The class MobileStorage is the implementation of a retro mobile phone's inbox. The inbox thereby is de ned to hold a prede ned maximum capacity of messages with up to 160 characters per message. The following operations are supported and need to be tested:
I need to do some Unit Testing on this code that i attached. Im not very familiar with TestNG and unit testing in general, can you help me with some examples of testing that i can do?
mobile_storage\src\main\java\MobileMessage.java - https://pastebin.com/RxNcgnSi
/**
* Represents a mobile text message.
*/
public class MobileMessage {
//stores the content of this messages
private final String text;
//in case of multi-part-messages, stores the preceding message
//is null in case of single message
private MobileMessage predecessor;
public MobileMessage(String text, MobileMessage predecessor) {
this.text = text;
this.predecessor = predecessor;
}
public String getText() {
return text;
}
public MobileMessage getPredecessor() {
return predecessor;
}
public void setPredecessor(MobileMessage predecessor) {
this.predecessor = predecessor;
}
}
mobile_storage\src\main\java\MobileStorage.java - https://pastebin.com/wuqKgvFD
import org.apache.commons.lang.StringUtils;
import java.util.Arrays;
import java.util.Objects;
import java.util.stream.IntStream;
/**
* Represents the message inbox of a mobile phone.
* Each storage position in the inbox can store a message with 160 characters at most.
* Messages are stored with increasing order (oldest first).
*/
public class MobileStorage {
final static int MAX_MESSAGE_LENGTH = 160;
private MobileMessage[] inbox;
private int occupied = 0;
/**
* Creates a message inbox that can store {@code storageSize} mobile messages.
* @throws IllegalArgumentException in case the passed {@code storageSize} is zero or less
*/
public MobileStorage(int storageSize) {
if(storageSize < 1) {
throw new IllegalArgumentException("Storage size must be greater than 0");
}
this.inbox = new MobileMessage[storageSize];
}
/**
* Stores a new text message to the inbox.
* In case the message text is longer than {@code MAX_MESSAGE_LENGTH}, the message is splitted and stored on multiple storage positions.
* @param message a non-empty message text
* @throws IllegalArgumentException in case the given message is empty
* @throws RuntimeException in case the available storage is too small for storing the complete message text
*/
public void saveMessage(String message) {
if(StringUtils.isBlank(message)) {
throw new IllegalArgumentException("Message cannot be null or empty");
}
int requiredStorage = (int) Math.ceil((double) message.length() / MAX_MESSAGE_LENGTH);
if(requiredStorage > inbox.length || (inbox.length - occupied) <= requiredStorage) {
throw new RuntimeException("Storage Overflow");
}
MobileMessage predecessor = null;
for(int i = 0; i < requiredStorage; i++) {
int from = i * MAX_MESSAGE_LENGTH;
int to = Math.min((i+1) * MAX_MESSAGE_LENGTH, message.length());
String messagePart = message.substring(from, to);
MobileMessage mobileMessage = new MobileMessage(messagePart, predecessor);
inbox[occupied] = mobileMessage;
occupied++;
predecessor = mobileMessage;
}
}
/**
* Returns the number of currently stored mobile messages.
*/
public int getOccupied() {
return occupied;
}
/**
* Removes the oldest (first) mobile message from the inbox.
*
* @return the deleted message
* @throws RuntimeException in case there are currently no messages stored
*/
public String deleteMessage() {
if(occupied == 0) {
throw new RuntimeException("There are no messages in the inbox");
}
MobileMessage first = inbox[0];
IntStream.range(1, occupied).forEach(index -> inbox[index-1] = inbox[index]);
inbox[occupied] = null;
inbox[0].setPredecessor(null);
occupied--;
return first.getText();
}
/**
* Returns a readable representation of all currently stored messages.
* Messages that were stored in multiple parts are joined together for representation.
* returns an empty String in case there are currently no messages stored
*/
public String listMessages() {
return Arrays.stream(inbox)
.filter(Objects::nonNull)
.collect(StringBuilder::new, MobileStorage::foldMessage, StringBuilder::append)
.toString();
}
private static void foldMessage(StringBuilder builder, MobileMessage message) {
if (message.getPredecessor() == null && builder.length() != 0) {
builder.append('\n');
}
builder.append(message.getText());
}
}
You will have to set up testNG . The way I test with testNG is with Eclipse and maven (dependency management). Once you have that , you can import classes in a test.java file in src folder under maven-Java project of eclipse.
You may need to adjust the code and import necessary classes for testNG. Here is the official documentation of testNG and here is the assert class.
I have tried to include some test cases. Hope this helps
Your test.java may look something like this
import yourPackage.MobileStorage;
import yourPackage. MobileMessage;
public class test{
@BeforeTest
public void prepareInstance(){
MobileStorage mobStg = new MobileStorage();
MobileMessage mobMsg = new MobileMessage();
}
//test simple msg
@Test
public void testSave(){
mobStg.saveMessage("hello")
assert.assertEquals("hello", mobMsg.getText())
}
//test msg with more chars
@Test
public void testMsgMoreChar(){
mobStg.saveMessage("messageWithMoreThan160Char")
//access messagepart here somehow, i am not sure of that
assert.assertEquals(mobMsg.getText(), mobStg.messagePart);
//access message here somehow. This will test listMessages() and concatenation of msgs
assert.assertEquals(mobStg.message, mobStg.listMessages())
}
//test deletion of msg
@Test
public void testDelete(){
mobStg.deleteMessage();
assert.assertEquals(null, mobMsg.getPredecessor())
}
}