Add :module-middleware config option

Author: weavejester

README.md

@@ -33,18 +33,24 @@ handler.
 
 There are four top level options available:
 
-- `:routes` - the Reitit routing data
+- `:routes`     - the Reitit routing data
 - `:middleware` - a vector of middleware to apply to the Ring handler
-- `:data` - data to add to every Reitit route
+- `:module-middleware` - the same as above, but designed for modules
+- `:data`     - data to add to every Reitit route
 - `:handlers` - a vector of handlers to fall back
 
 The `:data` key takes a map and acts as it does in Reitit, except for
 the following keys:
 
 - `:muuntaja` - a map of Muuntaja options to be merged with the defaults
 - `:coercion` - one of: `:malli`, `:schema` or `:spec`
+- `:module-middleware` - a vector of middleware applied only if the
+                         route matches
 
-These keys will automatically add relevant middleware.
+The `:module-middleware`  keys work the same as the `:middleware` key but
+are applied last, as the outermost middleware. They are intended to allow
+a base set of middleware to be applied by modules, without interfering
+with middleware that is set by users.
 
 The `:duct.handler.reitit/default` key will initiate into a handler
 using the Reitit `create-default-handler` function. It takes the

src/duct/router/reitit.clj

@@ -47,11 +47,18 @@
     (-> (update :coercion (comp var-get requiring-resolve coercion-engines))
         (update :middleware #(into coercion-middleware %)))))
 
+(defn- merge-module-middleware [options]
+  (-> options
+      (dissoc :module-middleware)
+      (update :middleware #(into (vec (:module-middleware options)) %))))
+
 (defmethod ig/init-key :duct.router/reitit [_ options]
   (let [opts   (-> options
+                   (merge-module-middleware)
+                   (update-data merge-module-middleware)
                    (update-data convert-coercion)
                    (update-data convert-muuntaja))
         router (ring/router (:routes opts) opts)]
     (if-some [handlers (seq (:handlers opts))]
       (ring/ring-handler router (apply ring/routes handlers) opts)
-      (ring/ring-handler router opts))))
+      (ring/ring-handler router nil opts))))

test/duct/router/reitit_test.clj

@@ -65,3 +65,20 @@
            (router {:request-method :post, :uri "/"})))
     (is (= {:status 406, :body "406"}
            (router {:request-method :post, :uri "/406"})))))
+
+(defn- wrap-header [handler header value]
+  (fn [request]
+    (-> (handler request)
+        (assoc-in [:headers header] value))))
+
+(deftest middleware-test
+  (let [handler (constantly {:status 200, :body "Hello World"})
+        config  {:duct.router/reitit
+                 {:routes {"/" {:get {:handler handler}}}
+                  :module-middleware [[wrap-header "X-One" "1"]]
+                  :middleware [[wrap-header "X-Two" "2"]]
+                  :data {:module-middleware [[wrap-header "X-Three" "3"]]
+                         :middleware [[wrap-header "X-Four" "4"]]}}}
+        router  (:duct.router/reitit (ig/init config))]
+    (is (= {"X-One" "1", "X-Two" "2", "X-Three" "3", "X-Four" "4"}
+           (:headers (router {:request-method :get, :uri "/"}))))))