feat: add PrintRoutes() method for debugging routes

_examples/debug/main.go

@@ -0,0 +1,98 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/go-chi/chi/v5/middleware"
+)
+
+func main() {
+	r := chi.NewRouter()
+
+	// Standard middleware
+	r.Use(middleware.Logger)
+	r.Use(middleware.Recoverer)
+
+	// Routes
+	r.Get("/", func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte("Welcome"))
+	})
+
+	// User routes
+	r.Route("/users", func(r chi.Router) {
+		r.Get("/", listUsers)
+		r.Post("/", createUser)
+
+		r.Route("/{userID}", func(r chi.Router) {
+			r.Get("/", getUser)
+			r.Put("/", updateUser)
+			r.Delete("/", deleteUser)
+		})
+	})
+
+	// Article routes
+	r.Route("/articles", func(r chi.Router) {
+		r.Get("/", listArticles)
+		r.Get("/{articleID}", getArticle)
+		r.Post("/", createArticle)
+	})
+
+	// Admin routes
+	adminRouter := chi.NewRouter()
+	adminRouter.Get("/", adminDashboard)
+	adminRouter.Get("/users", adminListUsers)
+	r.Mount("/admin", adminRouter)
+
+	// Print all registered routes
+	fmt.Println("Registered routes:")
+	fmt.Println("==================")
+	r.PrintRoutes()
+	fmt.Println("==================")
+
+	// Start server
+	fmt.Println("\nServer starting on :3000")
+	http.ListenAndServe(":3000", r)
+}
+
+func listUsers(w http.ResponseWriter, r *http.Request) {
+	w.Write([]byte("List users"))
+}
+
+func createUser(w http.ResponseWriter, r *http.Request) {
+	w.Write([]byte("Create user"))
+}
+
+func getUser(w http.ResponseWriter, r *http.Request) {
+	userID := chi.URLParam(r, "userID")
+	w.Write([]byte(fmt.Sprintf("Get user %s", userID)))
+}
+
+func updateUser(w http.ResponseWriter, r *http.Request) {
+	w.Write([]byte("Update user"))
+}
+
+func deleteUser(w http.ResponseWriter, r *http.Request) {
+	w.Write([]byte("Delete user"))
+}
+
+func listArticles(w http.ResponseWriter, r *http.Request) {
+	w.Write([]byte("List articles"))
+}
+
+func getArticle(w http.ResponseWriter, r *http.Request) {
+	w.Write([]byte("Get article"))
+}
+
+func createArticle(w http.ResponseWriter, r *http.Request) {
+	w.Write([]byte("Create article"))
+}
+
+func adminDashboard(w http.ResponseWriter, r *http.Request) {
+	w.Write([]byte("Admin dashboard"))
+}
+
+func adminListUsers(w http.ResponseWriter, r *http.Request) {
+	w.Write([]byte("Admin list users"))
+}

_examples/logging-integration/main.go

@@ -0,0 +1,84 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/go-chi/chi/v5/middleware"
+)
+
+func main() {
+	r := chi.NewRouter()
+	r.Use(middleware.Logger)
+	r.Use(middleware.Recoverer)
+
+	// Register some routes
+	r.Get("/", func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte("Home"))
+	})
+
+	r.Route("/api", func(r chi.Router) {
+		r.Get("/health", func(w http.ResponseWriter, r *http.Request) {
+			w.Write([]byte("OK"))
+		})
+		r.Post("/users", func(w http.ResponseWriter, r *http.Request) {
+			w.Write([]byte("Create user"))
+		})
+		r.Get("/users/{id}", func(w http.ResponseWriter, r *http.Request) {
+			w.Write([]byte("Get user"))
+		})
+	})
+
+	fmt.Println("\n=== Example 1: Using PrintRoutes (simple) ===")
+	r.PrintRoutes()
+
+	fmt.Println("\n=== Example 2: Using PrintRoutesFunc with standard log ===")
+	r.PrintRoutesFunc(func(s string) {
+		log.Println(s)
+	})
+
+	fmt.Println("\n=== Example 3: Using PrintRoutesFunc with custom logger ===")
+	// Simulate a custom logger (like logrus, zap, slog, etc.)
+	customLogger := &CustomLogger{prefix: "[ROUTES]"}
+	r.PrintRoutesFunc(customLogger.Info)
+
+	fmt.Println("\n=== Example 4: Using PrintRoutesFunc with filtering ===")
+	// Only log GET routes
+	r.PrintRoutesFunc(func(s string) {
+		if contains(s, "GET") {
+			fmt.Printf("GET route: %s\n", s)
+		}
+	})
+
+	fmt.Println("\nServer starting on :3000")
+	http.ListenAndServe(":3000", r)
+}
+
+// CustomLogger simulates a structured logging library
+type CustomLogger struct {
+	prefix string
+}
+
+func (l *CustomLogger) Info(msg string) {
+	fmt.Printf("%s [INFO] %s\n", l.prefix, msg)
+}
+
+func (l *CustomLogger) Debug(msg string) {
+	fmt.Printf("%s [DEBUG] %s\n", l.prefix, msg)
+}
+
+func contains(s, substr string) bool {
+	return len(s) >= len(substr) && s[:len(substr)] == substr ||
+		len(s) > len(substr) && findSubstring(s, substr)
+}
+
+func findSubstring(s, substr string) bool {
+	for i := 0; i <= len(s)-len(substr); i++ {
+		if s[i:i+len(substr)] == substr {
+			return true
+		}
+	}
+	return false
+}

