update requiredFlagsErr interface, errRequiredFlags struct and associated functions to handle map

context.go

@@ -289,23 +289,34 @@ func normalizeFlags(flags []Flag, set *flag.FlagSet) error {
 
 type requiredFlagsErr interface {
 	error
-	getMissingFlags() []string
+	getMissingFlags() map[string]bool
 }
 
 type errRequiredFlags struct {
-	missingFlags []string
+	missingFlags map[string]bool
 }
 
 func (e *errRequiredFlags) Error() string {
-	numberOfMissingFlags := len(e.missingFlags)
+	var missingFlagNames []string
+	var missingFlagNamesReqErr []string
+
+	for k, v := range e.missingFlags {
+		if v == false {
+			missingFlagNames = append(missingFlagNames, k)
+		} else {
+			missingFlagNamesReqErr = append(missingFlagNamesReqErr, k)
+		}
+	}
+
+	numberOfMissingFlags := len(missingFlagNames)
 	if numberOfMissingFlags == 1 {
-		return fmt.Sprintf("Required flag %q not set", e.missingFlags[0])
+		return fmt.Sprintf("Required flag %q not set", missingFlagNames[0])
 	}
-	joinedMissingFlags := strings.Join(e.missingFlags, ", ")
+	joinedMissingFlags := strings.Join(missingFlagNames, ", ")
 	return fmt.Sprintf("Required flags %q not set", joinedMissingFlags)
 }
 
-func (e *errRequiredFlags) getMissingFlags() []string {
+func (e *errRequiredFlags) getMissingFlags() map[string]bool {
 	return e.missingFlags
 }