This PR is to add comments to TestCheckIfRemountRequired(t *testing.T) in pkg\ddc\alluxio\ufs_test.go. (#4895)

* Add comments/notation to TestCheckIfRemountRequired(t *testing.T) in pkg\ddc\alluxio\ufs_test.go.

Signed-off-by: HDZ <1416453048@qq.com>

* fix go fmt issue

Signed-off-by: cheyang <cheyang@163.com>

---------

Signed-off-by: HDZ <1416453048@qq.com>
Signed-off-by: cheyang <cheyang@163.com>
Co-authored-by: cheyang <cheyang@163.com>

Author: HDZsuper

pkg/ddc/alluxio/ufs_test.go

@@ -164,6 +164,7 @@ func TestTotalStorageBytes(t *testing.T) {
 		})
 	}
 }
+
 // TestTotalFileNums validates the AlluxioEngine's ability to correctly retrieve total file numbers from the Alluxio runtime.
 // The test performs the following operations:
 // - Creates mock AlluxioRuntime configurations
@@ -173,7 +174,7 @@ func TestTotalStorageBytes(t *testing.T) {
 // Test Components:
 // - fields: Contains the Alluxio runtime configuration and engine identity
 // - tests: Table-driven test cases with expected values and error conditions
-//!
+// !
 // Flow:
 // 1. Initialize AlluxioEngine with test parameters
 // 2. Mock Kubernetes command execution using function patch
@@ -1010,6 +1011,29 @@ func TestUpdateMountTime(t *testing.T) {
 	}
 }
 
+// TestCheckIfRemountRequired tests the checkIfRemountRequired function in AlluxioEngine.
+// It verifies whether the system correctly identifies when a remount is required based on:
+//   - Runtime's last mount time
+//   - Pod's container start time
+//   - Dataset mount configurations
+//
+// Test cases:
+//  1. When pod started AFTER last mount time (expect remount)
+//     - Runtime mount time: yesterday
+//     - Pod start time: yesterday + 1 day
+//     - Expected: ["/path"] (remount required)
+//  2. When pod started BEFORE last mount time (expect no remount)
+//     - Runtime mount time: yesterday
+//     - Pod start time: yesterday - 1 day
+//     - Expected: [] (no remount needed)
+//
+// The test:
+//   - Creates mock runtime, pod and dataset objects
+//   - Initializes fake Kubernetes client with test objects
+//   - Mocks AlluxioFileUtils operations:
+//   - Always reports Ready() = true
+//   - FindUnmountedAlluxioPaths() returns original paths
+//   - Compares actual remount paths with expected results
 func TestCheckIfRemountRequired(t *testing.T) {
 	yesterday := time.Now().AddDate(0, 0, -1)