Refine search format, add JUnit tests

src/main/java/seedu/address/commons/util/StringUtil.java

@@ -55,14 +55,11 @@ public static boolean containsSubstringIgnoreCase(String sentence, String substr
 
         String preppedSubstring = substring.trim();
         checkArgument(!preppedSubstring.isEmpty(), "Word parameter cannot be empty");
-        checkArgument(preppedSubstring.split("\\s+").length == 1, "Word parameter should be a single word");
 
         String preppedSentence = sentence;
-        String[] wordsInPreppedSentence = preppedSentence.split("\\s+");
 
-        return Arrays.stream(wordsInPreppedSentence)
-                .map(String::toLowerCase)
-                .anyMatch(word -> word.contains(substring.toLowerCase()));
+        return preppedSentence.toLowerCase().contains(substring.toLowerCase());
+
     }
 
     /**

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

@@ -19,8 +19,8 @@ public class FindCommand extends Command {
 
     public static final String MESSAGE_USAGE = COMMAND_WORD + ": Finds all persons whose names contain any of "
             + "the specified keywords (case-insensitive) and displays them as a list with index numbers.\n"
-            + "Parameters: KEYWORD [MORE_KEYWORDS]...\n"
-            + "Example: " + COMMAND_WORD + " alice bob charlie";
+            + "Parameters: [n/nameKeyword] [r/roleKeyword] ...\n"
+            + "Example: " + COMMAND_WORD + " n/alice tan n/bob r/member n/charlie";
 
     private final NameContainsKeywordsPredicate namePredicate;
 

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

@@ -55,4 +55,7 @@ public static boolean areSomePrefixesPresent(ArgumentMultimap argumentMultimap,
         return Stream.of(prefixes).anyMatch(prefix -> argumentMultimap.getValue(prefix).isPresent());
     }
 
+
+
+
 }

src/test/java/seedu/address/logic/parser/FindCommandParserTest.java

@@ -21,6 +21,25 @@ public void parse_emptyArg_throwsParseException() {
         assertParseFailure(parser, "     ", String.format(MESSAGE_INVALID_COMMAND_FORMAT, FindCommand.MESSAGE_USAGE));
     }
 
+    @Test
+    public void parse_invalidPrefix_throwsParseException() {
+        assertParseFailure(parser, "t/chen", String.format(MESSAGE_INVALID_COMMAND_FORMAT, FindCommand.MESSAGE_USAGE));
+    }
+
+    @Test
+    public void parse_nonEmptyPreamble_throwsParseException() {
+        assertParseFailure(parser, " some random preamble",
+                String.format(MESSAGE_INVALID_COMMAND_FORMAT, FindCommand.MESSAGE_USAGE));
+    }
+
+    @Test
+    public void parse_emptyArgumentAfterPrefix_throwsParseException() {
+        assertParseFailure(parser, "n/ ",
+                String.format(MESSAGE_INVALID_COMMAND_FORMAT, FindCommand.MESSAGE_USAGE));
+        assertParseFailure(parser, "r/member    n/  ",
+                String.format(MESSAGE_INVALID_COMMAND_FORMAT, FindCommand.MESSAGE_USAGE));
+    }
+
     @Test
     public void parse_validArgs_returnsFindCommand() {
         // no leading and trailing whitespaces
@@ -30,7 +49,8 @@ public void parse_validArgs_returnsFindCommand() {
         assertParseSuccess(parser, " n/chen  n/albert  r/member r/exco ", expectedFindCommand);
 
         // multiple whitespaces between keywords
-        // assertParseSuccess(parser, " n/Alice ", expectedFindCommand);
+        assertParseSuccess(parser, " \n n/  chen  \n \t n/ albert \t r/ \t member r/ \n exco \t ",
+                expectedFindCommand);
     }
 
 }