From b23b2611b3fa35803bc00dfe9359ec7bd22b9080 Mon Sep 17 00:00:00 2001
From: Emile Vauge <emile@vauge.com>
Date: Tue, 19 Dec 2017 17:00:12 +0100
Subject: [PATCH] Add non regex pathPrefix

---
 server/rules.go      | 25 +++++++++++++++--
 server/rules_test.go | 64 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 87 insertions(+), 2 deletions(-)

diff --git a/server/rules.go b/server/rules.go
index 661b80224..be7f2b033 100644
--- a/server/rules.go
+++ b/server/rules.go
@@ -54,11 +54,32 @@ func (r *Rules) path(paths ...string) *mux.Route {
 func (r *Rules) pathPrefix(paths ...string) *mux.Route {
 	router := r.route.route.Subrouter()
 	for _, path := range paths {
-		router.PathPrefix(strings.TrimSpace(path))
+		buildPath(path, router)
 	}
 	return r.route.route
 }
 
+func buildPath(path string, router *mux.Router) {
+	cleanPath := strings.TrimSpace(path)
+	// {} are used to define a regex pattern in http://www.gorillatoolkit.org/pkg/mux.
+	// if we find a { in the path, that means we use regex, then the gorilla/mux implementation is chosen
+	// otherwise, we use a lightweight implementation
+	if strings.Contains(cleanPath, "{") {
+		router.PathPrefix(cleanPath)
+	} else {
+		m := &prefixMatcher{prefix: cleanPath}
+		router.NewRoute().MatcherFunc(m.Match)
+	}
+}
+
+type prefixMatcher struct {
+	prefix string
+}
+
+func (m *prefixMatcher) Match(r *http.Request, _ *mux.RouteMatch) bool {
+	return strings.HasPrefix(r.URL.Path, m.prefix) || strings.HasPrefix(r.URL.Path, m.prefix+"/")
+}
+
 type bySize []string
 
 func (a bySize) Len() int           { return len(a) }
@@ -111,7 +132,7 @@ func (r *Rules) pathPrefixStrip(paths ...string) *mux.Route {
 	r.route.stripPrefixes = paths
 	router := r.route.route.Subrouter()
 	for _, path := range paths {
-		router.PathPrefix(strings.TrimSpace(path))
+		buildPath(path, router)
 	}
 	return r.route.route
 }
diff --git a/server/rules_test.go b/server/rules_test.go
index f0ad65edd..7d3712289 100644
--- a/server/rules_test.go
+++ b/server/rules_test.go
@@ -192,3 +192,67 @@ type fakeHandler struct {
 }
 
 func (h *fakeHandler) ServeHTTP(http.ResponseWriter, *http.Request) {}
+
+func TestPathPrefix(t *testing.T) {
+	testCases := []struct {
+		desc string
+		path string
+		urls map[string]bool
+	}{
+		{
+			desc: "leading slash",
+			path: "/bar",
+			urls: map[string]bool{
+				"http://foo.com/bar":  true,
+				"http://foo.com/bar/": true,
+			},
+		},
+		{
+			desc: "leading trailing slash",
+			path: "/bar/",
+			urls: map[string]bool{
+				"http://foo.com/bar":  false,
+				"http://foo.com/bar/": true,
+			},
+		},
+		{
+			desc: "no slash",
+			path: "bar",
+			urls: map[string]bool{
+				"http://foo.com/bar":  false,
+				"http://foo.com/bar/": false,
+			},
+		},
+		{
+			desc: "trailing slash",
+			path: "bar/",
+			urls: map[string]bool{
+				"http://foo.com/bar":  false,
+				"http://foo.com/bar/": false,
+			},
+		},
+	}
+
+	for _, test := range testCases {
+		test := test
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			rls := &Rules{
+				route: &serverRoute{
+					route: &mux.Route{},
+				},
+			}
+
+			rt := rls.pathPrefix(test.path)
+
+			for testURL, expectedMatch := range test.urls {
+				req := testhelpers.MustNewRequest(http.MethodGet, testURL, nil)
+				match := rt.Match(req, &mux.RouteMatch{})
+				if match != expectedMatch {
+					t.Errorf("Error matching %s with %s, got %v expected %v", test.path, testURL, match, expectedMatch)
+				}
+			}
+		})
+	}
+}