Test examples
In this topic we show both the input source code, and the tests written by Diffblue Cover, for code of varied complexity, accompanied by a detailed narrative to help you further understand tests created by Diffblue Cover.
This is a simple example of Spring Service source code with a trivial getter. Cover can write a Spring Boot test for the getter in a service provider by inlining
Arrange, Act, and Assert.Source
import org.springframework.stereotype.Service;
@Service
public class SimpleService
{
public String getValue() {
return "a really simple service";
}
}
@SpringBootTest
@RunWith(org.springframework.test.context.junit4.SpringRunner.class)
public class SimpleServiceDiffblueTest {
@Autowired
private SimpleService simpleService;
@Test
public void diffbluetestGetValue() {
// Arrange, Act and Assert
assertEquals("a really simple service", this.simpleService.getValue());
}
}
This is a class that contains two methods to upload and download a file to/from an Amazon S3 bucket. As the Amazon S3 bucket is a cloud storage mechanism, the test for this class/methods requires dependency injection. Cover can mock these types of dependencies and tests
downloadFileFromBucket method by asserting the expected S3Object and the downloaded S3Object using the method.@Service
public class AmazonService {
@Autowired
private AmazonS3 s3client;
public PutObjectResult uploadFileToBucket(String bucketName, String key, File file) {
return s3client.putObject(bucketName, key, file);
}
public S3Object downloadFileFromBucket(String bucketName, String key) {
return s3client.getObject(bucketName, key);
}
}
@SpringBootTest
public class AmazonServiceDiffblueTest {
@MockBean
private AmazonS3Client amazonS3Client;
@Autowired
private AmazonService amazonService;
@Test
public void diffbluetestUploadFileToBucket() {
// Arrange
PutObjectResult putObjectResult = new PutObjectResult();
putObjectResult.setContentMd5("file-hash");
when(this.amazonS3Client.putObject(or(isA(String.class), isNull()), or(isA(String.class), isNull()),
or(isA(File.class), isNull()))).thenReturn(putObjectResult);
// Act and Assert
assertSame(putObjectResult, this.amazonService.uploadFileToBucket("foo", "foo",
Paths.get(System.getProperty("java.io.tmpdir"), "test.txt").toFile()));
}
@Test
public void diffbluetestDownloadFileFromBucket() throws UnsupportedEncodingException {
// Arrange
StringInputStream objectContent = new StringInputStream("file-name");
S3Object s3Object = new S3Object();
s3Object.setObjectContent(objectContent);
when(this.amazonS3Client.getObject(or(isA(String.class), isNull()), or(isA(String.class), isNull())))
.thenReturn(s3Object);
// Act and Assert
assertSame(s3Object, this.amazonService.downloadFileFromBucket("foo", "foo"));
}
}
This example returns time in a different format. Cover writes a test to assert date and time that is not dependent on operating system or local time zones.
public class TimeInAliceWonderland {
private static final String DODO_DATETIME_FORMAT = "ss:mm:HH dd-MMM-yyyy";
public static String reformatDodoDateTime(Date humanDate) {
Map<String, DateFormat> dateFormatMap = new HashMap<>();
dateFormatMap.put(DODO_DATETIME_FORMAT, new SimpleDateFormat(DODO_DATETIME_FORMAT));
return dateFormatMap.get(DODO_DATETIME_FORMAT).format(humanDate);
}
}
@Test
public void diffbluetestReformatDodoDateTime() {
LocalDateTime atStartOfDayResult = LocalDate.of(1970, 1, 1).atStartOfDay();
assertEquals("00:00:00 01-Jan-1970", TimeInAliceWonderland
.reformatDodoDateTime(
Date.from(atStartOfDayResult.atZone(ZoneId.systemDefault()).toInstant())));
}
In this example, Cover writes two tests to cover each pathway through the conditional - a test which adds 10 to the balance and asserts the new balance should be 20 and a second test where the account is closed.
public class Account {
private final long accountNumber;
private final Client client;
private long currentBalance;
private String accountName;
private AccountState accountState;
public Account(final long accountNumber, final Client client, final long amount) {
this.accountNumber = accountNumber;
this.client = client;
currentBalance = amount;
accountName = "Current";
accountState = AccountState.OPEN;
}
public long getCurrentBalance() {
return currentBalance;
}
public void addToBalance(final long amount) throws AccountException {
if (getAccountState() != AccountState.OPEN) {
throw new AccountException("Cannot add to balance, account is closed.");
}
currentBalance += amount;
}
@Test
public void diffbluetestAddToBalance() throws AccountException {
// Arrange
Account account = new Account(1234567890L, new Client("Carlos Welch"), 10L);
// Act
account.addToBalance(10L);
// Assert
assertEquals(20L, account.getCurrentBalance());
}
This example code has three branches - Cover covers 100% of branches and creates three tests for three cases using existing enum values.
public class VirtualSnackCupboard {
public static Snack whatCanISnackNow(int oClock) {
if (oClock == 10) {
return Snack.CHOCOLATE;
} else if (oClock == 15) {
return Snack.CAKES;
} else {
return Snack.VEGGIE;
}
}
enum Snack {VEGGIE, CHOCOLATE, CAKES}
}
public void diffbluetestPickSnack() {
assertEquals(VirtualSnackCupboard.Snack.CHOCOLATE, VirtualSnackCupboard.whatCanISnackNow(10));
assertEquals(VirtualSnackCupboard.Snack.CAKES, VirtualSnackCupboard.whatCanISnackNow(15));
assertEquals(VirtualSnackCupboard.Snack.VEGGIE, VirtualSnackCupboard.whatCanISnackNow(0));
}
Last modified 23d ago