Migration v15: No-op migration for schema consistency (#109604)

* migrate to v19

* migrate to v18

* Migration to be verified: v17 Convert minSpan to maxPerRow in panels

* Migration to be verified: 16 Grid layout migration

* Refactor v17 and v19 migrations to use shared helper functions

* Migration to be verified: 15 No-op migration for schema consistency

* Update v27.go

* Update v16.go

* cleanup

---------

Co-authored-by: Haris Rozajac <haris.rozajac12@gmail.com>
Co-authored-by: Haris Rozajac <58232930+harisrozajac@users.noreply.github.com>

apps/dashboard/pkg/migration/schemaversion/migrations.go

@@ -5,7 +5,7 @@ import (
 )
 
 const (
-	MIN_VERSION    = 15
+	MIN_VERSION    = 14
 	LATEST_VERSION = 41
 )
 
@@ -38,6 +38,7 @@ type PanelPluginInfoProvider interface {
 
 func GetMigrations(dsInfoProvider DataSourceInfoProvider, panelProvider PanelPluginInfoProvider) map[int]SchemaVersionMigrationFunc {
 	return map[int]SchemaVersionMigrationFunc{
+		15: V15,
 		16: V16,
 		17: V17,
 		18: V18,

apps/dashboard/pkg/migration/schemaversion/v15.go

@@ -0,0 +1,25 @@
+package schemaversion
+
+// V15 migration is a no-op migration
+// It only updates the schema version to 15
+// It's created to keep the migration history consistent with frontend migrator
+// No specific migration logic is needed between schema version 14 and 15
+
+// Example before migration:
+// {
+//   "schemaVersion": 14,
+//   "title": "My Dashboard",
+//   "panels": [...]
+// }
+
+// Example after migration:
+// {
+//   "schemaVersion": 15,
+//   "title": "My Dashboard",
+//   "panels": [...]
+// }
+
+func V15(dashboard map[string]interface{}) error {
+	dashboard["schemaVersion"] = 15
+	return nil
+}

apps/dashboard/pkg/migration/schemaversion/v15_test.go

@@ -0,0 +1,38 @@
+package schemaversion_test
+
+import (
+	"testing"
+
+	"github.com/grafana/grafana/apps/dashboard/pkg/migration/schemaversion"
+)
+
+func TestV15(t *testing.T) {
+	tests := []migrationTestCase{
+		{
+			name: "v15 no-op migration, updates schema version only",
+			input: map[string]interface{}{
+				"title":         "V15 No-Op Migration Test Dashboard",
+				"schemaVersion": 14,
+				"panels": []interface{}{
+					map[string]interface{}{
+						"type":  "graph",
+						"title": "Panel remains unchanged",
+						"id":    1,
+					},
+				},
+			},
+			expected: map[string]interface{}{
+				"title":         "V15 No-Op Migration Test Dashboard",
+				"schemaVersion": 15,
+				"panels": []interface{}{
+					map[string]interface{}{
+						"type":  "graph",
+						"title": "Panel remains unchanged",
+						"id":    1,
+					},
+				},
+			},
+		},
+	}
+	runMigrationTests(t, tests, schemaversion.V15)
+}