special case handling: if one file has been sent and it is empty, return a correct invalid HTTP code AND remove the resource folder

internal/app/xhttp/middleware.go

@@ -34,9 +34,10 @@ func contextMiddleware(config conf.Config, processes ...pm2.Process) echo.Middle
 			// if the endpoint is not for healthcheck, create a
 			// Resource.
 			if err := ctx.WithResource(trace); err != nil {
-				// required to have a correct status code.
+				err = doCleanup(ctx, err)
-				ctx.Error(err)
+				err = doErr(ctx, err)
 				return ctx.LogRequestResult(err, false)
+
 			}
 			return next(ctx)
 		}
@@ -62,9 +63,30 @@ func loggerMiddleware() echo.MiddlewareFunc {
 func cleanupMiddleware() echo.MiddlewareFunc {
 	return func(next echo.HandlerFunc) echo.HandlerFunc {
 		return func(c echo.Context) error {
-			const op string = "xhttp.cleanupMiddleware"
 			err := next(c)
 			ctx := context.MustCastFromEchoContext(c)
+			return doCleanup(ctx, err)
+		}
+	}
+}
+
+// errorMiddleware handles errors (if any).
+func errorMiddleware() echo.MiddlewareFunc {
+	return func(next echo.HandlerFunc) echo.HandlerFunc {
+		return func(c echo.Context) error {
+			ctx := context.MustCastFromEchoContext(c)
+			err := next(ctx)
+			if err == nil {
+				// so far so good!
+				return nil
+			}
+			return doErr(ctx, err)
+		}
+	}
+}
+
+func doCleanup(ctx context.Context, err error) error {
+	const op string = "xhttp.cleanup"
 	if !ctx.HasResource() {
 		// nothing to remove.
 		return err
@@ -83,20 +105,9 @@ func cleanupMiddleware() echo.MiddlewareFunc {
 		ctx.XLogger().ErrorOp(xerror.Op(xerr), xerr)
 	}
 	return err
-		}
-	}
 }
 
-// errorMiddleware handles errors (if any).
+func doErr(ctx context.Context, err error) error {
-func errorMiddleware() echo.MiddlewareFunc {
-	return func(next echo.HandlerFunc) echo.HandlerFunc {
-		return func(c echo.Context) error {
-			ctx := context.MustCastFromEchoContext(c)
-			err := next(ctx)
-			if err == nil {
-				// so far so good!
-				return nil
-			}
 	// if it's an error from echo
 	// like 404 not found and so on.
 	if echoHTTPErr, ok := err.(*echo.HTTPError); ok {
@@ -122,6 +133,4 @@ func errorMiddleware() echo.MiddlewareFunc {
 	// required to have a correct status code.
 	ctx.Error(httpErr)
 	return httpErr
-		}
-	}
 }

internal/app/xhttp/pkg/context/context.go

@@ -2,9 +2,11 @@ package context
 
 import (
 	"fmt"
+	"io"
 	"net/http"
 	"reflect"
 	"strconv"
+	"strings"
 	"time"
 
 	"github.com/labstack/echo/v4"
@@ -102,6 +104,14 @@ func (ctx *Context) WithResource(directoryName string) error {
 		// write form files from request.
 		form, err := ctx.MultipartForm()
 		if err != nil {
+			/*
+				(very) special case: one and
+				only one file has been sent
+				and it is empty.
+			*/
+			if strings.Contains(err.Error(), io.EOF.Error()) {
+				return r, xerror.Invalid(op, "one file has been sent but it is empty: does it exist?", err)
+			}
 			return r, err
 		}
 		for _, files := range form.File {