metosin · opqdonut · Apr 8, 2025 · Apr 8, 2025 · Apr 8, 2025 · Apr 8, 2025
diff --git a/.gitignore b/.gitignore
@@ -15,3 +15,4 @@ figwheel_server.log
 /.idea
 .clj-kondo
 .shadow-cljs
+.cache
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -12,6 +12,12 @@ We use [Break Versioning][breakver]. The version numbers follow a `<major>.<mino
 
 [breakver]: https://github.com/ptaoussanis/encore/blob/master/BREAK-VERSIONING.md
 
+## UNRELEASED
+
+* Improvements to mime type handling in `create-file-handler` and `create-resource-handler` [#733](https://github.com/metosin/reitit/pull/733)
+  * New `:mime-types` option to configure a map from file extension to mime type
+  * Don't set Content-Type header at all if mime type is not known
+
 ## 0.8.0 (2025-03-28)
 
 **[compare](https://github.com/metosin/reitit/compare/0.7.2..0.8.0)**

diff --git a/dev-resources/public/site.webmanifest b/dev-resources/public/site.webmanifest
@@ -0,0 +1,3 @@
+{
+  "name": "Example"
+}
diff --git a/modules/reitit-ring/src/reitit/ring.cljc b/modules/reitit-ring/src/reitit/ring.cljc
@@ -227,7 +227,7 @@
    ;; TODO: ring.middleware.head/wrap-head
    ;; TODO: handle etags
    (defn -create-file-or-resource-handler
-     [response-fn {:keys [parameter root path loader allow-symlinks? index-files index-redirect? canonicalize-uris? paths not-found-handler]
+     [response-fn {:keys [parameter root path loader allow-symlinks? index-files index-redirect? canonicalize-uris? paths not-found-handler mime-types]
                    :or {parameter (keyword "")
                         root "public"
                         index-files ["index.html"]
@@ -250,9 +250,11 @@
            join-paths (fn [& paths]
                         (str/replace (str/replace (str/join "/" paths) #"([/]+)" "/") #"/$" ""))
            response (fn [path]
-                      (if-let [response (or (paths (join-paths "/" path))
-                                            (response-fn path options))]
-                        (response/content-type response (mime-type/ext-mime-type path))))
+                      (when-let [response (or (paths (join-paths "/" path))
+                                              (response-fn path options))]
+                        (if-let [content-type (mime-type/ext-mime-type path mime-types)]
+                          (response/content-type response content-type)
+                          response)))
            path-or-index-response (fn [path uri]
                                     (or (response path)
                                         (when (or canonicalize-uris? (str/ends-with? uri "/"))
@@ -295,7 +297,8 @@
      | :index-files        | optional vector of index-files to look in a resource directory, defaults to `[\"index.html\"]`
      | :index-redirect?    | optional boolean: if true (default false), redirect to index file, if false serve it directly
      | :canonicalize-uris? | optional boolean: if true (default), try to serve index files for non directory paths (paths that end with slash)
-     | :not-found-handler  | optional handler function to use if the requested resource is missing (404 Not Found)"
+     | :not-found-handler  | optional handler function to use if the requested resource is missing (404 Not Found)
+     | :mime-types         | optional map of filename extensions to mime-types that will be used to guess the content type in addition to the ones defined in ring.util.mime-type/default-mime-types"
      ([]
       (create-resource-handler nil))
      ([opts]
@@ -314,7 +317,8 @@
      | :index-files        | optional vector of index-files to look in a resource directory, defaults to `[\"index.html\"]`
      | :index-redirect?    | optional boolean: if true (default false), redirect to index file, if false serve it directly
      | :canonicalize-uris? | optional boolean: if true (default), try to serve index files for non directory paths (paths that end with slash)
-     | :not-found-handler  | optional handler function to use if the requested resource is missing (404 Not Found)"
+     | :not-found-handler  | optional handler function to use if the requested resource is missing (404 Not Found)
+     | :mime-types         | optional map of filename extensions to mime-types that will be used to guess the content type in addition to the ones defined in ring.util.mime-type/default-mime-types"
      ([]
       (create-file-handler nil))
      ([opts]

diff --git a/test/cljc/reitit/ring_test.cljc b/test/cljc/reitit/ring_test.cljc
@@ -742,7 +742,22 @@
                  (let [response (app (request "/docs/"))]
                    (is (= (redirect "/docs/index.html") response)))
                  (let [response (app (request "/foobar"))]
-                   (is (= 404 (:status response))))))))))))
+                   (is (= 404 (:status response)))))))
+
+           (testing "with additional mime types"
+             (let [app (ring/ring-handler
+                        (ring/router
+                         ["/*" (create {:mime-types {"webmanifest" "application/manifest+json"}})])
+                        (ring/create-default-handler))
+                   response (app (request "/site.webmanifest"))]
+                  (is (= "application/manifest+json" (get-in response [:headers "Content-Type"])))))
+           (testing "when content type cannot be guessed"
+             (let [app (ring/ring-handler
+                        (ring/router
+                         ["/*" (create nil)])
+                        (ring/create-default-handler))
+                   response (app (request "/site.webmanifest"))]
+                  (is (not (contains? (:headers response) "Content-Type"))))))))))
 
 #?(:clj
    (deftest file-resource-handler-not-found-test
-Original file line number
+Diff line change
@@ Expand Up / @@ -15,3 +15,4 @@ figwheel_server.log @@
     /.idea
     .clj-kondo
     .shadow-cljs
+    .cache