Add test for payment command

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

@@ -59,7 +59,7 @@ public boolean equals(Object other) {
     @Override
     public String toString() {
         return new ToStringBuilder(this.getClass().getSimpleName())
-                .add("payment", filteredPayment)
+                .add("Payment", filteredPayment)
                 .toString();
     }
 }

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

@@ -0,0 +1,97 @@
+package seedu.address.logic.commands;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static seedu.address.logic.commands.CommandTestUtil.assertCommandSuccess;
+import static seedu.address.logic.commands.FilterCommand.MESSAGE_FILTER_ADDRESS_BOOK_SUCCESS;
+import static seedu.address.testutil.TypicalPersons.ALICE;
+import static seedu.address.testutil.TypicalPersons.BENSON;
+import static seedu.address.testutil.TypicalPersons.CARL;
+import static seedu.address.testutil.TypicalPersons.DANIEL;
+import static seedu.address.testutil.TypicalPersons.ELLE;
+import static seedu.address.testutil.TypicalPersons.FIONA;
+import static seedu.address.testutil.TypicalPersons.GEORGE;
+import static seedu.address.testutil.TypicalPersons.getTypicalAddressBook;
+
+import java.util.Arrays;
+import java.util.Collections;
+
+import org.junit.jupiter.api.Test;
+
+import seedu.address.logic.Messages;
+import seedu.address.model.CommandHistory;
+import seedu.address.model.Model;
+import seedu.address.model.ModelManager;
+import seedu.address.model.UserPrefs;
+import seedu.address.model.person.*;
+
+
+/**
+ * Contains integration tests (interaction with the Model) for {@code PaymentCommand}.
+ */
+public class PaymentCommandTest {
+    private Model model = new ModelManager(getTypicalAddressBook(), new UserPrefs(), new CommandHistory());
+    private Model expectedModel = new ModelManager(getTypicalAddressBook(), new UserPrefs(), new CommandHistory());
+
+    @Test
+    public void equals() {
+        PaymentFilterPredicate firstPredicate =
+                new PaymentFilterPredicate(new Payment());
+        PaymentFilterPredicate secondPredicate =
+                new PaymentFilterPredicate(new Payment("Paid"));
+
+        PaymentCommand PaymentFirstCommand = new PaymentCommand(firstPredicate);
+        PaymentCommand PaymentSecondCommand = new PaymentCommand(secondPredicate);
+
+        // same object -> returns true
+        assertTrue(PaymentFirstCommand.equals(PaymentFirstCommand));
+
+        // same values -> returns true
+        PaymentCommand findFirstCommandCopy = new PaymentCommand(firstPredicate);
+        assertTrue(PaymentFirstCommand.equals(findFirstCommandCopy));
+
+        // different types -> returns false
+        assertFalse(PaymentFirstCommand.equals(1));
+
+        // null -> returns false
+        assertFalse(PaymentFirstCommand.equals(null));
+
+        // different person -> returns false
+        assertFalse(PaymentFirstCommand.equals(PaymentSecondCommand));
+    }
+
+    @Test
+    public void execute_filterPayment_noStudentFound() {
+        PaymentFilterPredicate predicate =
+                new PaymentFilterPredicate(new Payment("Not Paid"));
+        String expectedMessage =
+                String.format(MESSAGE_FILTER_ADDRESS_BOOK_SUCCESS + Messages.MESSAGE_PERSONS_LISTED_OVERVIEW,
+                        0, predicate.filterResult());
+        PaymentCommand command = new PaymentCommand(predicate);
+        expectedModel.updateFilteredPersonList(predicate);
+        assertCommandSuccess(command, model, expectedMessage, expectedModel);
+        assertEquals(Collections.emptyList(), model.getFilteredPersonList());
+    }
+
+    @Test
+    public void execute_filterPayment_multipleStudentsFound() {
+        PaymentFilterPredicate predicate =
+                new PaymentFilterPredicate(new Payment("Paid"));
+        String expectedMessage =
+                String.format(MESSAGE_FILTER_ADDRESS_BOOK_SUCCESS + Messages.MESSAGE_PERSONS_LISTED_OVERVIEW,
+                        7, predicate.filterResult());
+        PaymentCommand command = new PaymentCommand(predicate);
+        expectedModel.updateFilteredPersonList(predicate);
+        assertCommandSuccess(command, model, expectedMessage, expectedModel);
+        assertEquals(Arrays.asList(ALICE, BENSON, CARL, DANIEL, ELLE, FIONA, GEORGE), model.getFilteredPersonList());
+    }
+
+    @Test
+    public void toStringMethod() {
+        PaymentFilterPredicate predicate = new PaymentFilterPredicate(new Payment());
+        PaymentCommand filterCommand = new PaymentCommand(predicate);
+        String expected = PaymentCommand.class.getSimpleName() + "{predicate=" + predicate + "}";
+        assertEquals(expected, filterCommand.toString());
+    }
+}

