fix npd for incompatible sources on json legacy output (#623)

Author: dustin-decker

pkg/output/legacy_json.go

@@ -19,13 +19,27 @@ import (
 )
 
 func PrintLegacyJSON(r *detectors.ResultWithMetadata) {
-	repoPath, remote, err := git.PrepareRepo(r.SourceMetadata.GetGithub().Repository)
+	var repo string
+	switch r.SourceType {
+	case sourcespb.SourceType_SOURCE_TYPE_GIT:
+		repo = r.SourceMetadata.GetGit().Repository
+	case sourcespb.SourceType_SOURCE_TYPE_GITHUB:
+		repo = r.SourceMetadata.GetGithub().Repository
+	case sourcespb.SourceType_SOURCE_TYPE_GITLAB:
+		repo = r.SourceMetadata.GetGitlab().Repository
+	default:
+		logrus.Errorf("unsupported source type for legacy json output: %s", r.SourceType)
+	}
+
+	// cloning the repo again here is not great and only works with unauthed repos
+	repoPath, remote, err := git.PrepareRepo(repo)
 	if err != nil || repoPath == "" {
 		logrus.WithError(err).Fatal("error preparing git repo for scanning")
 	}
 	if remote {
 		defer os.RemoveAll(repoPath)
 	}
+
 	legacy := ConvertToLegacyJSON(r, repoPath)
 	out, err := json.Marshal(legacy)
 	if err != nil {