Add form-decode-map function

Author: weavejester

src/ring/util/codec.clj

@@ -166,6 +166,24 @@
       (zero? i) (MapEntry. "" (.substring s (inc i)))
       :else     (MapEntry. s ""))))
 
+(defn form-decode-map
+  "Decode the supplied www-form-urlencoded string using the specified encoding,
+  or UTF-8 by default. Expects an encoded map of key/value pairs as defined by:
+  https://url.spec.whatwg.org/#urlencoded-parsing"
+  ([encoded]
+   (form-decode-map encoded utf-8))
+  ([^String encoded encoding]
+   (reduce
+    (fn [m param]
+      (let [kv (split-key-value-pair param)
+            k  (form-decode-str (key kv) encoding)
+            v  (form-decode-str (val kv) encoding)]
+        (if (and k v)
+          (assoc-conj m k v)
+          m)))
+    {}
+    (tokenized encoded "&"))))
+
 (defn form-decode
   "Decode the supplied www-form-urlencoded string using the specified encoding,
   or UTF-8 by default. If the encoded value is a string, a string is returned.
@@ -175,13 +193,4 @@
   ([^String encoded encoding]
    (if-not (.contains encoded "=")
      (form-decode-str encoded encoding)
-     (reduce
-      (fn [m param]
-        (let [kv (split-key-value-pair param)
-              k  (form-decode-str (key kv) encoding)
-              v  (form-decode-str (val kv) encoding)]
-          (if (and k v)
-            (assoc-conj m k v)
-            m)))
-      {}
-      (tokenized encoded "&")))))
+     (form-decode-map encoded encoding))))

test/ring/util/test/codec.clj

@@ -61,6 +61,30 @@
   (is (= (form-decode-str "foo=bar+baz" nil) "foo=bar baz"))
   (is (= (form-decode-str "foo=bar+baz" "UTF-8") "foo=bar baz")))
 
+(deftest test-form-decode-map
+  (are [x y] (= (form-decode-map x) y)
+    "foo"     {"foo" ""}
+    "a=b"     {"a" "b"}
+    "a=b&c=d" {"a" "b" "c" "d"}
+    "foo+bar" {"foo bar" ""}
+    "a=b+c"   {"a" "b c"}
+    "a=b%2Fc" {"a" "b/c"}
+    "a=b&c"   {"a" "b" "c" ""}
+    "a=&b=c"  {"a" "" "b" "c"}
+    "a&b=c"   {"a" "" "b" "c"}
+    "="       {"" ""}
+    "a="      {"a" ""}
+    "=b"      {"" "b"})
+  (testing "invalid URL encoding"
+    (are [x y] (= (form-decode-map x) y)
+      "%=b" {}
+      "a=%" {}
+      "%=%" {}))
+  (is (= (form-decode-map "a=foo%FE%FF%00%2Fbar" "UTF-16")
+         {"a" "foo/bar"}))
+  (is (= (form-decode-map "a=foo%2Fbar" nil)
+         {"a" "foo/bar"})))
+
 (deftest test-form-decode
   (are [x y] (= (form-decode x) y)
     "foo"     "foo"