Add comments to TestUpdateDatasetStatus on pkg\ddc\jindo\dataset_test.go (#4669)

Signed-off-by: chole <11876014+chole_1@user.noreply.gitee.com>
Co-authored-by: chole <11876014+chole_1@user.noreply.gitee.com>

Author: chole-del

pkg/ddc/jindo/dataset_test.go

@@ -116,6 +116,24 @@ func TestUpdateCacheOfDataset(t *testing.T) {
 	}
 }
 
+// TestUpdateDatasetStatus tests the UpdateDatasetStatus method of JindoEngine to ensure correct
+// dataset status updates under various phases. It validates:
+// 1. Phase transitions (Bound, Failed, None)
+// 2. Preservation of HCFS status fields during updates
+// 3. Proper synchronization of cache states from runtime status
+//
+// Test strategy:
+// - Creates mock Dataset and JindoRuntime objects in a test namespace
+// - Uses a fake Kubernetes client to simulate API server interactions
+// - Verifies three key aspects of DatasetStatus after updates:
+//   a) Phase matches expected state
+//   b) CacheStates are properly propagated from runtime status
+//   c) HCFSStatus fields remain unchanged during phase transitions
+//
+// Test cases cover:
+// - Successful bound state update
+// - Failure state handling
+// - Default/none state transition
 func TestUpdateDatasetStatus(t *testing.T) {
 	testDatasetInputs := []*datav1alpha1.Dataset{
 		{