Fix #8 unhandled exception when parsing malformed body

Author: LukasRychtecky

src/duct/handler/static.clj

@@ -49,6 +49,11 @@
 (defmethod ig/init-key ::bad-request [_ response]
   (make-handler (assoc response :status 400)))
 
+(defmethod ig/init-key ::bad-request-malformed [_ response]
+  (let [handler (make-handler (assoc response :status 400))]
+    (fn [_ _ request]
+      (handler request))))
+
 (defmethod ig/init-key ::not-found [_ response]
   (make-handler (assoc response :status 404)))
 

src/duct/middleware/web.clj

@@ -123,5 +123,10 @@
     (merge-with deep-merge a b)
     b))
 
-(defmethod ig/init-key ::format [_ options]
-  #(mm/wrap-format % (deep-merge mc/default-options options)))
+(defmethod ig/init-key ::format [_ {:keys [malformed-handler]
+                                    :as options
+                                    :or {malformed-handler
+                                         (ig/ref :duct.handler.static/bad-request-malformed)}}]
+  #(mm/wrap-exception
+     (mm/wrap-format % (deep-merge mc/default-options options))
+     malformed-handler))

src/duct/module/web.clj

@@ -1,6 +1,7 @@
 (ns duct.module.web
   (:require [clojure.java.io :as io]
             [clojure.string :as str]
+            [cheshire.core :as cheshire]
             [duct.core :as core]
             [duct.core.env :as env]
             [duct.core.merge :as merge]
@@ -70,6 +71,7 @@
 
 (def ^:private base-config
   {:duct.handler.static/bad-request           (plaintext-response "Bad Request")
+   :duct.handler.static/bad-request-malformed (plaintext-response "Bad Request Malformed")
    :duct.handler.static/not-found             (plaintext-response "Not Found")
    :duct.handler.static/method-not-allowed    (plaintext-response "Method Not Allowed")
    :duct.handler.static/internal-server-error (plaintext-response "Internal Server Error")
@@ -80,6 +82,8 @@
 
 (def ^:private api-config
   {:duct.handler.static/bad-request           {:body ^:displace {:error :bad-request}}
+   :duct.handler.static/bad-request-malformed {:body (cheshire/generate-string {:error "Malformed request body"})
+                                               :headers {"Content-Type" "application/json"}}
    :duct.handler.static/not-found             {:body ^:displace {:error :not-found}}
    :duct.handler.static/method-not-allowed    {:body ^:displace {:error :method-not-allowed}}
    :duct.handler.static/internal-server-error
@@ -113,6 +117,7 @@
 
 (defn- site-config [project-ns]
   {:duct.handler.static/bad-request           (html-response error-400)
+   :duct.handler.static/bad-request-malformed (html-response error-400)
    :duct.handler.static/not-found             (html-response error-404)
    :duct.handler.static/method-not-allowed    (html-response error-405)
    :duct.handler.static/internal-server-error (html-response error-500)