Add LogLevelSetter to recover middleware

Author: ant1k9

middleware/recover.go

@@ -9,6 +9,9 @@ import (
 )
 
 type (
+	// LogLevelSetter defines a function to get log level for the recovered value.
+	LogLevelSetter func(value interface{}) log.Lvl
+
 	// RecoverConfig defines the config for Recover middleware.
 	RecoverConfig struct {
 		// Skipper defines a function to skip middleware.
@@ -30,6 +33,10 @@ type (
 		// LogLevel is log level to printing stack trace.
 		// Optional. Default value 0 (Print).
 		LogLevel log.Lvl
+
+		// LogLevelSetter defines a function to get log level for the recovered value.
+		// LogLevelSetter has higher priority than LogLevel when it's set.
+		LogLevelSetter LogLevelSetter
 	}
 )
 
@@ -41,6 +48,7 @@ var (
 		DisableStackAll:   false,
 		DisablePrintStack: false,
 		LogLevel:          0,
+		LogLevelSetter:    nil,
 	}
 )
 
@@ -73,11 +81,15 @@ func RecoverWithConfig(config RecoverConfig) echo.MiddlewareFunc {
 					if !ok {
 						err = fmt.Errorf("%v", r)
 					}
+					logLevel := config.LogLevel
+					if config.LogLevelSetter != nil {
+						logLevel = config.LogLevelSetter(r)
+					}
 					stack := make([]byte, config.StackSize)
 					length := runtime.Stack(stack, !config.DisableStackAll)
 					if !config.DisablePrintStack {
 						msg := fmt.Sprintf("[PANIC RECOVER] %v %s\n", err, stack[:length])
-						switch config.LogLevel {
+						switch logLevel {
 						case log.DEBUG:
 							c.Logger().Debug(msg)
 						case log.INFO:

middleware/recover_test.go

@@ -81,3 +81,36 @@ func TestRecoverWithConfig_LogLevel(t *testing.T) {
 		})
 	}
 }
+
+func TestRecoverWithConfig_LogLevelSetter(t *testing.T) {
+	e := echo.New()
+	e.Logger.SetLevel(log.DEBUG)
+
+	buf := new(bytes.Buffer)
+	e.Logger.SetOutput(buf)
+
+	req := httptest.NewRequest(http.MethodGet, "/", nil)
+	rec := httptest.NewRecorder()
+	c := e.NewContext(req, rec)
+
+	config := DefaultRecoverConfig
+	config.LogLevelSetter = func(value interface{}) log.Lvl {
+		if s, ok := value.(string); ok {
+			if s == "test" {
+				return log.DEBUG
+			}
+		}
+		return log.ERROR
+	}
+	h := RecoverWithConfig(config)(echo.HandlerFunc(func(c echo.Context) error {
+		panic("test")
+	}))
+
+	h(c)
+
+	assert.Equal(t, http.StatusInternalServerError, rec.Code)
+
+	output := buf.String()
+	assert.Contains(t, output, "PANIC RECOVER")
+	assert.Contains(t, output, `"level":"DEBUG"`)
+}