Added to echo_service_extensions to handle errors on echo and refacto…

…ring common code blocks

_examples/cmd/echo_service.go

@@ -0,0 +1,38 @@
+package main
+
+import (
+	"github.com/labstack/echo/v4"
+	"github.com/labstack/echo/v4/middleware"
+	"github.com/rozturac/cerror"
+	"github.com/rozturac/cerror/extensions"
+	"net/http"
+)
+
+type EchoErrorResponse struct {
+	Code    string `json:"code"`
+	Message string `json:"message"`
+}
+
+func main() {
+	e := echo.New()
+	e.Use(extensions.AddEchoErrorHandlingMiddlewareWithMapper(func(errorCode, message string, httpStatusCode int) interface{} {
+		return EchoErrorResponse{
+			Code:    errorCode,
+			Message: message,
+		}
+	}))
+
+	e.Use(middleware.CORS())
+
+	e.GET("/example", example)
+
+	e.Start(":8080")
+}
+
+func example(c echo.Context) error {
+	if name := c.Param("Name"); len(name) == 0 {
+		panic(cerror.NullReferenceError("name"))
+	}
+
+	return c.String(http.StatusOK, "Hello, World!")
+}

_examples/cmd/http_service.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"github.com/rozturac/cerror"
+	"github.com/rozturac/cerror/extensions"
 	"net/http"
 )
 
@@ -22,6 +23,6 @@ func main() {
 		}
 	}
 
-	http.Handle("/example", cerror.AddErrorHandlingMiddlewareWithMapper(handler, mapper))
+	http.Handle("/example", extensions.AddHttpErrorHandlingMiddlewareWithMapper(handler, mapper))
 	http.ListenAndServe(":8080", nil)
 }

extensions/common.go

@@ -0,0 +1,24 @@
+package extensions
+
+import (
+	"github.com/rozturac/cerror"
+	"net/http"
+)
+
+type ErrorResponseMapper func(errorCode, message string, httpStatusCode int) interface{}
+
+func getErrorResponseAndStatusCode(candidateError interface{}, mapper ErrorResponseMapper) (interface{}, int) {
+	response := mapper("UnExpectedError", http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+	httpStatusCode := http.StatusInternalServerError
+
+	if err, ok := candidateError.(error); ok {
+		if customError, ok := err.(cerror.Error); ok {
+			response = mapper(customError.ErrorCode(), customError.Error(), customError.HttpStatusCode())
+			httpStatusCode = customError.HttpStatusCode()
+		} else {
+			response = mapper("UnExpectedError", err.Error(), http.StatusInternalServerError)
+		}
+	}
+
+	return response, httpStatusCode
+}

extensions/echo_service_extensions.go

@@ -0,0 +1,32 @@
+package extensions
+
+import (
+	"github.com/labstack/echo/v4"
+	"net/http"
+)
+
+func AddEchoErrorHandlingMiddlewareWithMapper(mapper ErrorResponseMapper) echo.MiddlewareFunc {
+	return func(next echo.HandlerFunc) echo.HandlerFunc {
+		return func(context echo.Context) error {
+			defer func() {
+				if recover := recover(); recover != nil {
+					response, httpStatusCode := getErrorResponseAndStatusCode(recover, mapper)
+					if err := context.JSON(httpStatusCode, response); err != nil {
+						context.NoContent(http.StatusInternalServerError)
+					}
+				} else {
+					context.NoContent(http.StatusInternalServerError)
+				}
+			}()
+
+			if err := next(context); err != nil {
+				response, httpStatusCode := getErrorResponseAndStatusCode(err, mapper)
+				if err := context.JSON(httpStatusCode, response); err != nil {
+					context.NoContent(http.StatusInternalServerError)
+				}
+			}
+
+			return nil
+		}
+	}
+}

extensions/http_service_extensions.go

@@ -0,0 +1,25 @@
+package extensions
+
+import (
+	"encoding/json"
+	"net/http"
+)
+
+func AddHttpErrorHandlingMiddlewareWithMapper(next http.HandlerFunc, mapper ErrorResponseMapper) http.HandlerFunc {
+	return func(writer http.ResponseWriter, request *http.Request) {
+		defer func() {
+			if recover := recover(); recover != nil {
+				response, httpStatusCode := getErrorResponseAndStatusCode(recover, mapper)
+				if buff, err := json.Marshal(response); err != nil {
+					http.Error(writer, err.Error(), http.StatusInternalServerError)
+				} else {
+					http.Error(writer, string(buff), httpStatusCode)
+				}
+			} else {
+				http.Error(writer, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+			}
+		}()
+
+		next(writer, request)
+	}
+}

go.mod

@@ -1,3 +1,5 @@
 module github.com/rozturac/cerror
 
-go 1.16
+go 1.16
+
+require github.com/labstack/echo/v4 v4.6.1 // indirect