transportAuth(): Add checks for invalid transports

Update GitRepositoryReconciler to use a nil authOpts unless it's
configured.

Signed-off-by: Sunny <darkowlzz@protonmail.com>

controllers/gitrepository_controller.go

@@ -230,7 +230,7 @@ func (r *GitRepositoryReconciler) reconcile(ctx context.Context, repository sour
 	defer os.RemoveAll(tmpGit)
 
 	// Configure auth options using secret
-	authOpts := &git.AuthOptions{}
+	var authOpts *git.AuthOptions
 	if repository.Spec.SecretRef != nil {
 		name := types.NamespacedName{
 			Namespace: repository.GetNamespace(),

pkg/git/gogit/transport.go

@@ -17,6 +17,8 @@ limitations under the License.
 package gogit
 
 import (
+	"fmt"
+
 	"github.com/go-git/go-git/v5/plumbing/transport"
 	"github.com/go-git/go-git/v5/plumbing/transport/http"
 	"github.com/go-git/go-git/v5/plumbing/transport/ssh"
@@ -53,6 +55,10 @@ func transportAuth(opts *git.AuthOptions) (transport.AuthMethod, error) {
 			}
 			return pk, nil
 		}
+	case "":
+		return nil, fmt.Errorf("no transport type set")
+	default:
+		return nil, fmt.Errorf("unknown transport '%s'", opts.Transport)
 	}
 	return nil, nil
 }

pkg/git/gogit/transport_test.go

@@ -170,10 +170,14 @@ func Test_transportAuth(t *testing.T) {
 		{
 			name:    "Empty",
 			opts:    &git.AuthOptions{},
-			wantFunc: func(g *WithT, t transport.AuthMethod, opts *git.AuthOptions) {
-				g.Expect(t).To(BeNil())
+			wantErr: errors.New("no transport type set"),
 		},
-			wantErr: nil,
+		{
+			name: "Unknown transport",
+			opts: &git.AuthOptions{
+				Transport: "foo",
+			},
+			wantErr: errors.New("unknown transport 'foo'"),
 		},
 	}
 	for _, tt := range tests {