Add Router.List to list all registered paths grouped py method

Author: Sergio Andres Virviescas Santana

router.go

@@ -91,9 +91,10 @@ var (
 // Router is a http.Handler which can be used to dispatch requests to different
 // handler functions via configurable routes
 type Router struct {
-	parent    *Router
-	beginPath string
-	trees     map[string]*node
+	parent          *Router
+	beginPath       string
+	trees           map[string]*node
+	registeredPaths map[string][]string
 
 	// Enables automatic redirection if the current route can't be matched but a
 	// handler for the path with (without) the trailing slash exists.
@@ -149,6 +150,8 @@ type Router struct {
 func New() *Router {
 	return &Router{
 		beginPath:              "/",
+		trees:                  make(map[string]*node),
+		registeredPaths:        make(map[string][]string),
 		RedirectTrailingSlash:  true,
 		RedirectFixedPath:      true,
 		HandleMethodNotAllowed: true,
@@ -223,16 +226,14 @@ func (r *Router) Handle(method, path string, handle fasthttp.RequestHandler) {
 		return
 	}
 
-	if r.trees == nil {
-		r.trees = make(map[string]*node)
-	}
-
 	root := r.trees[method]
 	if root == nil {
 		root = new(node)
 		r.trees[method] = root
 	}
 
+	r.registeredPaths[method] = append(r.registeredPaths[method], path)
+
 	optionalPaths := getOptionalPaths(path)
 
 	// if not has optional paths, adds the original
@@ -310,18 +311,6 @@ func (r *Router) ServeFilesCustom(path string, fs *fasthttp.FS) {
 	})
 }
 
-// Lookup allows the manual lookup of a method + path combo.
-// This is e.g. useful to build a framework around this router.
-// If the path was found, it returns the handle function and the path parameter
-// values. Otherwise the third return value indicates whether a redirection to
-// the same path with an extra / without the trailing slash should be performed.
-func (r *Router) Lookup(method, path string, ctx *fasthttp.RequestCtx) (fasthttp.RequestHandler, bool) {
-	if root := r.trees[method]; root != nil {
-		return root.getValue(path, ctx)
-	}
-	return nil, false
-}
-
 // Handler makes the router implement the fasthttp.ListenAndServe interface.
 func (r *Router) Handler(ctx *fasthttp.RequestCtx) {
 	if r.PanicHandler != nil {
@@ -418,6 +407,23 @@ func (r *Router) Handler(ctx *fasthttp.RequestCtx) {
 	}
 }
 
+// Lookup allows the manual lookup of a method + path combo.
+// This is e.g. useful to build a framework around this router.
+// If the path was found, it returns the handle function and the path parameter
+// values. Otherwise the third return value indicates whether a redirection to
+// the same path with an extra / without the trailing slash should be performed.
+func (r *Router) Lookup(method, path string, ctx *fasthttp.RequestCtx) (fasthttp.RequestHandler, bool) {
+	if root := r.trees[method]; root != nil {
+		return root.getValue(path, ctx)
+	}
+	return nil, false
+}
+
+// List returns all registered routes grouped by method
+func (r *Router) List() map[string][]string {
+	return r.registeredPaths
+}
+
 func (r *Router) allowed(path, reqMethod string) (allow string) {
 	if path == "*" || path == "/*" { // server-wide
 		for method := range r.trees {

router_test.go

@@ -12,6 +12,7 @@ import (
 	"net"
 	"net/http"
 	"os"
+	"reflect"
 	"strings"
 	"testing"
 	"time"
@@ -1029,6 +1030,30 @@ func TestRouterServeFilesCustom(t *testing.T) {
 	}
 }
 
+func TestRouterList(t *testing.T) {
+	expected := map[string][]string{
+		"GET":    []string{"/bar"},
+		"PATCH":  []string{"/foo"},
+		"POST":   []string{"/v1/users/:name/:surname?"},
+		"DELETE": []string{"/v1/users/:id?"},
+	}
+
+	r := New()
+	r.GET("/bar", func(ctx *fasthttp.RequestCtx) {})
+	r.PATCH("/foo", func(ctx *fasthttp.RequestCtx) {})
+
+	v1 := r.Group("/v1")
+	v1.POST("/users/:name/:surname?", func(ctx *fasthttp.RequestCtx) {})
+	v1.DELETE("/users/:id?", func(ctx *fasthttp.RequestCtx) {})
+
+	result := r.List()
+
+	if !reflect.DeepEqual(result, expected) {
+		t.Errorf("Router.List() == %v, want %v", result, expected)
+	}
+
+}
+
 type readWriter struct {
 	net.Conn
 	r bytes.Buffer