package seedu.tasklist.commons.util;

import static org.junit.Assert.assertNotNull;

import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ExpectedException;

public class AppUtilTest {

    @Rule
    public ExpectedException thrown = ExpectedException.none();



    @Test
    public void getImage_exitingImage() {
        assertNotNull(AppUtil.getImage("/images/address_book_32.png"));
    }


    @Test
    public void getImage_nullGiven_assertionError() {
        thrown.expect(AssertionError.class);
        AppUtil.getImage(null);
    }


}

@@ -76,16 +76,59 @@
 NotNull;
+%0Aimport static org.junit.Assert.assertNull;
 %0A%0Aimport
@@ -314,16 +314,38 @@
 ne();%0A%0A%0A
+    //author A0141993X
 %0A    @Te
@@ -375,16 +375,17 @@
 mage_exi
+s
 tingImag
@@ -442,30 +442,208 @@
 ges/
-address_book_3
+flexiTaskAppIcon.png%22));%0A    %7D%0A    %0A    @Test%0A    public void getImage_nonExistingImage() %7B%0A        thrown.expect(NullPointerException.class);%0A        AppUtil.getImage(%22/images/flexiTaskAppIcon
 2.png%22)
-)
 ;%0A  
@@ -647,16 +647,26 @@
 %0A    %7D%0A%0A
+//@@author
 %0A    @Te

Add test case in AppUtilTest.java