mux.go

@@ -3,7 +3,9 @@ package chi
 import (
 	"context"
 	"fmt"
+	"io"
 	"net/http"
+	"os"
 	"strings"
 	"sync"
 )
@@ -526,3 +528,78 @@ func methodNotAllowedHandler(methodsAllowed ...methodTyp) func(w http.ResponseWr
 		w.Write(nil)
 	}
 }
+
+// PrintRoutes prints all registered routes to stdout in a readable format.
+// This is useful for debugging and development purposes.
+//
+// Example output:
+//
+//	[GET]    /
+//	[POST]   /users
+//	[GET]    /users/{id}
+func (mx *Mux) PrintRoutes() {
+	mx.PrintRoutesWithWriter(os.Stdout)
+}
+
+// PrintRoutesWithWriter prints all registered routes to the specified writer.
+// This allows flexibility for testing and custom output destinations.
+func (mx *Mux) PrintRoutesWithWriter(w io.Writer) {
+	// Track routes we've already printed to avoid duplicates
+	printed := make(map[string]bool)
+
+	err := Walk(mx, func(method string, route string, handler http.Handler, middlewares ...func(http.Handler) http.Handler) error {
+		// Create unique key for this route
+		key := fmt.Sprintf("%s %s", method, route)
+
+		// Skip if already printed (can happen with route groups)
+		if printed[key] {
+			return nil
+		}
+		printed[key] = true
+
+		// Print in aligned format
+		fmt.Fprintf(w, "[%-7s] %s\n", method, route)
+		return nil
+	})
+	if err != nil {
+		fmt.Fprintf(w, "Error walking routes: %v\n", err)
+	}
+}
+
+// PrintRoutesFunc prints all registered routes using a custom logging function.
+// This is useful when you want to integrate with existing logging infrastructure.
+//
+// Example with standard log:
+//
+//	r.PrintRoutesFunc(func(s string) { log.Println(s) })
+//
+// Example with logrus:
+//
+//	r.PrintRoutesFunc(logger.Info)
+//
+// Example with slog:
+//
+//	r.PrintRoutesFunc(slog.Info)
+func (mx *Mux) PrintRoutesFunc(logFunc func(string)) {
+	// Track routes we've already printed to avoid duplicates
+	printed := make(map[string]bool)
+
+	// Use chi.Walk to traverse all routes
+	err := Walk(mx, func(method string, route string, handler http.Handler, middlewares ...func(http.Handler) http.Handler) error {
+		// Create unique key for this route
+		key := fmt.Sprintf("%s %s", method, route)
+
+		// Skip if already printed (can happen with route groups)
+		if printed[key] {
+			return nil
+		}
+		printed[key] = true
+
+		// Format and pass to custom logging function
+		logFunc(fmt.Sprintf("[%-7s] %s", method, route))
+		return nil
+	})
+	if err != nil {
+		logFunc(fmt.Sprintf("Error walking routes: %v", err))
+	}
+}