updateref: Convert `NonExistentObjectError` to use error metadata

Convert the `NonExistentObjectError` to use error metadata instead
of embedding the information into the error message.

1 files changed, 10 insertions, 1 deletions

diff --git a/internal/git/updateref/updateref.go b/internal/git/updateref/updateref.go
index 5db4b35fb..3c4815c22 100644
--- a/internal/git/updateref/updateref.go
+++ b/internal/git/updateref/updateref.go
@@ -105,7 +105,16 @@ type NonExistentObjectError struct {
 }
 
 func (e NonExistentObjectError) Error() string {
-	return fmt.Sprintf("pointed reference %q to a non-existent object %q", e.ReferenceName, e.ObjectID)
+	return "target object missing"
+}
+
+// ErrorMetadata implements the `structerr.ErrorMetadater` interface and provides the missing object as well as the
+// reference that should have been updated to point to it.
+func (e NonExistentObjectError) ErrorMetadata() []structerr.MetadataItem {
+	return []structerr.MetadataItem{
+		{Key: "reference", Value: e.ReferenceName},
+		{Key: "missing_object", Value: e.ObjectID},
+	}
 }
 
 // NonCommitObjectError is returned when attempting to point a branch to an object that is not an object.