[94] Fix compiler warnings (#117)

Author: damithc

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

@@ -2,7 +2,6 @@
 
 import java.util.Collection;
 import java.util.HashSet;
-import java.util.Objects;
 import java.util.Set;
 
 /**
@@ -22,29 +21,14 @@ public static boolean isAnyNull(Object... items) {
         return false;
     }
 
-    /**
-     * Throws an assertion error if any of the given arguments is null.
-     */
-    public static void assertNotNull(Object... items) {
-        int argIndex = 0;
-        for (Object item : items) {
-            if (Objects.isNull(item)) {
-                throw new AssertionError("Argument at index " + argIndex + " is null");
-            }
-            argIndex++;
-        }
-    }
+
 
     /**
      * Throws an assertion error if the collection or any item in it is null.
      */
     public static void assertNoNullElements(Collection<?> items) {
-        assertNotNull(items);
-        for (Object item : items) {
-            if (Objects.isNull(item)) {
-                throw new AssertionError("Collection has null element(s)");
-            }
-        }
+        assert items != null;
+        assert !isAnyNull(items);
     }
 
     /**

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

@@ -55,7 +55,7 @@ public ReadOnlyPerson getPerson() {
 
     @Override
     public CommandResult execute() {
-        CollectionUtil.assertNotNull(model);
+        assert model != null;
         try {
             model.addPerson(toAdd);
             return new CommandResult(String.format(MESSAGE_SUCCESS, toAdd));

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

@@ -19,7 +19,7 @@ public ClearCommand() {}
 
     @Override
     public CommandResult execute() {
-        CollectionUtil.assertNotNull(model);
+        assert model != null;
         model.resetData(AddressBook.getEmptyAddressBook());
         return new CommandResult(MESSAGE_SUCCESS);
     }

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

@@ -13,13 +13,14 @@ public class CommandResult {
     private final List<? extends ReadOnlyPerson> relevantPersons;
 
     public CommandResult(String feedbackToUser) {
-        CollectionUtil.assertNotNull(feedbackToUser);
+        assert feedbackToUser != null;
         this.feedbackToUser = feedbackToUser;
         relevantPersons = null;
     }
 
     public CommandResult(String feedbackToUser, List<? extends ReadOnlyPerson> relevantPersons) {
-        CollectionUtil.assertNotNull(feedbackToUser, relevantPersons);
+        assert feedbackToUser != null;
+        assert relevantPersons != null;
         this.feedbackToUser = feedbackToUser;
         this.relevantPersons = relevantPersons;
     }

src/main/java/seedu/address/model/person/Address.java

@@ -22,7 +22,7 @@ public class Address {
      * @throws IllegalValueException if given address string is invalid.
      */
     public Address(String address) throws IllegalValueException {
-        CollectionUtil.assertNotNull(address);
+        assert address != null;
         if (!isValidAddress(address)) {
             throw new IllegalValueException(MESSAGE_ADDRESS_CONSTRAINTS);
         }

src/main/java/seedu/address/model/person/Email.java

@@ -23,7 +23,7 @@ public class Email {
      * @throws IllegalValueException if given email address string is invalid.
      */
     public Email(String email) throws IllegalValueException {
-        CollectionUtil.assertNotNull(email);
+        assert email != null;
         email = email.trim();
         if (!isValidEmail(email)) {
             throw new IllegalValueException(MESSAGE_EMAIL_CONSTRAINTS);

src/main/java/seedu/address/model/person/Name.java

@@ -24,7 +24,7 @@ public class Name {
      * @throws IllegalValueException if given name string is invalid.
      */
     public Name(String name) throws IllegalValueException {
-        CollectionUtil.assertNotNull(name);
+        assert name != null;
         name = name.trim();
         if (!isValidName(name)) {
             throw new IllegalValueException(MESSAGE_NAME_CONSTRAINTS);

src/main/java/seedu/address/model/person/Person.java

@@ -22,7 +22,7 @@ public class Person implements ReadOnlyPerson {
      * Every field must be present and not null.
      */
     public Person(Name name, Phone phone, Email email, Address address, UniqueTagList tags) {
-        CollectionUtil.assertNotNull(name, phone, email, address, tags);
+        assert !CollectionUtil.isAnyNull(name, phone, email, address, tags);
         this.name = name;
         this.phone = phone;
         this.email = email;

src/main/java/seedu/address/model/person/Phone.java

@@ -21,7 +21,7 @@ public class Phone {
      * @throws IllegalValueException if given phone string is invalid.
      */
     public Phone(String phone) throws IllegalValueException {
-        CollectionUtil.assertNotNull(phone);
+        assert phone != null;
         phone = phone.trim();
         if (!isValidPhone(phone)) {
             throw new IllegalValueException(MESSAGE_PHONE_CONSTRAINTS);

src/main/java/seedu/address/model/person/UniquePersonList.java

@@ -43,7 +43,7 @@ public UniquePersonList() {}
      * Varargs/array constructor, enforces no nulls or duplicates.
      */
     public UniquePersonList(Person... persons) throws DuplicatePersonException {
-        CollectionUtil.assertNotNull(persons);
+        assert ! CollectionUtil.isAnyNull((Object[]) persons);
         final List<Person> initialPersons = Arrays.asList(persons);
         if (!CollectionUtil.elementsAreUnique(initialPersons)) {
             throw new DuplicatePersonException();
@@ -97,7 +97,7 @@ public Set<Person> toSet() {
      * Returns true if the list contains an equivalent person as the given argument.
      */
     public boolean contains(ReadOnlyPerson toCheck) {
-        CollectionUtil.assertNotNull(toCheck);
+        assert toCheck != null;
         return internalList.contains(toCheck);
     }
 
@@ -107,7 +107,7 @@ public boolean contains(ReadOnlyPerson toCheck) {
      * @throws DuplicatePersonException if the person to add is a duplicate of an existing person in the list.
      */
     public void add(Person toAdd) throws DuplicatePersonException {
-        CollectionUtil.assertNotNull(toAdd);
+        assert toAdd != null;
         if (contains(toAdd)) {
             throw new DuplicatePersonException();
         }
@@ -120,7 +120,7 @@ public void add(Person toAdd) throws DuplicatePersonException {
      * @throws PersonNotFoundException if no such person could be found in the list.
      */
     public boolean remove(ReadOnlyPerson toRemove) throws PersonNotFoundException {
-        CollectionUtil.assertNotNull(toRemove);
+        assert toRemove != null;
         final boolean personFoundAndDeleted = internalList.remove(toRemove);
         if (!personFoundAndDeleted) {
             throw new PersonNotFoundException();