graph/education: Fix issues reported by sonarcloud

services/graph/pkg/service/v0/errorcode/errorcode.go

@@ -1,3 +1,4 @@
+// Package errorcode allows to deal with graph error codes
 package errorcode
 
 import (
@@ -13,6 +14,7 @@ import (
 // ErrorCode defines code as used in MS Graph - see https://docs.microsoft.com/en-us/graph/errors?context=graph%2Fapi%2F1.0&view=graph-rest-1.0
 type ErrorCode int
 
+// Error defines a custom error struct, containing and MS Graph error code an a textual error message
 type Error struct {
 	errorCode ErrorCode
 	msg       string
@@ -79,6 +81,7 @@ var errorCodes = [...]string{
 	"preconditionFailed",
 }
 
+// New constructs a new errorcode.Error
 func New(e ErrorCode, msg string) Error {
 	return Error{
 		errorCode: e,
@@ -86,7 +89,7 @@ func New(e ErrorCode, msg string) Error {
 	}
 }
 
-// Render writes an Graph ErrorObject to the response writer
+// Render writes an Graph ErrorCode	object to the response writer
 func (e ErrorCode) Render(w http.ResponseWriter, r *http.Request, status int, msg string) {
 	innererror := map[string]interface{}{
 		"date": time.Now().UTC().Format(time.RFC3339),
@@ -104,12 +107,14 @@ func (e ErrorCode) Render(w http.ResponseWriter, r *http.Request, status int, ms
 	render.JSON(w, r, resp)
 }
 
+// Render writes an Graph Error object to the response writer
 func (e Error) Render(w http.ResponseWriter, r *http.Request) {
 	var status int
 	switch e.errorCode {
 	case AccessDenied:
 		status = http.StatusForbidden
-	case InvalidRange:
+	case
+		InvalidRange:
 		status = http.StatusRequestedRangeNotSatisfiable
 	case InvalidRequest:
 		status = http.StatusBadRequest
@@ -125,10 +130,12 @@ func (e Error) Render(w http.ResponseWriter, r *http.Request) {
 	e.errorCode.Render(w, r, status, e.msg)
 }
 
+// String returns the string corresponding to the ErrorCode
 func (e ErrorCode) String() string {
 	return errorCodes[e]
 }
 
+// Error return the concatenation of the error string and optinal message
 func (e Error) Error() string {
 	errString := errorCodes[e.errorCode]
 	if e.msg != "" {