Add all required tests

src/test/java/seedu/todo/logic/commands/ViewCommandTest.java

@@ -0,0 +1,152 @@
+package seedu.todo.logic.commands;
+
+import static org.hamcrest.Matchers.*;
+import static org.junit.Assert.*;
+
+import java.time.LocalDateTime;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import seedu.todo.commons.enumerations.TaskViewFilter;
+import seedu.todo.commons.events.ui.ChangeViewRequestEvent;
+import seedu.todo.commons.exceptions.ValidationException;
+import seedu.todo.logic.commands.ViewCommand;
+import seedu.todo.model.task.ImmutableTask;
+import seedu.todo.testutil.EventsCollector;
+
+//@@ author A0092382A
+public class ViewCommandTest extends CommandTest {
+
+    EventsCollector eventsCollector = new EventsCollector();
+    ChangeViewRequestEvent event;
+    ImmutableTask task1, task2, task3;
+    @Override
+    protected BaseCommand commandUnderTest() {
+        return new ViewCommand();
+    }
+
+    @Before
+    public void setUp() throws Exception {
+        model.add("Task 3", task -> { task.setCompleted(true); task.setEndTime(LocalDateTime.now().plusDays(1)); });
+        model.add("Task 2", task -> { task.setCompleted(false); task.setEndTime(LocalDateTime.now().plusDays(4));});
+        model.add("Task 1", task -> { task.setCompleted(false); task.setEndTime(LocalDateTime.now());});
+        task1 = getTaskAt(1);
+        task2 = getTaskAt(2);
+        task3 = getTaskAt(3);
+
+    }
+
+    @Test
+    public void testViewDefault() throws ValidationException {
+        assertVisibleTaskCount(3);
+        setParameter("show all");
+        execute(true);
+        assertVisibleTaskCount(3);
+        assertThat(eventsCollector.get(0), instanceOf(ChangeViewRequestEvent.class));
+        event = (ChangeViewRequestEvent) eventsCollector.get(0);
+        assertEquals(event.getNewView(), TaskViewFilter.DEFAULT);
+        assertTaskVisible(task1);
+        assertTaskVisible(task2);
+        assertTaskVisible(task3);
+    }
+
+    @Test (expected = ValidationException.class)
+    public void testInvalidView() throws ValidationException {
+        assertEquals( model.getObserveableList().size(), 3);
+        setParameter("de fault");
+        execute(false);
+        //checkFeedback received
+    }
+
+    @Test
+    public void testViewCompleted() throws ValidationException {
+        assertVisibleTaskCount(3);
+        setParameter("completed");
+        execute(true);
+        assertVisibleTaskCount(1);
+        assertThat(eventsCollector.get(0), instanceOf(ChangeViewRequestEvent.class));
+        event = (ChangeViewRequestEvent) eventsCollector.get(0);
+        assertEquals(event.getNewView(), TaskViewFilter.COMPLETED);
+        assertTaskNotVisible(task1);
+        assertTaskNotVisible(task2);
+        assertTaskVisible(task3);
+    }
+
+    @Test
+    public void testViewIncomplete() throws ValidationException {
+        assertVisibleTaskCount(3);
+        setParameter("incomplete");
+        execute(true);
+        assertVisibleTaskCount(2);
+        assertThat(eventsCollector.get(0), instanceOf(ChangeViewRequestEvent.class));
+        event = (ChangeViewRequestEvent) eventsCollector.get(0);
+        assertEquals(event.getNewView(), TaskViewFilter.INCOMPLETE);
+        assertTaskVisible(task1);
+        assertTaskVisible(task2);
+        assertTaskNotVisible(task3);
+        }
+
+
+    @Test
+    public void testCaseInsensitive() throws ValidationException {
+        assertEquals( model.getObserveableList().size(), 3);
+        setParameter("Incomplete");
+        execute(true);
+        assertEquals( model.getObserveableList().size(), 2);
+        assertThat(eventsCollector.get(0), instanceOf(ChangeViewRequestEvent.class));
+        event = (ChangeViewRequestEvent) eventsCollector.get(0);
+        assertEquals(event.getNewView(), TaskViewFilter.INCOMPLETE);
+        assertTaskVisible(task1);
+        assertTaskVisible(task2);
+        assertTaskNotVisible(task3);
+    }
+
+    @Test
+    public void testViewDueToday() throws ValidationException {
+        assertEquals( model.getObserveableList().size(), 3);
+        setParameter("due today");
+        execute(true);
+        assertVisibleTaskCount(1);
+        assertThat(eventsCollector.get(0), instanceOf(ChangeViewRequestEvent.class));
+        event = (ChangeViewRequestEvent) eventsCollector.get(0);
+        assertEquals(event.getNewView(), TaskViewFilter.DUE_TODAY);
+        assertTaskVisible(task1);
+        assertTaskNotVisible(task2);
+        assertTaskNotVisible(task3);
+
+    }
+
+    @Test
+    public void testSuccessiveCommands() throws ValidationException {
+        assertEquals( model.getObserveableList().size(), 3);
+        setParameter("due today");
+        execute(true);
+        assertTaskVisible(task1);
+        assertTaskNotVisible(task2);
+        assertTaskNotVisible(task3);
+        assertVisibleTaskCount(1);
+
+
+        setParameter("incomplete");
+        execute(true);
+        assertTaskVisible(task1);
+        assertTaskVisible(task2);
+        assertTaskNotVisible(task3);
+        assertVisibleTaskCount(2);
+
+        setParameter("show all");
+        execute(true);
+        assertTaskVisible(task1);
+        assertTaskVisible(task2);
+        assertTaskVisible(task3);
+        assertVisibleTaskCount(3);
+        assertEquals(eventsCollector.size(), 3);
+
+    }
+
+
+
+
+
+}