From c86f042f54ee9200b034769635a7ecab46432939 Mon Sep 17 00:00:00 2001
From: Juho Teperi <juho.teperi@iki.fi>
Date: Fri, 15 Mar 2019 17:33:46 +0200
Subject: [PATCH] Implement #238, handle trailing slashes in frontend
 match-by-path

---
 .../reitit-frontend/src/reitit/frontend.cljs  | 24 +++++-
 test/cljs/reitit/frontend/core_test.cljs      | 86 +++++++++++++++++++
 2 files changed, 106 insertions(+), 4 deletions(-)

diff --git a/modules/reitit-frontend/src/reitit/frontend.cljs b/modules/reitit-frontend/src/reitit/frontend.cljs
index 8145404a..5ff4f09a 100644
--- a/modules/reitit-frontend/src/reitit/frontend.cljs
+++ b/modules/reitit-frontend/src/reitit/frontend.cljs
@@ -1,5 +1,6 @@
 (ns reitit.frontend
   (:require [clojure.set :as set]
+            [clojure.string :as str]
             [reitit.coercion :as coercion]
             [reitit.coercion :as rc]
             [reitit.core :as r])
@@ -16,10 +17,18 @@
 
 (defn match-by-path
   "Given routing tree and current path, return match with possibly
-  coerced parameters. Return nil if no match found."
+  coerced parameters. Returns nil if no match found."
   [router path]
-  (let [uri (.parse Uri path)]
-    (if-let [match (r/match-by-path router (.getPath uri))]
+  (let [uri (.parse Uri path)
+        path (.getPath uri)]
+    (if-let [match (or (r/match-by-path router path)
+                       (if-let [trailing-slash-handling (:trailing-slash-handling (r/options router))]
+                         (if (str/ends-with? path "/")
+                           (if (not= trailing-slash-handling :add)
+                             (r/match-by-path router (subs path 0 (dec (count path)))))
+                           (if (not= trailing-slash-handling :remove)
+                             (r/match-by-path router (str path "/"))))))]
+      ;; User can update browser location in on-navigate call using replace-state
       (let [q (query-params uri)
             match (assoc match :query-params q)
             ;; Return uncoerced values if coercion is not enabled - so
@@ -40,7 +49,14 @@
 
 (defn router
   "Create a `reitit.core.router` from raw route data and optionally an options map.
-  Enables request coercion. See [[reitit.core/router]] for details on options."
+  Enables request coercion. See [[reitit.core/router]] for details on options.
+
+  Additional options:
+
+  | key          | description |
+  | -------------|-------------|
+  | :trailing-slash-handling | TODO |
+  "
   ([raw-routes]
    (router raw-routes {}))
   ([raw-routes opts]
diff --git a/test/cljs/reitit/frontend/core_test.cljs b/test/cljs/reitit/frontend/core_test.cljs
index 20009088..1a56934b 100644
--- a/test/cljs/reitit/frontend/core_test.cljs
+++ b/test/cljs/reitit/frontend/core_test.cljs
@@ -104,3 +104,89 @@
                  (capture-console
                    (fn []
                      (rf/match-by-name! router ::foo {}))))))))))
+
+
+(deftest trailing-slash-handling-test
+  (testing ":both"
+    (let [router (r/router ["/"
+                            ["" ::frontpage]
+                            ["foo" ::foo]
+                            ["bar/" ::bar]]
+                           {:trailing-slash-handling :both})]
+      (is (= (r/map->Match
+               {:template "/foo"
+                :data {:name ::foo}
+                :path-params {}
+                :query-params {}
+                :path "/foo"
+                :parameters {:query {}
+                             :path {}}})
+             (rf/match-by-path router "/foo/")
+             (rf/match-by-path router "/foo")))
+
+      (is (= (r/map->Match
+               {:template "/bar/"
+                :data {:name ::bar}
+                :path-params {}
+                :query-params {}
+                :path "/bar/"
+                :parameters {:query {}
+                             :path {}}})
+             (rf/match-by-path router "/bar/")
+             (rf/match-by-path router "/bar"))) ))
+
+  (testing ":add"
+    (let [router (r/router ["/"
+                            ["" ::frontpage]
+                            ["foo" ::foo]
+                            ["bar/" ::bar]]
+                           {:trailing-slash-handling :add})]
+      (is (= (r/map->Match
+               {:template "/foo"
+                :data {:name ::foo}
+                :path-params {}
+                :query-params {}
+                :path "/foo"
+                :parameters {:query {}
+                             :path {}}})
+             (rf/match-by-path router "/foo")))
+      (is (nil? (rf/match-by-path router "/foo/")))
+
+      (is (= (r/map->Match
+               {:template "/bar/"
+                :data {:name ::bar}
+                :path-params {}
+                :query-params {}
+                :path "/bar/"
+                :parameters {:query {}
+                             :path {}}})
+             (rf/match-by-path router "/bar/")
+             (rf/match-by-path router "/bar")))))
+
+  (testing ":remove"
+    (let [router (r/router ["/"
+                            ["" ::frontpage]
+                            ["foo" ::foo]
+                            ["bar/" ::bar]]
+                           {:trailing-slash-handling :remove})]
+      (is (= (r/map->Match
+               {:template "/foo"
+                :data {:name ::foo}
+                :path-params {}
+                :query-params {}
+                :path "/foo"
+                :parameters {:query {}
+                             :path {}}})
+             (rf/match-by-path router "/foo/")
+             (rf/match-by-path router "/foo")))
+
+      (is (= (r/map->Match
+               {:template "/bar/"
+                :data {:name ::bar}
+                :path-params {}
+                :query-params {}
+                :path "/bar/"
+                :parameters {:query {}
+                             :path {}}})
+             (rf/match-by-path router "/bar/")))
+      (is (nil? (rf/match-by-path router "/bar"))))))