Add sample assignment data if file not found

src/main/java/seedu/address/MainApp.java

@@ -23,6 +23,7 @@
 import seedu.address.model.UserPrefs;
 import seedu.address.model.assignment.PredefinedAssignmentsData;
 import seedu.address.model.assignment.ReadOnlyPredefinedAssignmentsData;
+import seedu.address.model.util.SampleAssignmentsUtil;
 import seedu.address.model.util.SampleDataUtil;
 import seedu.address.storage.AddressBookStorage;
 import seedu.address.storage.JsonAddressBookStorage;
@@ -92,8 +93,13 @@ private Model initModelManager(Storage storage, ReadOnlyUserPrefs userPrefs) {
                 logger.info("Creating a new data file " + storage.getAddressBookFilePath()
                         + " populated with a sample AddressBook.");
             }
+            if (!readAssignmentOptional.isPresent()) {
+                logger.info("Creating a new data file " + storage.getAssignmentFilePath()
+                        + " populated with a sample assignment file.");
+            }
             initialData = addressBookOptional.orElseGet(SampleDataUtil::getSampleAddressBook);
-            predefinedAssignments = readAssignmentOptional.orElseGet(PredefinedAssignmentsData::new);
+            predefinedAssignments = readAssignmentOptional
+                    .orElseGet(SampleAssignmentsUtil::getSamplePredefinedAssignments);
         } catch (DataLoadingException e) {
             logger.warning("Data file at " + storage.getAddressBookFilePath() + " could not be loaded."
                     + " Will be starting with an empty AddressBook.");

src/main/java/seedu/address/model/assignment/PredefinedAssignmentsData.java

@@ -74,4 +74,14 @@ public String getAssignmentName(String name) {
         }
         return null;
     }
+
+    /**
+     * Adds a predefined assignment to predefinedAssignmentArrayList.
+     * @param p The predefined assignment to add.
+     * @return The predefinedAssignmentArrayList.
+     */
+    public ArrayList<PredefinedAssignment> add(PredefinedAssignment p) {
+        predefinedAssignmentArrayList.add(p);
+        return predefinedAssignmentArrayList;
+    }
 }

src/main/java/seedu/address/model/util/SampleAssignmentsUtil.java

@@ -0,0 +1,33 @@
+package seedu.address.model.util;
+
+import seedu.address.model.assignment.PredefinedAssignment;
+import seedu.address.model.assignment.PredefinedAssignmentsData;
+import seedu.address.model.assignment.ReadOnlyPredefinedAssignmentsData;
+
+/**
+ * Contains utility methods for populating
+ * {@code PredefinedAssignmentsData} with sample data.
+ */
+public class SampleAssignmentsUtil {
+    public static PredefinedAssignment[] getSampleAssignments() {
+        return new PredefinedAssignment[]{
+            new PredefinedAssignment("Ex01", 10f),
+            new PredefinedAssignment("Ex02", 10f),
+            new PredefinedAssignment("Ex03", 25f)
+        };
+    }
+
+    /**
+     * Returns predefined assignments database populated with the sample assignments.
+     *
+     * @return The sample predefined assignment database.
+     */
+    public static ReadOnlyPredefinedAssignmentsData getSamplePredefinedAssignments() {
+        PredefinedAssignmentsData samplePredefinedAssignment =
+                new PredefinedAssignmentsData();
+        for (PredefinedAssignment sample : getSampleAssignments()) {
+            samplePredefinedAssignment.add(sample);
+        }
+        return samplePredefinedAssignment;
+    }
+}

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

@@ -11,38 +11,29 @@
 import seedu.address.model.Model;
 import seedu.address.model.ModelManager;
 import seedu.address.model.UserPrefs;
-import seedu.address.model.assignment.PredefinedAssignment;
-import seedu.address.model.assignment.PredefinedAssignmentsData;
 import seedu.address.model.person.Person;
+import seedu.address.model.util.SampleAssignmentsUtil;
 import seedu.address.testutil.TypicalPersons;
 
 public class AddGradeCommandTest {
     private final Model model = new ModelManager(
-        getTypicalAddressBook(),
-        new UserPrefs(),
-        AddGradeCommandTest.getPredefinedAssignmentsData());
-
-
-    public static PredefinedAssignmentsData getPredefinedAssignmentsData() {
-        PredefinedAssignmentsData predefinedAssignmentsData = new PredefinedAssignmentsData();
-        predefinedAssignmentsData.addPredefinedAssignment(new PredefinedAssignment("Ex01", 10.0f));
-        predefinedAssignmentsData.addPredefinedAssignment(new PredefinedAssignment("Ex02", 10.0f));
-        predefinedAssignmentsData.addPredefinedAssignment(new PredefinedAssignment("Ex09", 10.0f));
-        return predefinedAssignmentsData;
-    }
-
+            getTypicalAddressBook(),
+            new UserPrefs(),
+            SampleAssignmentsUtil.getSamplePredefinedAssignments());
 
 
     @Test
     public void constructor_nullAssignmentFormat_throwsNullPointerException() {
 
         assertThrows(NullPointerException.class, () -> new AddGradeCommand(null, 0f, null));
     }
+
     @Test
     public void assignment_invalidName() {
         AddGradeCommand command = new AddGradeCommand("John Doe", 0f, "ex10");
         assertThrows(CommandException.class, () -> command.execute(model));
     }
+
     @Test
     public void person_invalidName() {
         AddGradeCommand command = new AddGradeCommand("John DoeDoedoe", 0f, "ex01");
@@ -52,14 +43,14 @@ public void person_invalidName() {
     @Test
     public void assignment_invalidHighScore() {
         AddGradeCommand command = new AddGradeCommand("John Doe",
-            100f, "ex01");
+                100f, "ex01");
         assertThrows(CommandException.class, () -> command.execute(model));
     }
 
     @Test
     public void assignment_invalidLowScore() {
         AddGradeCommand command = new AddGradeCommand("John Doe",
-            -1f, "ex01");
+                -1f, "ex01");
         assertThrows(CommandException.class, () -> command.execute(model));
     }
 

src/test/java/seedu/address/model/assignment/PredefinedAssignmentsDataTest.java

@@ -0,0 +1,20 @@
+package seedu.address.model.assignment;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+
+class PredefinedAssignmentsDataTest {
+
+    @Test
+    public void addTest() {
+        PredefinedAssignment sample = new PredefinedAssignment("Ex01", 0f);
+        PredefinedAssignmentsData data = new PredefinedAssignmentsData();
+        ArrayList<PredefinedAssignment> expected = new ArrayList<>(List.of(sample));
+        assertEquals(data.add(sample), expected);
+    }
+}