (every-pred :name :city :age) %)))