From 5a960fcc7751ce42fa5ca334e493c18d232a8e5c Mon Sep 17 00:00:00 2001
From: marcellaantania <marcellaantaniatan@gmail.com>
Date: Thu, 12 Oct 2023 01:43:23 +0800
Subject: [PATCH] Throw error message when list command format is invalid

---
 src/main/java/seedu/address/logic/Messages.java          | 6 ++++++
 .../seedu/address/logic/parser/ListCommandParser.java    | 9 ++++++++-
 .../address/logic/parser/AddressBookParserTest.java      | 6 +++---
 3 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/src/main/java/seedu/address/logic/Messages.java b/src/main/java/seedu/address/logic/Messages.java
index 60154600561..b4336e7c7bc 100644
--- a/src/main/java/seedu/address/logic/Messages.java
+++ b/src/main/java/seedu/address/logic/Messages.java
@@ -22,6 +22,12 @@ public class Messages {
             + "the funds the Employee currently has!";
     public static final String MESSAGE_EMPTY_DEPARTMENT_FILTER = "department name cannot be empty!";
 
+    public static final String MESSAGE_LIST_COMMAND_FORMAT = "list: Lists all the details of an organization’s employees, "
+            + "or list all employees of a specified department (case-insensitive).\n"
+            + "Parameters: [d/DEPARTMENT] (optional)\n"
+            + "Example: list (to list all employees) or "
+            + "list d/Engineering (to list all employees in Engineering department)";
+
     public static final String MESSAGE_LIST_SUCCESS = "Listed all employees (%1$d)";
 
     public static final String MESSAGE_FILTER_SUCCESS = "Listed filtered employees (%1$d)";
diff --git a/src/main/java/seedu/address/logic/parser/ListCommandParser.java b/src/main/java/seedu/address/logic/parser/ListCommandParser.java
index 45968f02c7d..b56b4fbf1ac 100644
--- a/src/main/java/seedu/address/logic/parser/ListCommandParser.java
+++ b/src/main/java/seedu/address/logic/parser/ListCommandParser.java
@@ -26,8 +26,15 @@ public ListCommand parse(String args) throws ParseException {
         requireNonNull(args);
         ArgumentMultimap argMultimap =
                 ArgumentTokenizer.tokenize(args, PREFIX_DEPARTMENT);
+
         if (argMultimap.getValue(PREFIX_DEPARTMENT).isEmpty()) {
-            return new ListCommand();
+            try {
+                String secondArg = args.split(" ")[1];
+                throw new ParseException(String.format(Messages.MESSAGE_INVALID_COMMAND_FORMAT,
+                        Messages.MESSAGE_LIST_COMMAND_FORMAT));
+            } catch (IndexOutOfBoundsException e) {
+                return new ListCommand();
+            }
         }
         try {
             Department filteringDepartment = new Department(argMultimap.getValue(PREFIX_DEPARTMENT).get());
diff --git a/src/test/java/seedu/address/logic/parser/AddressBookParserTest.java b/src/test/java/seedu/address/logic/parser/AddressBookParserTest.java
index 5a1ab3dbc0c..46c09c9f742 100644
--- a/src/test/java/seedu/address/logic/parser/AddressBookParserTest.java
+++ b/src/test/java/seedu/address/logic/parser/AddressBookParserTest.java
@@ -2,8 +2,7 @@
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertTrue;
-import static seedu.address.logic.Messages.MESSAGE_INVALID_COMMAND_FORMAT;
-import static seedu.address.logic.Messages.MESSAGE_UNKNOWN_COMMAND;
+import static seedu.address.logic.Messages.*;
 import static seedu.address.testutil.Assert.assertThrows;
 import static seedu.address.testutil.TypicalIndexes.INDEX_FIRST_PERSON;
 
@@ -85,7 +84,8 @@ public void parseCommand_help() throws Exception {
     @Test
     public void parseCommand_list() throws Exception {
         assertTrue(parser.parseCommand(ListCommand.COMMAND_WORD) instanceof ListCommand);
-        assertTrue(parser.parseCommand(ListCommand.COMMAND_WORD + " 3") instanceof ListCommand);
+        assertThrows(ParseException.class, String.format(MESSAGE_INVALID_COMMAND_FORMAT, MESSAGE_LIST_COMMAND_FORMAT), ()
+                -> parser.parseCommand(ListCommand.COMMAND_WORD + " 3"));
     }
 
     @Test