Document behaviour of StrictSlash and PathPrefix better, and add tests to nail this down

mux.go

@@ -109,10 +109,15 @@ func (r *Router) GetRoute(name string) *Route {
 	return r.getNamedRoutes()[name]
 }
 
-// StrictSlash defines the slash behavior for new routes.
+// StrictSlash defines the trailing slash behavior for new routes. The initial
+// value is false.
 //
 // When true, if the route path is "/path/", accessing "/path" will redirect
-// to the former and vice versa.
+// to the former and vice versa. In other words, your application will always
+// see the path as specified in the route.
+//
+// When false, if the route path is "/path", accessing "/path/" will not match
+// this route and vice versa.
 //
 // Special case: when a route sets a path prefix, strict slash is
 // automatically set to false for that route because the redirect behavior

mux_test.go

@@ -151,6 +151,33 @@ func TestPath(t *testing.T) {
 			path:        "/111/222/333",
 			shouldMatch: true,
 		},
+		{
+			title:       "Path route, match with trailing slash in request and path",
+			route:       new(Route).Path("/111/"),
+			request:     newRequest("GET", "http://localhost/111/"),
+			vars:        map[string]string{},
+			host:        "",
+			path:        "/111/",
+			shouldMatch: true,
+		},
+		{
+			title:       "Path route, do not match with trailing slash in path",
+			route:       new(Route).Path("/111/"),
+			request:     newRequest("GET", "http://localhost/111"),
+			vars:        map[string]string{},
+			host:        "",
+			path:        "/111",
+			shouldMatch: false,
+		},
+		{
+			title:       "Path route, do not match with trailing slash in request",
+			route:       new(Route).Path("/111"),
+			request:     newRequest("GET", "http://localhost/111/"),
+			vars:        map[string]string{},
+			host:        "",
+			path:        "/111/",
+			shouldMatch: false,
+		},
 		{
 			title:       "Path route, wrong path in request in request URL",
 			route:       new(Route).Path("/111/222/333"),

route.go

@@ -284,10 +284,15 @@ func (r *Route) Path(tpl string) *Route {
 
 // PathPrefix -----------------------------------------------------------------
 
-// PathPrefix adds a matcher for the URL path prefix. Note that it does not
+// PathPrefix adds a matcher for the URL path prefix. This matches if the given
-// treat slashes specially ("/foobar/" will be matched by the prefix "/foo") so
+// template is a prefix of the full URL path. See Route.Path() for details on
-// in most cases you'll want to use a trailing slash here. See Route.Path() for
+// the tpl argument.
-// details on the tpl argument.
+//
+// Note that it does not treat slashes specially ("/foobar/" will be matched by
+// the prefix "/foo") so you may want to use a trailing slash here.
+//
+// Also note that the setting of Router.StrictSlash() has no effect on routes
+// with a PathPrefix matcher.
 func (r *Route) PathPrefix(tpl string) *Route {
 	r.strictSlash = false
 	r.err = r.addRegexpMatcher(tpl, false, true)