feat(backend): initial work on catacumba to plain ring migration

backend/src/uxbox/api/middleware.clj

@@ -0,0 +1,101 @@
+;; This Source Code Form is subject to the terms of the Mozilla Public
+;; License, v. 2.0. If a copy of the MPL was not distributed with this
+;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
+;;
+;; Copyright (c) 2016-2019 Andrey Antukh <niwi@niwi.nz>
+
+(ns uxbox.api.middleware
+  (:require [reitit.core :as rc]
+            [struct.core :as st]
+            [promesa.core :as p]
+            [uxbox.util.data :refer [normalize-attrs]]
+            [uxbox.util.exceptions :as ex]))
+
+;; (extend-protocol rc/Expand
+;;   clojure.lang.Var
+;;   (expand [this opts]
+;;     (merge (rc/expand (deref this) opts)
+;;            {::handler-metadata (meta this)})))
+
+(defn transform-handler
+  [handler]
+  (fn [request respond raise]
+    (try
+      (let [response (handler request)]
+        (if (p/promise? response)
+          (-> response
+              (p/then respond)
+              (p/catch raise))
+          (respond response)))
+      (catch Exception e
+        (raise e)))))
+
+(defn handler
+  [invar]
+  (let [metadata (meta invar)
+        hlrdata (-> metadata
+                    (dissoc :arglist :line :column :file :ns)
+                    (assoc :handler (transform-handler (var-get invar))
+                           :fullname (symbol (str (:ns metadata)) (str (:name metadata)))))]
+    (cond-> hlrdata
+      (:doc metadata) (assoc :description (:doc metadata)))))
+
+(def normalize-params-middleware
+  {:name ::normalize-params-middleware
+   :wrap (fn [handler]
+           (letfn [(transform-request [request]
+                     (if-let [data (get request :query-params)]
+                       (assoc request :query-params (normalize-attrs data))
+                       request))]
+             (fn
+               ([request] (handler (transform-request request)))
+               ([request respond raise]
+                (try
+                  (try
+                    (let [request (transform-request request)]
+                      (handler (transform-request request) respond raise))
+                    (catch Exception e
+                      (raise e))))))))})
+
+
+;; --- Validation
+
+(def parameters-validation-middleware
+  (letfn [(prepare [parameters]
+            (reduce-kv
+             (fn [acc key spec]
+               (let [newkey (case key
+                              :path :path-params
+                              :query :query-params
+                              :body :body-params
+                              (throw (ex-info "Not supported key on :parameters" {})))]
+                 (assoc acc newkey {:key key
+                                    :fn #(st/validate % spec)})))
+             {} parameters))
+
+          (validate [request parameters debug]
+            (reduce-kv
+             (fn [req key spec]
+               (let [[errors, result] ((:fn spec) (get req key))]
+                 (if errors
+                   (ex/raise :type :parameters-validation
+                             :code (:key spec)
+                             :context errors
+                             :message "Invalid data")
+
+                   (assoc-in req [:parameters (:key spec)] result))))
+             request parameters))]
+
+    {:name ::parameters-validation-middleware
+     :compile (fn [route opts]
+                (when-let [parameters (:parameters route)]
+                  (let [parameters (prepare parameters)]
+                    (fn [handler]
+                      (fn
+                        ([request]
+                         (handler (validate request parameters)))
+                        ([request respond raise]
+                         (try
+                           (handler (validate request parameters false) respond raise)
+                           (catch Exception e
+                             (raise e)))))))))}))