Various fixes based on PR feedback

- Adds tests
- Fix broken async implementation

Author: expez

ring-core/src/ring/middleware/multipart_params.clj

@@ -9,6 +9,7 @@
     ring.middleware.multipart-params.temp-file/temp-file-store"
   (:require [ring.util.codec :refer [assoc-conj]]
             [ring.util.request :as req]
+            [ring.util.response :as response]
             [ring.util.parsing :refer [re-charset]])
   (:import [org.apache.commons.fileupload UploadContext
                                           FileItemIterator
@@ -174,9 +175,11 @@
       (try
         (handler (multipart-params-request request options))
         (catch InvalidFileNameException e
-            {:status 400 :body (.getMessage e)})))
+          (response/bad-request (.getMessage e)))))
      ([request respond raise]
       (try
         (handler (multipart-params-request request options) respond raise)
         (catch InvalidFileNameException e
-            {:status 400 :body (.getMessage e)}))))))
+          (handler request
+                   (fn [_] (respond (response/bad-request (.getMessage e))))
+                   raise)))))))

ring-core/test/ring/middleware/multipart_params/test/multipart_params.clj

@@ -0,0 +1,27 @@
+(ns ring.middleware.multipart-params.test.multipart-params
+  (:require [clojure.test :refer :all]
+            [ring.middleware.multipart-params :refer :all]
+            [ring.util.response :as response])
+  (:import org.apache.commons.fileupload.InvalidFileNameException))
+
+(deftest wrap-multipart-params-error-test
+  (let [invalid-file-name "foo\\0.bar"
+        error-msg (str "Invalid file name: " invalid-file-name)]
+    (with-redefs [multipart-params-request
+                  (fn [& _]
+                    (throw (InvalidFileNameException.
+                            invalid-file-name
+                            error-msg)))]
+      (testing "Synchronous error response"
+        (let [handler (wrap-multipart-params (constantly (response/response "Ok")))]
+          (is (= (response/bad-request error-msg)
+                 (handler {:uri "/foo/bar"})))))
+      (testing "Asynchronous error response"
+        (let [handler (wrap-multipart-params (fn [_ respond _]
+                                               (respond (response/response "Ok"))))
+              response (promise)
+              exception (promise)]
+          (handler {:uri "/foo/bar"} response exception)
+          (is (= (response/bad-request error-msg)
+                 (deref response 2000 :timed-out)))
+          (is (not (realized? exception))))))))