This PR is to add comments to TestAlluxioFIlUtils_CleanCache in pkg/ddc/alluxio/operations/cached_test.go

pkg/ddc/alluxio/operations/cached_test.go

@@ -51,6 +51,18 @@ func TestAlluxioFileUtils_CachedState(t *testing.T) {
 	}
 }
 
+// TestAlluxioFIlUtils_CleanCache tests the CleanCache function of AlluxioFileUtils.
+// It uses gomonkey to mock the exec function and simulates different scenarios, including command execution failure and successful execution on both Ubuntu and Alpine systems.
+// The test checks if the CleanCache function correctly handles errors and returns the expected results based on the mocked exec function's output.
+// The test cases include:
+// 1. Simulating a command execution failure and verifying that the CleanCache function returns an error.
+// 2. Simulating a successful command execution on an Ubuntu system and verifying that the CleanCache function returns nil (indicating success).
+// 3. Simulating a successful command execution on an Alpine system and verifying that the CleanCache function returns nil (indicating success).
+
+// parameters:
+// - t: The testing object used to report test failures and log information during the test execution.
+// returns:
+// - None. The function uses the testing object to report results and does not return any value.
 func TestAlluxioFIlUtils_CleanCache(t *testing.T) {
 	ExecCommonUbuntu := func(a AlluxioFileUtils, command []string, verbose bool) (stdout string, stderr string, err error) {
 		return "Ubuntu", "", nil