adds #hawk/malli as a reader for =?

deps.edn

@@ -8,6 +8,7 @@
   methodical/methodical       {:mvn/version "0.15.1"}
   pjstadig/humane-test-output {:mvn/version "0.11.0"}
   prismatic/schema            {:mvn/version "1.4.1"}
+  metosin/malli               {:mvn/version "0.13.0"}
   org.clojure/algo.generic    {:mvn/version "0.1.3"}
   org.clojure/java.classpath  {:mvn/version "1.0.0"}
   org.clojure/tools.namespace {:mvn/version "1.3.0"}}

resources/data_readers.clj

@@ -1,3 +1,4 @@
 {hawk/exactly mb.hawk.assert-exprs.approximately-equal/read-exactly
  hawk/schema  mb.hawk.assert-exprs.approximately-equal/read-schema
+ hawk/malli   mb.hawk.assert-exprs.approximately-equal/read-malli
  hawk/approx  mb.hawk.assert-exprs.approximately-equal/read-approx}

src/mb/hawk/assert_exprs/approximately_equal.clj

@@ -3,6 +3,8 @@
   (:require
    [clojure.algo.generic.math-functions :as algo.generic.math]
    [clojure.pprint :as pprint]
+   [malli.core :as m]
+   [malli.error :as me]
    [methodical.core :as methodical]
    [schema.core :as s]))
 
@@ -155,6 +157,31 @@
   [^Schema this actual]
   (s/check (.schema this) actual))
 
+(deftype Malli [schema])
+
+(defn read-malli
+  "Data reader for `#hawk/malli`."
+  [schema-form]
+  (->Malli (eval schema-form)))
+
+(defmethod print-dup Malli
+  [^Malli this ^java.io.Writer writer]
+  (.write writer (format "#hawk/malli %s" (pr-str (.schema this)))))
+
+(defmethod print-method Malli
+  [this writer]
+  ((get-method print-dup Malli) this writer))
+
+(defmethod pprint/simple-dispatch Malli
+  [^Malli this]
+  (pprint/pprint-logical-block
+   :prefix "#hawk/malli " :suffix nil
+   (pprint/write-out (.schema this))))
+
+(methodical/defmethod =?-diff [Malli :default]
+  [^Malli this actual]
+  (me/humanize (m/explain (.schema this) actual)))
+
 (deftype Approx [expected epsilon])
 
 (defn read-approx

test/mb/hawk/assert_exprs/approximately_equal_test.clj

@@ -119,6 +119,26 @@
                (read-string (pr-str (approximately-equal/=?-diff {:a 1, :b #hawk/schema {:c s/Int}}
                                                                  {:a 1, :b {:c 2.0}})))))))))
 
+(deftest ^:parallel malli-test
+  (testing "#hawk/malli"
+    (is (=? #hawk/malli [:map [:a :int]]
+            {:a 1}))
+    (testing "Nested inside a collection"
+      (is (=? {:a 1, :b #hawk/malli [:map-of :keyword :int]}
+              {:a 1, :b {}}))
+      (is (=? {:a 1, :b #hawk/malli [:map-of :keyword :int]}
+              {:a 1, :b {:c 2}}))
+      (is (=? {:a 1, :b #hawk/malli [:map-of :keyword :int]}
+              {:a 1, :b {:c 2, :d 3}})))
+    (testing "failures"
+      ;; serialize these to strings and read them back out because Schema actually returns weird classes like
+      ;; ValidationError or whatever that aren't equal to their printed output
+      (is (= '{:a ["should be an integer"]}
+             (read-string (pr-str (approximately-equal/=?-diff #hawk/malli [:map [:a :int]] {:a 1.0})))))
+      (testing "Inside a collection"
+        (is (= '{:b {:c ["should be an integer"]}}
+               (read-string (pr-str (approximately-equal/=?-diff {:a 1, :b #hawk/malli [:map [:c :int]]}
+                                                                 {:a 1, :b {:c 2.0}})))))))))
 (deftest ^:parallel approx-test
   (testing "#hawk/approx"
     (is (=? #hawk/approx [1.5 0.1]