142 lines
3.2 KiB
Java
142 lines
3.2 KiB
Java
package org.gcube.data.streams.test;
|
|
|
|
|
|
import java.util.ArrayList;
|
|
import java.util.List;
|
|
import java.util.NoSuchElementException;
|
|
|
|
import org.gcube.data.streams.Stream;
|
|
import org.gcube.data.streams.exceptions.StreamSkipSignal;
|
|
|
|
/**
|
|
* Collection of test facilities to validate {@link Stream} implementation and their usage.
|
|
*
|
|
* @author Fabio Simeoni
|
|
*
|
|
*/
|
|
public class Utils {
|
|
|
|
|
|
/**
|
|
* Returns the elements of a {@link Stream} as a {@link List}, including failures.
|
|
* @param stream the stream
|
|
* @return the elements
|
|
*/
|
|
public static List<Object> elementsOf(Stream<?> stream) {
|
|
|
|
List<Object> outcomes = new ArrayList<Object>();
|
|
|
|
//consume
|
|
while (stream.hasNext())
|
|
try {
|
|
Object e = stream.next();
|
|
outcomes.add(e);
|
|
}
|
|
catch(StreamSkipSignal skip) {
|
|
continue;
|
|
}
|
|
catch(RuntimeException ex) {
|
|
outcomes.add(ex);
|
|
}
|
|
|
|
stream.close();
|
|
|
|
return outcomes;
|
|
}
|
|
|
|
/**
|
|
* Applies a set of sets to test a stream respects the constraints defined by the interface.
|
|
* @param provider a {@link StreamProvider} that repeatedly provides the stream to test
|
|
*/
|
|
public static void validateWith(StreamProvider provider) {
|
|
|
|
isAddressableAndClosable(provider.get());
|
|
canBeIteratedOver(provider.get());
|
|
respectsCloseSemantics(provider.get());
|
|
|
|
}
|
|
|
|
//a validation test
|
|
private static void isAddressableAndClosable(Stream<?> stream) {
|
|
|
|
if (stream.locator()==null)
|
|
throw new AssertionError("locator is null");
|
|
|
|
if (stream.isClosed())
|
|
throw new AssertionError("stream is already closed");
|
|
|
|
|
|
stream.close();
|
|
|
|
if (!stream.isClosed())
|
|
throw new AssertionError("stream has not been closed");
|
|
}
|
|
|
|
//a validation test
|
|
private static void respectsCloseSemantics(Stream<?> stream) {
|
|
|
|
if (stream.isClosed())
|
|
throw new AssertionError("stream is already closed");
|
|
|
|
stream.close();
|
|
|
|
if (!stream.isClosed())
|
|
throw new AssertionError("stream has been closed but does not reveal it");
|
|
|
|
if (stream.hasNext())
|
|
throw new AssertionError("stream indicates that it has elements after being closed");
|
|
|
|
|
|
try {
|
|
stream.next();
|
|
throw new AssertionError("stream returns elements after being closed");
|
|
}
|
|
catch(NoSuchElementException ex) {
|
|
//expected
|
|
}
|
|
|
|
}
|
|
|
|
//a validation test
|
|
private static void canBeIteratedOver(Stream<?> stream) {
|
|
|
|
//can be iterated without hasNext();
|
|
try {
|
|
if (stream.next()==null)
|
|
throw new AssertionError("next() returns null");
|
|
}
|
|
catch(NoSuchElementException e) {
|
|
if (stream.hasNext())
|
|
throw new AssertionError("stream has no elements but hasNext() returns true");
|
|
}
|
|
catch (RuntimeException e) {
|
|
//ignore exception for this test
|
|
}
|
|
|
|
//consume
|
|
while (stream.hasNext())
|
|
try {
|
|
if (stream.next()==null)
|
|
throw new AssertionError("hasNext() returns true but next() returns null");
|
|
}
|
|
catch(RuntimeException e) {
|
|
//ignore exceptions for this test
|
|
}
|
|
|
|
//hasNext() is idempotent
|
|
if (stream.hasNext())
|
|
throw new AssertionError("hasNext() is not idempotent");
|
|
|
|
//verify reading past end
|
|
try {
|
|
stream.next();
|
|
throw new AssertionError("stream can be read past its end");
|
|
}
|
|
catch(NoSuchElementException e) {
|
|
//expected
|
|
}
|
|
|
|
stream.close();
|
|
}
|
|
}
|