Forbid nilable primitive type hints

nedap · May 21, 2019 · c3162b8 · c3162b8
1 parent f515ecf
commit c3162b8
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Showing 2 changed files with 28 additions and 7 deletions.
diff --git a/src/nedap/utils/spec/impl/parsing.cljc b/src/nedap/utils/spec/impl/parsing.cljc
@@ -172,7 +172,12 @@
        :type-annotation (cond
                           (primitive? inferred-class clj?) inferred-class
                           clj?                             (#?(:clj resolve :cljs fail) inferred-class)
-                          true                             inferred-class)})))
+                          true                             inferred-class)
+
+       :was-primitive?  (primitive? s clj?)})))
+
+(def forbidden-primitives-message
+  "Primitive type hints aren't nilable. That would emit code that would fail opaquely.")
 
 (defn extract-specs-from-metadata [metadata-map clj?]
   {:post [(check! #{0 1}                                       (->> metadata-map
@@ -213,12 +218,15 @@
                     {:spec            v
                      :type-annotation nil}))))
          (filter some?)
-         (map (fn [{:keys [spec] :as result}]
-                (cond-> result
-                  nilable? (assoc :spec (list (if clj?
-                                                'clojure.spec.alpha/nilable
-                                                'cljs.spec.alpha/nilable)
-                                              spec))))))))
+         (map (fn [{:keys [spec was-primitive?] :as result}]
+                (cond
+                  nilable? (do
+                             (assert (not was-primitive?) forbidden-primitives-message)
+                             (assoc result :spec (list (if clj?
+                                                         'clojure.spec.alpha/nilable
+                                                         'cljs.spec.alpha/nilable)
+                                                       spec)))
+                  true     result))))))
 
 (defn ^{:author  "Rich Hickey"
         :license "Eclipse Public License 1.0"

diff --git a/test/unit/nedap/utils/speced/defn.cljc b/test/unit/nedap/utils/speced/defn.cljc
@@ -9,6 +9,7 @@
    [clojure.string :as string]
    #?(:clj [clojure.test :refer [deftest testing are is use-fixtures]] :cljs [cljs.test :refer-macros [deftest testing is are] :refer [use-fixtures]])
    [nedap.utils.speced :as sut]
+   [nedap.utils.spec.impl.parsing :as impl.parsing]
    [unit.nedap.test-helpers :refer [every-and-at-least-one?]])
   #?(:cljs
      (:require-macros [unit.nedap.utils.speced.defn :refer [the-defns]])))
@@ -752,3 +753,15 @@
             (let [the-class (Class/forName "[B")]
               (is (-> #'bytes-defn meta :tag #{the-class}))
               (is (= the-class (-> #'bytes-defn meta :arglists first meta :tag #{the-class})))))))))
+
+#?(:clj
+   (deftest nilable-primitive-specs
+     (testing "^:nedap.utils.speced/nilable <primitive hint> is forbidden"
+       (are [input] (try
+                      (eval input)
+                      false
+                      (catch Exception e
+                        (-> e .getCause .getMessage (string/includes? impl.parsing/forbidden-primitives-message))))
+         '(nedap.utils.speced/defn nilable-primitive-specs-1 ^:nedap.utils.speced/nilable ^double [])
+
+         '(nedap.utils.speced/defn nilable-primitive-specs-1 [^:nedap.utils.speced/nilable ^double x])))))