Adding more testcases.

components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/operation/mgt/OperationManagerImpl.java

@@ -344,18 +344,22 @@ public class OperationManagerImpl implements OperationManager {
         PaginationResult paginationResult = null;
         List<Operation> operations = new ArrayList<>();
         String owner = request.getOwner();
+        try {
+            if (!DeviceManagerUtil.isDeviceExists(deviceId)) {
+                throw new OperationManagementException("Device not found for given device " +
+                        "Identifier:" + deviceId.getId() + " and given type : " +
+                        deviceId.getType());
+            }
+        } catch (DeviceManagementException e) {
+            throw new OperationManagementException("Error while checking the existence of the device identifier - "
+                    + deviceId.getId() + " of the device type - " + deviceId.getType(), e);
+        }
         if (!isActionAuthorized(deviceId)) {
             throw new OperationManagementException("User '" + getUser() + "' is not authorized to access the '" +
                     deviceId.getType() + "' device, which carries the identifier '" +
                     deviceId.getId() + "' of owner '" + owner + "'");
         }
-
         EnrolmentInfo enrolmentInfo = this.getEnrolmentInfo(deviceId, owner);
-        if (enrolmentInfo == null) {
-            throw new OperationManagementException("Device not found for given device " +
-                    "Identifier:" + deviceId.getId() + " and given type" +
-                    deviceId.getType());
-        }
         int enrolmentId = enrolmentInfo.getId();
         try {
             OperationManagementDAOFactory.openConnection();

components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/util/DeviceManagerUtil.java

@@ -474,6 +474,13 @@ public final class DeviceManagerUtil {
         return true;
     }
 
+    public static boolean isDeviceExists(DeviceIdentifier deviceIdentifier) throws DeviceManagementException {
+        Device device = DeviceManagementDataHolder.getInstance().getDeviceManagementProvider().getDevice(deviceIdentifier,
+                false);
+        return !(device == null || device.getDeviceIdentifier() == null ||
+                device.getDeviceIdentifier().isEmpty() || device.getEnrolmentInfo() == null);
+    }
+
     private static CacheManager getCacheManager() {
         return Caching.getCacheManagerFactory().getCacheManager(DeviceManagementConstants.DM_CACHE_MANAGER);
     }

components/device-mgt/org.wso2.carbon.device.mgt.core/src/test/java/org/wso2/carbon/device/mgt/core/operation/OperationManagementTests.java

@@ -68,6 +68,7 @@ public class OperationManagementTests extends BaseDeviceManagementTest {
     private static final int NO_OF_DEVICES = 5;
     private static final String ADMIN_USER = "admin";
     private static final String NON_ADMIN_USER = "test";
+    private static final String INVALID_DEVICE = "ThisIsInvalid";
 
     private List<DeviceIdentifier> deviceIds = new ArrayList<>();
     private OperationManager operationMgtService;
@@ -113,7 +114,7 @@ public class OperationManagementTests extends BaseDeviceManagementTest {
         try {
             ArrayList<DeviceIdentifier> invalidDevices = new ArrayList<>();
             for (int i = 0; i < 3; i++) {
-                invalidDevices.add(new DeviceIdentifier("12345" + i, DEVICE_TYPE));
+                invalidDevices.add(new DeviceIdentifier(INVALID_DEVICE + i, DEVICE_TYPE));
             }
             invalidDevices.addAll(this.deviceIds);
             Activity activity = this.operationMgtService.addOperation(getOperation(new CommandOperation(),
@@ -461,4 +462,27 @@ public class OperationManagementTests extends BaseDeviceManagementTest {
         Assert.assertTrue(operations == null);
     }
 
+    @Test(dependsOnMethods = "getOperationForInactiveDevice", expectedExceptions = OperationManagementException.class)
+    public void getPaginatedOperationDeviceForInvalidDevice() throws DeviceManagementException, OperationManagementException {
+        PrivilegedCarbonContext.startTenantFlow();
+        PrivilegedCarbonContext.getThreadLocalCarbonContext().setTenantId(MultitenantConstants.SUPER_TENANT_ID, true);
+        PrivilegedCarbonContext.getThreadLocalCarbonContext().setUsername(ADMIN_USER);
+        try {
+            PaginationRequest request = new PaginationRequest(1, 2);
+            request.setDeviceType(DEVICE_TYPE);
+            request.setOwner(ADMIN_USER);
+            PaginationResult result = this.operationMgtService.getOperations(new DeviceIdentifier(INVALID_DEVICE, DEVICE_TYPE), request);
+            Assert.assertEquals(result.getRecordsFiltered(), 4);
+            Assert.assertEquals(result.getData().size(), 2);
+            Assert.assertEquals(result.getRecordsTotal(), 4);
+        } finally {
+            PrivilegedCarbonContext.endTenantFlow();
+        }
+    }
+
+    @Test(dependsOnMethods = "getOperationForInactiveDevice", expectedExceptions = OperationManagementException.class)
+    public void getPendingOperationDeviceForInvalidDevice() throws DeviceManagementException, OperationManagementException {
+       this.operationMgtService.getPendingOperations(new DeviceIdentifier(INVALID_DEVICE, DEVICE_TYPE));
+    }
+
 }