Fix returns 500 when exception is thrown from handle-page middleware (#27526)

* fix throwing exceptions in handle-paging mw

src/metabase/server/handler.clj

@@ -50,8 +50,8 @@
    #'mw.browser-cookie/ensure-browser-id-cookie ; add cookie to identify browser; add `:browser-id` to the request
    #'mw.security/add-security-headers           ; Add HTTP headers to API responses to prevent them from being cached
    #'mw.json/wrap-json-body                     ; extracts json POST body and makes it avaliable on request
-   #'mw.json/wrap-streamed-json-response        ; middleware to automatically serialize suitable objects as JSON in responses
    #'mw.offset-paging/handle-paging             ; binds per-request parameters to handle paging
+   #'mw.json/wrap-streamed-json-response        ; middleware to automatically serialize suitable objects as JSON in responses
    #'wrap-keyword-params                        ; converts string keys in :params to keyword keys
    #'wrap-params                                ; parses GET and POST params as :query-params/:form-params and both as :params
    #'mw.misc/maybe-set-site-url                 ; set the value of `site-url` if it hasn't been set yet
@@ -68,7 +68,8 @@
    #'mw.ssl/redirect-to-https-middleware])
 ;; ▲▲▲ PRE-PROCESSING ▲▲▲ happens from BOTTOM-TO-TOP
 
-(defn- apply-middleware [handler]
+(defn- apply-middleware
+  [handler]
   (reduce
    (fn [handler middleware-fn]
      (middleware-fn handler))

test/metabase/server/middleware/offset_paging_test.clj

 (ns metabase.server.middleware.offset-paging-test
   (:require
+   [cheshire.core :as json]
+   [clojure.java.io :as io]
    [clojure.test :refer :all]
+   [metabase.server.handler :as handler]
    [metabase.server.middleware.offset-paging :as mw.offset-paging]
-   [ring.middleware.keyword-params :refer [wrap-keyword-params]]
-   [ring.middleware.params :refer [wrap-params]]
+   [metabase.server.middleware.security :as mw.security]
    [ring.mock.request :as ring.mock]
-   [ring.util.response :as response]
-   [schema.core :as s]))
+   [ring.util.response :as response])
+  (:import
+   (java.io PipedInputStream)))
 
 (defn- handler [request]
-  (let [handler* (-> (fn [request respond _]
-                       (respond (response/response {:limit  mw.offset-paging/*limit*
-                                                    :offset mw.offset-paging/*offset*
-                                                    :paged? mw.offset-paging/*paged?*
-                                                    :params (:params request)})))
-                     mw.offset-paging/handle-paging
-                     wrap-keyword-params
-                     wrap-params)
-        respond identity
-        raise   (fn [e] (throw e))]
+  (let [handler  (fn [request respond _]
+                   (respond (response/response {:limit  mw.offset-paging/*limit*
+                                                :offset mw.offset-paging/*offset*
+                                                :paged? mw.offset-paging/*paged?*
+                                                :params (:params request)})))
+        handler* (#'handler/apply-middleware handler)
+        respond  identity
+        raise    (fn [e] (throw e))]
     (handler* request respond raise)))
 
+(defn- read-response
+  "Responses from our hanlders are inputstream, this is read the stream into real body."
+  [response]
+  (update response :body
+          (fn [body]
+            (if (instance? PipedInputStream body)
+              (with-open [r (io/reader body)]
+                (json/parse-stream r))
+              body))))
+
 (deftest paging-test
   (testing "no paging params"
-    (is (= {:status  200
-            :headers {}
-            :body    {:limit  nil
-                      :offset nil
-                      :paged? false
-                      :params {}}}
-           (handler (ring.mock/request :get "/")))))
+    (is (=? {:status  200
+             :body    {"limit"  nil
+                       "offset" nil
+                       "paged?" false
+                       "params" {}}}
+            (read-response (handler (ring.mock/request :get "/"))))))
   (testing "w/ paging params"
-    (is (= {:status  200
-            :headers {}
-            :body    {:limit  100
-                      :offset 200
-                      :paged? true
-                      :params {:whatever "true"}}}
-           (handler (ring.mock/request :get "/" {:offset "200", :limit "100", :whatever "true"})))))
+    (is (=? {:status  200
+             :body    {"limit"  100
+                       "offset" 200
+                       "paged?" true
+                       "params" {"whatever" "true"}}}
+            (read-response (handler (ring.mock/request :get "/" {:offset "200", :limit "100", :whatever "true"}))))))
+
   (testing "invalid params"
-    (is (schema= {:status  (s/eq 400)
-                  :headers s/Any
-                  :body {:message #"Error parsing paging parameters.*" s/Keyword s/Any}}
-                 (handler (ring.mock/request :get "/" {:offset "abc", :limit "100"}))))))
+    (is (=? {:status  400
+             :headers (mw.security/security-headers)
+             :body    {"message" #"Error parsing paging parameters.*"}}
+            (read-response (handler (ring.mock/request :get "/" {:offset "abc", :limit "100"})))))))