feat(assert): adds new assert-like functionality to check malli schema

src/malli/core.cljc

@@ -1,5 +1,5 @@
 (ns malli.core
-  (:refer-clojure :exclude [eval type -deref deref -lookup -key])
+  (:refer-clojure :exclude [eval type -deref deref -lookup -key assert])
   #?(:cljs (:require-macros malli.core))
   (:require #?(:clj [clojure.walk :as walk])
             [clojure.core :as c]
@@ -2230,6 +2230,18 @@
   ([?schema value transformer respond raise] (coerce ?schema value transformer respond raise nil))
   ([?schema value transformer respond raise options] ((coercer ?schema transformer respond raise options) value)))
 
+(defmacro assert
+  "Assert that `value` validates against schema `?schema`, or throws ExceptionInfo.
+   The var clojure.core/*assert* determines whether assertion are checked."
+
+  ([?schema value]
+   `(assert ~?schema ~value nil))
+
+  ([?schema value options]
+   (if *assert*
+     `(coerce ~?schema ~value nil ~options)
+     value)))
+
 (defn entries
   "Returns `EntrySchema` children as a sequence of `clojure.lang/MapEntry`s
    where the values child schemas wrapped in `:malli.core/val` Schemas,

src/malli/dev/virhe.cljc

@@ -25,7 +25,9 @@
   (let [colors (:colors printer -dark-colors)
         color (get colors color (:error colors))]
     #?(:cljs [:span body]
-       :clj  [:span [:pass (str "\033[38;5;" color "m")] body [:pass "\u001B[0m"]])))
+       :clj (if color
+              [:span [:pass (str "\033[38;5;" color "m")] body [:pass "\u001B[0m"]]
+              [:span body]))))
 
 ;;
 ;; EDN

test/malli/assert_test.cljc

@@ -0,0 +1,29 @@
+(ns malli.assert-test
+  (:refer-clojure :exclude [assert])
+  (:require
+   [clojure.test :refer [deftest is]]
+   [malli.core :refer [assert]]))
+
+
+(set! *assert* true)
+
+(deftest assert-throws-test
+  (is (thrown? #?(:clj Exception, :cljs js/Error)
+               (assert :int "42" )))
+  (is (thrown? #?(:clj Exception, :cljs js/Error)
+               (assert int? "42" )))
+  (is (thrown? #?(:clj Exception, :cljs js/Error)
+               (assert string? 42)))
+  (is (thrown? #?(:clj Exception, :cljs js/Error)
+               (assert int? nil)))
+  (is (thrown? #?(:clj Exception, :cljs js/Error)
+               (assert [:map [:a int?]] {:a "42"})))
+  (is (thrown? #?(:clj Exception, :cljs js/Error)
+               (assert ::invalid-schema 42))))
+
+(deftest assert-checked-and-does-not-throw
+  (is (= 42 (assert :int 42 )))
+  (is (= 42 (assert int? 42 )))
+  (is (= "42" (assert string? "42")))
+  (is (= nil (assert any? nil)))
+  (is (= {:a 42} (assert [:map [:a int?]] {:a 42}))))