Implement search functionality

src/main/java/seedu/binbash/ItemList.java

@@ -2,6 +2,7 @@
 
 import java.util.List;
 import java.util.ArrayList;
+import java.util.stream.Collectors;
 
 public class ItemList {
     private final List<Item> itemList;
@@ -40,17 +41,31 @@ public String deleteItem(int index) {
         return output;
     }
 
+    public String searchItem(String keyword) {
+        ArrayList<Item> filteredList = (ArrayList<Item>) itemList.stream()
+                .filter(item -> item.getItemName().contains(keyword))
+                .collect(Collectors.toList());
+
+        String output = "";
+
+        if (filteredList.isEmpty()) {
+            output += String.format("There are no tasks with the keyword '%s'!", keyword);
+        } else {
+            output = String.format("Here's a list of items that contain the keyword '%s': ", keyword)
+                    + System.lineSeparator()
+                    + printList(filteredList);
+        }
+
+        return output;
+    }
+
     /**
-     * DO LET ME KNOW IF THE METHOD NAME IS WEIRD. IM RETURNING A STRING REPRESENTATION INSTEAD
-     * OF CALLING SOUT TO STAY CONSISTENT WITH THE OTHER COMMANDS BEHAVIOUR. SO IT DOESN'T ACTUALLY
-     * PRINT THE LIST. IF THERES A BETTER NAME LMK THANKS
-     *
      * Returns a string representation of all the items in the list. Each item's string
      * representation is obtained by calling its `toString` method.
      *
      * @return A concatenated string of all item representations in the list, each on a new line.
      */
-    public String printList() {
+    public String printList(List<Item> itemList) {
         String output = "";
 
         for (Item item: itemList) {

src/main/java/seedu/binbash/Parser.java

@@ -2,11 +2,12 @@
 
 import java.util.regex.Matcher;
 
-import seedu.binbash.command.AddCommand;
-import seedu.binbash.command.ByeCommand;
 import seedu.binbash.command.Command;
+import seedu.binbash.command.AddCommand;
 import seedu.binbash.command.DeleteCommand;
+import seedu.binbash.command.SearchCommand;
 import seedu.binbash.command.ListCommand;
+import seedu.binbash.command.ByeCommand;
 
 public class Parser {
     private final ItemList itemList;
@@ -27,13 +28,15 @@ public Command parseCommand(String userInput) {
             return parseDeleteCommand(userInput);
         case "list":
             return parseListCommand(userInput);
+        case "search":
+            return parseSearchCommand(userInput);
         default:
             return new ByeCommand(itemList);
         }
     }
 
-    private Command parseDeleteCommand(String arguments) {
-        Matcher matcher = DeleteCommand.COMMAND_FORMAT.matcher(arguments);
+    private Command parseDeleteCommand(String userInput) {
+        Matcher matcher = DeleteCommand.COMMAND_FORMAT.matcher(userInput);
         if (matcher.matches()) {
             int index = Integer.parseInt(matcher.group("index"));
             return new DeleteCommand(itemList, index);
@@ -42,8 +45,8 @@ private Command parseDeleteCommand(String arguments) {
         }
     }
 
-    private Command parseAddCommand(String arguments) {
-        Matcher matcher = AddCommand.COMMAND_FORMAT.matcher(arguments);
+    private Command parseAddCommand(String userInput) {
+        Matcher matcher = AddCommand.COMMAND_FORMAT.matcher(userInput);
         if (matcher.matches()) {
             String itemName = matcher.group("itemName");
             String itemDescription = matcher.group("itemDescription");
@@ -53,6 +56,16 @@ private Command parseAddCommand(String arguments) {
         }
     }
 
+    private Command parseSearchCommand(String userInput) {
+        Matcher matcher = SearchCommand.COMMAND_FORMAT.matcher(userInput);
+        if (matcher.matches()) {
+            String keyword = matcher.group("keyword");
+            return new SearchCommand(itemList, keyword);
+        } else {
+            return null;
+        }
+    }
+
     private Command parseListCommand(String arguments) {
         return new ListCommand(itemList);
     }

src/main/java/seedu/binbash/command/ListCommand.java

@@ -15,6 +15,6 @@ public ListCommand(ItemList itemList) {
     }
 
     public String execute() {
-        return itemList.printList();
+        return itemList.printList(itemList.getItemList());
     }
 }

src/main/java/seedu/binbash/command/SearchCommand.java

@@ -0,0 +1,23 @@
+package seedu.binbash.command;
+
+import seedu.binbash.ItemList;
+
+import java.util.regex.Pattern;
+
+public class SearchCommand extends Command {
+
+    public static final String COMMAND_STRING = "search";
+    public static final Pattern COMMAND_FORMAT =
+            Pattern.compile("search\\s+(?<keyword>.+?)\\s*$");
+    protected String keyword;
+
+    public SearchCommand(ItemList itemList, String keyword) {
+        super(itemList);
+
+        this.keyword = keyword;
+    }
+
+    public String execute() {
+        return itemList.searchItem(keyword);
+    }
+}

src/test/java/seedu/binbash/ItemListTest.java

@@ -42,7 +42,7 @@ void printList_twoItemsInItemList_correctPrintFormatForBothItems() {
         itemList.addItem("testItem", "1");
         itemList.addItem("testItem", "2");
 
-        String actualOutput = itemList.printList();
+        String actualOutput = itemList.printList(itemList.getItemList());
 
         String expectedOutput = "testItem: 1" + System.lineSeparator() +
                 "testItem: 2" + System.lineSeparator();