CLJS-3370: improved uuid regex to only accept hex characters (#166)

Co-authored-by: Paula Gearon <gearon@gmail.com>

Author: swannodette

src/main/cljs/cljs/core.cljs

@@ -12062,7 +12062,7 @@ reduces them without incurring seq initialization"
     (throw (js/Error. (parsing-err s)))))
 
 (def ^:private uuid-regex
-  #"^[0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z]-[0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z]-[0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z]-[0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z]-[0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z]$")
+  #"^[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]-[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]-[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]-[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]-[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]$")
 
 (defn parse-uuid
   "Parse a string representing a UUID and return a UUID instance,

src/test/cljs/cljs/parse_test.cljs

@@ -80,7 +80,15 @@
   (are [s] ;; throw on invalid type (not string)
     (try (parse-uuid s) (is false) (catch :default _ (is true)))
     123
-    nil))
+    nil)
+  ;; parse the nil uuid
+  (is (parse-uuid "00000000-0000-0000-0000-000000000000"))
+  ;; parse a version 1 UUID
+  (is (parse-uuid "123e4567-e89b-12d3-a456-426614174000"))
+  ;; parse a version 2 UUID
+  (is (parse-uuid "123e4567-e89b-22d3-a456-426614174000"))
+  ;; ensure that bad characters are invalid
+  (is (nil? (parse-uuid "123e4567-eg9b-12d3-a456-426614174000"))))
 
 (deftest test-parse-boolean
   (is (identical? true (parse-boolean "true")))