Add IsExternalStorageError to check for external storage errors. (#458)

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## [master](https://github.com/arangodb/go-driver/tree/master) (N/A)
 - Use Go 1.19.4
+- Add `IsExternalStorageError` to check for [external storage errors](https://www.arangodb.com/docs/stable/appendix-error-codes.html#external-arangodb-storage-errors).
 
 ## [1.4.1](https://github.com/arangodb/go-driver/tree/v1.4.1) (2022-12-14)
 - Add support for `checksum` in Collections

error.go

@@ -44,6 +44,13 @@ const (
 	// Internal ArangoDB storage errors
 	ErrArangoReadOnly = 1004
 
+	// External ArangoDB storage errors
+	ErrArangoCorruptedDatafile    = 1100
+	ErrArangoIllegalParameterFile = 1101
+	ErrArangoCorruptedCollection  = 1102
+	ErrArangoFileSystemFull       = 1104
+	ErrArangoDataDirLocked        = 1107
+
 	// General ArangoDB storage errors
 	ErrArangoConflict                 = 1200
 	ErrArangoDocumentNotFound         = 1202
@@ -167,6 +174,18 @@ func IsDataSourceOrDocumentNotFound(err error) bool {
 		IsArangoErrorWithErrorNum(err, ErrArangoDocumentNotFound, ErrArangoDataSourceNotFound)
 }
 
+// IsExternalStorageError returns true if ArangoDB is having an error with accessing or writing to storage.
+func IsExternalStorageError(err error) bool {
+	return IsArangoErrorWithErrorNum(
+		err,
+		ErrArangoCorruptedDatafile,
+		ErrArangoIllegalParameterFile,
+		ErrArangoCorruptedCollection,
+		ErrArangoFileSystemFull,
+		ErrArangoDataDirLocked,
+	)
+}
+
 // IsConflict returns true if the given error is an ArangoError with code 409, indicating a conflict.
 func IsConflict(err error) bool {
 	return IsArangoErrorWithCode(err, http.StatusConflict) || IsArangoErrorWithErrorNum(err, ErrUserDuplicate)