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

@@ -0,0 +1,35 @@
+package seedu.address.logic.parser;
+
+import static seedu.address.logic.Messages.MESSAGE_INVALID_COMMAND_FORMAT;
+import static seedu.address.logic.parser.CommandParserTestUtil.assertParseFailure;
+import static seedu.address.logic.parser.CommandParserTestUtil.assertParseSuccess;
+
+import org.junit.jupiter.api.Test;
+
+import seedu.address.logic.commands.PaymentCommand;
+import seedu.address.model.person.Payment;
+import seedu.address.model.person.PaymentFilterPredicate;
+
+
+public class PaymentCommandParserTest {
+
+    private PaymentCommandParser parser = new PaymentCommandParser();
+
+    @Test
+    public void parse_emptyArg_throwsParseException() {
+        assertParseFailure(parser, "     ",
+                String.format(MESSAGE_INVALID_COMMAND_FORMAT, PaymentCommand.MESSAGE_USAGE));
+    }
+
+    @Test
+    public void parse_validArgs_returnsFilterCommand() {
+        // no trailing whitespaces
+        PaymentCommand expectedPaymentCommand =
+                new PaymentCommand(new PaymentFilterPredicate(new Payment("Paid")));
+        assertParseSuccess(parser, " pa/paid", expectedPaymentCommand);
+
+        // multiple whitespaces between keywords
+        assertParseSuccess(parser, " \n pa/ \n \t paid  \t", expectedPaymentCommand);
+    }
+
+}

src/test/java/seedu/address/model/person/PaymentPredicateTest.java

@@ -0,0 +1,58 @@
+package seedu.address.model.person;
+
+import org.junit.jupiter.api.Test;
+import seedu.address.testutil.PersonBuilder;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class PaymentPredicateTest {
+
+    @Test
+    public void equals() {
+        PaymentFilterPredicate firstPredicate = new PaymentFilterPredicate(
+                new Payment());
+
+        PaymentFilterPredicate secondPredicate = new PaymentFilterPredicate(
+                new Payment("Paid"));
+
+        // same object -> returns true
+        assertTrue(firstPredicate.equals(firstPredicate));
+
+        // same values -> returns true
+        PaymentFilterPredicate firstPredicateCopy = new PaymentFilterPredicate(
+                new Payment());
+        assertTrue(firstPredicate.equals(firstPredicateCopy));
+
+        // different types -> returns false
+        assertFalse(firstPredicate.equals(1));
+
+        // null -> returns false
+        assertFalse(firstPredicate.equals(null));
+
+        // different filter -> returns false
+        assertFalse(firstPredicate.equals(secondPredicate));
+    }
+
+    @Test
+    public void test_filterContainsPayment_returnsTrue() {
+        PaymentFilterPredicate predicate = new PaymentFilterPredicate(new Payment("Paid"));
+        assertTrue(predicate.test(new PersonBuilder().withName("Alice Bob").build()));
+    }
+
+    @Test
+    public void test_filterContainsGradeSubject_returnsFalse() {
+        PaymentFilterPredicate predicate = new PaymentFilterPredicate(
+                new Payment("Not Paid"));
+        assertFalse(predicate.test(new PersonBuilder().withName("Alice").build()));
+    }
+
+    @Test
+    public void toStringMethod() {
+        String payment = "Paid";
+        PaymentFilterPredicate predicate = new PaymentFilterPredicate(
+                new Payment(payment));
+
+        String expected = PaymentFilterPredicate.class.getSimpleName() + "{Payment=" + payment + "}";
+        assertEquals(expected, predicate.toString());
+    }
+}