recover middleware support print stack trace

middleware/recover/README.md

@@ -41,12 +41,24 @@ type Config struct {
 	//
 	// Optional. Default: nil
 	Next func(c *fiber.Ctx) bool
+
+	// EnableStackTrace enables handling stack trace
+	//
+	// Optional. Default: false
+	EnableStackTrace bool
+
+	// StackTraceHandler defines a function to handle stack trace
+	//
+	// Optional. Default: defaultStackTraceHandler
+	StackTraceHandler func(e interface{})
 }
 ```
 
 ### Default Config
 ```go
 var ConfigDefault = Config{
-	Next: nil,
+	Next:              nil,
+	EnableStackTrace:  false,
+	StackTraceHandler: defaultStackTraceHandler,
 }
 ```

middleware/recover/config.go

@@ -10,11 +10,25 @@ type Config struct {
 	//
 	// Optional. Default: nil
 	Next func(c *fiber.Ctx) bool
+
+	// EnableStackTrace enables handling stack trace
+	//
+	// Optional. Default: false
+	EnableStackTrace bool
+
+	// StackTraceHandler defines a function to handle stack trace
+	//
+	// Optional. Default: defaultStackTraceHandler
+	StackTraceHandler func(e interface{})
 }
 
+var defaultStackTraceBufLen = 1024
+
 // ConfigDefault is the default config
 var ConfigDefault = Config{
-	Next: nil,
+	Next:              nil,
+	EnableStackTrace:  false,
+	StackTraceHandler: defaultStackTraceHandler,
 }
 
 // Helper function to set default values
@@ -27,5 +41,9 @@ func configDefault(config ...Config) Config {
 	// Override default config
 	cfg := config[0]
 
+	if cfg.EnableStackTrace && cfg.StackTraceHandler == nil {
+		cfg.StackTraceHandler = defaultStackTraceHandler
+	}
+
 	return cfg
 }

middleware/recover/recover.go

@@ -2,10 +2,18 @@ package recover
 
 import (
 	"fmt"
+	"os"
+	"runtime"
 
 	"github.com/gofiber/fiber/v2"
 )
 
+func defaultStackTraceHandler(e interface{}) {
+	buf := make([]byte, defaultStackTraceBufLen)
+	buf = buf[:runtime.Stack(buf, false)]
+	_, _ = os.Stderr.WriteString(fmt.Sprintf("panic: %v\n%s\n", e, buf))
+}
+
 // New creates a new middleware handler
 func New(config ...Config) fiber.Handler {
 	// Set default config
@@ -21,6 +29,10 @@ func New(config ...Config) fiber.Handler {
 		// Catch panics
 		defer func() {
 			if r := recover(); r != nil {
+				if cfg.EnableStackTrace {
+					cfg.StackTraceHandler(r)
+				}
+
 				var ok bool
 				if err, ok = r.(error); !ok {
 					// Set error that will call the global error handler

middleware/recover/recover_test.go

@@ -41,3 +41,18 @@ func Test_Recover_Next(t *testing.T) {
 	utils.AssertEqual(t, nil, err)
 	utils.AssertEqual(t, fiber.StatusNotFound, resp.StatusCode)
 }
+
+func Test_Recover_EnableStackTrace(t *testing.T) {
+	app := fiber.New()
+	app.Use(New(Config{
+		EnableStackTrace: true,
+	}))
+
+	app.Get("/panic", func(c *fiber.Ctx) error {
+		panic("Hi, I'm an error!")
+	})
+
+	resp, err := app.Test(httptest.NewRequest("GET", "/panic", nil))
+	utils.AssertEqual(t, nil, err)
+	utils.AssertEqual(t, fiber.StatusInternalServerError, resp.StatusCode)
+}