Added HandleError flag to the middleware config to enable/disable err…

…or propagation (#22)

README.md

@@ -142,6 +142,17 @@ e.Use(lecho.Middleware(lecho.Config{
     // Output: {"level":"info","user_id":"123", ...}
 ```
 
+### Errors
+Since lecho v3.4.0, the middleware does not automatically propagate errors up the chain. 
+If you want to do that, you can set `HandleError` to ``true``.
+
+```go
+e.Use(lecho.Middleware(lecho.Config{
+    Logger: logger,
+    HandleError: true,
+}))
+```
+
 ## Helpers
 
 ### Level converters

middleware.go

@@ -29,6 +29,8 @@ type (
 		RequestIDKey string
 		// NestKey is the key name to use for the nested logger in a log record.
 		NestKey string
+		// HandleError indicates whether to propagate errors up the middleware chain, so the global error handler can decide appropriate status code.
+		HandleError bool
 	}
 
 	// Enricher is a function that can be used to enrich the logger with additional information.
@@ -117,7 +119,12 @@ func Middleware(config Config) echo.MiddlewareFunc {
 				config.BeforeNext(c)
 			}
 
-			err = next(c)
+			if err = next(c); err != nil {
+				if config.HandleError {
+					c.Error(err)
+				}
+			}
+
 			stop := time.Now()
 
 			var mainEvt *zerolog.Event

middleware_test.go

@@ -14,7 +14,7 @@ import (
 )
 
 func TestMiddleware(t *testing.T) {
-	t.Run("should not trigger error handler", func(t *testing.T) {
+	t.Run("should not trigger error handler when HandleError is false", func(t *testing.T) {
 		var called bool
 		e := echo.New()
 		e.HTTPErrorHandler = func(err error, c echo.Context) {
@@ -40,6 +40,34 @@ func TestMiddleware(t *testing.T) {
 		assert.False(t, called, "should not call error handler")
 	})
 
+	t.Run("should trigger error handler when HandleError is true", func(t *testing.T) {
+		var called bool
+		e := echo.New()
+		e.HTTPErrorHandler = func(err error, c echo.Context) {
+			called = true
+
+			c.JSON(http.StatusInternalServerError, err.Error())
+		}
+		req := httptest.NewRequest(http.MethodGet, "/", nil)
+		req.Header.Set(echo.HeaderContentType, echo.MIMEApplicationJSON)
+		rec := httptest.NewRecorder()
+		c := e.NewContext(req, rec)
+
+		m := lecho.Middleware(lecho.Config{
+			HandleError: true,
+		})
+
+		next := func(c echo.Context) error {
+			return errors.New("error")
+		}
+
+		handler := m(next)
+		err := handler(c)
+
+		assert.Error(t, err, "should return error")
+		assert.Truef(t, called, "should call error handler")
+	})
+
 	t.Run("should use enricher", func(t *testing.T) {
 		e := echo.New()
 		req := httptest.NewRequest(http.MethodGet, "/", nil)