fixes bug with invalid handler name for metrics (#29529)

closes https://github.com/grafana/grafana/issues/29487

Signed-off-by: bergquist <carl.bergquist@gmail.com>

pkg/api/routing/route_register.go

@@ -118,22 +118,24 @@ func (rr *routeRegister) Register(router Router) {
 
 func (rr *routeRegister) route(pattern, method string, handlers ...macaron.Handler) {
 	h := make([]macaron.Handler, 0)
+	fullPattern := rr.prefix + pattern
+
 	for _, fn := range rr.namedMiddleware {
-		h = append(h, fn(pattern))
+		h = append(h, fn(fullPattern))
 	}
 
 	h = append(h, rr.subfixHandlers...)
 	h = append(h, handlers...)
 
 	for _, r := range rr.routes {
-		if r.pattern == rr.prefix+pattern && r.method == method {
+		if r.pattern == fullPattern && r.method == method {
 			panic("cannot add duplicate route")
 		}
 	}
 
 	rr.routes = append(rr.routes, route{
 		method:   method,
-		pattern:  rr.prefix + pattern,
+		pattern:  fullPattern,
 		handlers: h,
 	})
 }

pkg/api/routing/route_register_test.go

@@ -214,8 +214,13 @@ func TestNamedMiddlewareRouteRegister(t *testing.T) {
 		{method: "GET", pattern: "/user/admin/all", handlers: emptyHandlers(5)},
 	}
 
+	namedMiddlewares := map[string]bool{}
 	// Setup
-	rr := NewRouteRegister(emptyHandler)
+	rr := NewRouteRegister(func(name string) macaron.Handler {
+		namedMiddlewares[name] = true
+
+		return struct{ name string }{name: name}
+	})
 
 	rr.Delete("/admin", emptyHandler("1"))
 	rr.Get("/down", emptyHandler("1"), emptyHandler("2"))
@@ -247,6 +252,10 @@ func TestNamedMiddlewareRouteRegister(t *testing.T) {
 			t.Errorf("want %s got %v", testTable[i].pattern, fr.route[i].pattern)
 		}
 
+		if _, exist := namedMiddlewares[testTable[i].pattern]; !exist {
+			t.Errorf("could not find named route named %s", testTable[i].pattern)
+		}
+
 		if len(testTable[i].handlers) != len(fr.route[i].handlers) {
 			t.Errorf("want %d handlers got %d handlers \ntestcase: %v\nroute: %v\n",
 				len(testTable[i].handlers),