// License: GPL. For details, see LICENSE file.
package org.openstreetmap.josm.gui;
import static org.junit.Assert.assertNotNull;
import java.lang.reflect.Constructor;
import java.lang.reflect.Modifier;
import java.util.Arrays;
import java.util.Collection;
import java.util.Set;
import javax.swing.JTable;
import javax.swing.table.TableCellRenderer;
import org.junit.Assert;
import org.junit.BeforeClass;
import org.junit.Test;
import org.openstreetmap.josm.JOSMFixture;
import org.openstreetmap.josm.tools.Utils;
import org.reflections.Reflections;
/**
* Checks if all classes implementing the {@link TableCellRenderer} interface do
* accept a null value as second parameter for
* {@link TableCellRenderer#getTableCellRendererComponent(javax.swing.JTable,
* java.lang.Object, boolean, boolean, int, int)}.
*
* For unknown reason java sometimes call getTableCellRendererComponent method
* with value = null. Every implementation of {@code getTableCellRendererComponent}
* must fail gracefully when null is passed as value parameter.
*
* This test scans the classpath for classes implementing {@code TableCellRenderer},
* creates an instance and calls {@code getTableCellRendererComponent} with null
* value to check if a NPE is thrown.
*
* @see <a href="https://josm.openstreetmap.de/ticket/6301">#6301</a>
*/
public class TableCellRendererTest {
// list of classes that cannot be easily tested and are verified either manually or another unit tests
private static final Collection<String> SKIP_TEST = Arrays.asList(
"org.openstreetmap.josm.gui.dialogs.FilterDialog$BooleanRenderer",
"org.openstreetmap.josm.gui.dialogs.relation.SelectionTableCellRenderer"
);
/**
* Setup test.
*/
@BeforeClass
public static void setUp() {
JOSMFixture.createFunctionalTestFixture().init(true);
}
/**
* Unit test of all table cell renderers against null values.
* @throws NoSuchMethodException no default constructor - to fix this, add a default constructor to the class
* or add the class to the SKIP_TEST list above
* @throws ReflectiveOperationException if an error occurs
*/
@Test
public void testTableCellRenderer() throws ReflectiveOperationException {
Reflections reflections = new Reflections("org.openstreetmap.josm");
Set<Class<? extends TableCellRenderer>> renderers = reflections.getSubTypesOf(TableCellRenderer.class);
Assert.assertTrue(renderers.size() >= 10); // if it finds less than 10 classes, something is broken
JTable tbl = new JTable(2, 2);
for (Class<? extends TableCellRenderer> klass : renderers) {
if (Modifier.isAbstract(klass.getModifiers()) || SKIP_TEST.contains(klass.getName())) {
continue;
}
if (klass.isAnonymousClass()) {
continue;
}
assertNotNull(createInstance(klass).getTableCellRendererComponent(tbl, null, false, false, 0, 0));
}
}
/**
* Create an instance of a class assuming it has a no-args constructor.
* @param <T> the class or a super-type of the class
* @param klass the class
* @return an instance of the class
* @throws NoSuchMethodException no default constructor - to fix this, add a default constructor to the class
* or add the class to the SKIP_TEST list above
* @throws ReflectiveOperationException if an error occurs
*/
private static <T> T createInstance(Class<? extends T> klass) throws ReflectiveOperationException {
boolean needOuterClass = klass.isMemberClass() && !Modifier.isStatic(klass.getModifiers());
Constructor<? extends T> c;
if (needOuterClass) {
c = klass.getDeclaredConstructor(klass.getDeclaringClass());
} else {
c = klass.getDeclaredConstructor();
}
Utils.setObjectsAccessible(c);
if (needOuterClass) {
return c.newInstance(createInstance(klass.getDeclaringClass()));
} else {
return c.newInstance();
}
}
}