Merge pull request #197 from ReflectiveObsidian/improve-delete-behaviour

Improve delete behaviour

src/main/java/seedu/address/logic/Messages.java

@@ -20,7 +20,8 @@ public class Messages {
     public static final String MESSAGE_DUPLICATE_FIELDS =
                 "Multiple values specified for the following single-valued field(s): ";
 
-    public static final String MESSAGE_INVALID_PERSON_UUID = "The UUID provided is invalid: ";
+    public static final String MESSAGE_INVALID_PERSON_UUID = "The UUID provided is invalid, "
+            + "does the person exist and is it 4 characters long? The UUID you entered was: ";
     public static final String MESSAGE_MISSING_ATTRIBUTES = "Missing attributes to delete.";
 
     public static final String MESSAGE_INVALID_PREDEFINED_RELATIONSHIP_DESCRIPTOR = "You cannot delete this "
@@ -44,6 +45,8 @@ public class Messages {
 
     public static final String MESSAGE_SEARCH_FAILURE = "No Relationship pathway found";
     public static final String MESSAGE_INVALID_ATTRIBUTE_FORMAT = "Invalid attribute format.";
+    public static final String MESSAGE_UUID_EMPTY = "Blank UUID provided. Please provide a valid UUID in this format: "
+             + "/UUID" + "\nExample: /d8d8";
     public static final String MESSAGE_INVALID_UUID_FORMAT = "Invalid UUID format. Please ensure that the UUID is "
             + "in the format: /<UUID>.";
 

src/main/java/seedu/address/logic/commands/DeleteCommand.java

@@ -21,8 +21,8 @@ public class DeleteCommand extends Command {
 
     public static final String MESSAGE_USAGE = COMMAND_WORD
             + ": Deletes the person identified by the index number used in the displayed person list.\n"
-            + "Parameters: INDEX (must be a positive integer)\n"
-            + "Example: " + COMMAND_WORD + " 1234";
+            + "Parameters: UUID (must be from a person who exists, 4 characters)\n"
+            + "Example: " + COMMAND_WORD + " /1bd4";
 
     public static final String MESSAGE_DELETE_PERSON_SUCCESS = "Deleted Person: %1$s";
 
@@ -38,7 +38,10 @@ public CommandResult execute(Model model) throws CommandException {
         UUID targetUuid = model.getFullUuid(target);
 
         if (targetUuid == null) {
-            throw new CommandException(Messages.MESSAGE_INVALID_PERSON_UUID);
+            if (target.isEmpty()) {
+                throw new CommandException(Messages.MESSAGE_UUID_EMPTY + "\n" + MESSAGE_USAGE);
+            }
+            throw new CommandException(Messages.MESSAGE_INVALID_PERSON_UUID + target + "\n" + MESSAGE_USAGE);
         }
 
         Person personToDelete = model.getPersonByUuid(targetUuid);

src/main/java/seedu/address/logic/parser/DeleteCommandParser.java

@@ -16,8 +16,8 @@ public class DeleteCommandParser implements Parser<DeleteCommand> {
      */
     public DeleteCommand parse(String args) throws ParseException {
         if (!args.trim().startsWith("/")) {
-            throw new ParseException("Input a UUID prefixed with '/'.");
+            throw new ParseException("Please input a UUID prefixed with '/'." + "\n" + DeleteCommand.MESSAGE_USAGE);
         }
-        return new DeleteCommand(args.trim().substring(1));
+        return new DeleteCommand(args.trim().substring(1).trim());
     }
 }

src/test/java/seedu/address/logic/LogicManagerTest.java

@@ -21,6 +21,7 @@
 
 import seedu.address.logic.commands.AddCommand;
 import seedu.address.logic.commands.CommandResult;
+import seedu.address.logic.commands.DeleteCommand;
 import seedu.address.logic.commands.ListCommand;
 import seedu.address.logic.commands.exceptions.CommandException;
 import seedu.address.logic.parser.exceptions.ParseException;
@@ -62,7 +63,10 @@ public void execute_invalidCommandFormat_throwsParseException() {
     @Test
     public void execute_commandExecutionError_throwsCommandException() {
         String deleteCommand = "delete /9";
-        assertCommandException(deleteCommand, MESSAGE_INVALID_PERSON_UUID);
+        assertCommandException(
+                deleteCommand,
+                MESSAGE_INVALID_PERSON_UUID + "9" + "\n" + DeleteCommand.MESSAGE_USAGE
+        );
     }
 
     @Test

src/test/java/seedu/address/logic/commands/DeleteCommandTest.java

@@ -55,7 +55,11 @@ public void execute_validUuid_success() {
     public void execute_nonRealUuidFilteredList_throwsCommandException() {
         DeleteCommand deleteCommand = new DeleteCommand("12345");
 
-        assertCommandFailure(deleteCommand, model, Messages.MESSAGE_INVALID_PERSON_UUID);
+        assertCommandFailure(
+                deleteCommand,
+                model,
+                Messages.MESSAGE_INVALID_PERSON_UUID + "12345" + "\n" + DeleteCommand.MESSAGE_USAGE
+        );
     }
 
     @Test
@@ -113,4 +117,15 @@ public void execute_validUuidUnfilteredList_success() {
 
         assertCommandSuccess(deleteCommand, model, expectedMessage, expectedModel);
     }
+    @Test
+    public void execute_blankUuid_error() {
+        DeleteCommand deleteCommand = new DeleteCommand("");
+        String expectedMessage = Messages.MESSAGE_UUID_EMPTY + "\n" + DeleteCommand.MESSAGE_USAGE;
+        ModelManager emptyModel = new ModelManager(model.getAddressBook(), new UserPrefs());
+        try {
+            deleteCommand.execute(emptyModel);
+        } catch (CommandException e) {
+            assertEquals(expectedMessage, e.getMessage());
+        }
+    }
 }