Fix secret syntax

.vscode/launch.json

@@ -8,7 +8,7 @@
       "mode": "debug",
       "buildFlags": "-tags 'netgo osusergo'",
       "program": "${workspaceRoot}/cmd/pipeline-convert/",
-      "args": ["-s", "drone/testdata/simple.yml", "-d", "output/"],
+      "args": ["-s", "drone/testdata/.drone.yml", "-d", "output/"],
       "cwd": "${workspaceFolder}",
     }
   ]

drone/drone_test.go

@@ -25,7 +25,7 @@ func getPipelineByName(pipelines []*transform.Pipeline, name string) *transform.
 }
 
 func TestTransformSimple(t *testing.T) {
-	buf, err := os.ReadFile("testdata/simple.yml")
+	buf, err := os.ReadFile("testdata/.drone.yml")
 	require.NoError(t, err)
 
 	d := drone.New()

secrets.go

@@ -16,13 +16,13 @@ type Secrets []Secret
 func (s Secrets) MarshalYAML() (interface{}, error) {
 	arr := make([]interface{}, 0, len(s))
 	for _, secret := range s {
-		if secret.Target == "" || strings.EqualFold(secret.Source, secret.Target) {
+		if secret.Target != "" && !strings.EqualFold(secret.Source, secret.Target) {
 			arr = append(arr, Secret{
 				Source: secret.Source,
 				Target: strings.ToLower(secret.Target),
 			})
 		} else {
-			arr = append(arr, secret)
+			arr = append(arr, secret.Source)
 		}
 	}
 	return arr, nil