When you run a JUnit 4 ParameterizedTest with the eclipse testrunner, the graphical representation is rather dumb: for each test you have a node called [0], [1], etc. Is it possible give the tests [0], [1] etc. explicit names? Implementing a toString method for the tests does not seem to help.
(This is a follow-up question to JUnit test with dynamic number of tests.)
I think there's nothing built in in jUnit 4 to do this.
I've implemented a solution. I've built my own Parameterized class based on the existing one:
public class MyParameterized extends TestClassRunner {
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public static @interface Parameters {
}
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public static @interface Name {
}
public static Collection<Object[]> eachOne(Object... params) {
List<Object[]> results = new ArrayList<Object[]>();
for (Object param : params)
results.add(new Object[] { param });
return results;
}
// TODO: single-class this extension
private static class TestClassRunnerForParameters extends TestClassMethodsRunner {
private final Object[] fParameters;
private final Class<?> fTestClass;
private Object instance;
private final int fParameterSetNumber;
private final Constructor<?> fConstructor;
private TestClassRunnerForParameters(Class<?> klass, Object[] parameters, int i) throws Exception {
super(klass);
fTestClass = klass;
fParameters = parameters;
fParameterSetNumber = i;
fConstructor = getOnlyConstructor();
instance = fConstructor.newInstance(fParameters);
}
@Override
protected Object createTest() throws Exception {
return instance;
}
@Override
protected String getName() {
String name = null;
try {
Method m = getNameMethod();
if (m != null)
name = (String) m.invoke(instance);
} catch (Exception e) {
}
return String.format("[%s]", (name == null ? fParameterSetNumber : name));
}
@Override
protected String testName(final Method method) {
String name = null;
try {
Method m = getNameMethod();
if (m != null)
name = (String) m.invoke(instance);
} catch (Exception e) {
}
return String.format("%s[%s]", method.getName(), (name == null ? fParameterSetNumber : name));
}
private Constructor<?> getOnlyConstructor() {
Constructor<?>[] constructors = getTestClass().getConstructors();
assertEquals(1, constructors.length);
return constructors[0];
}
private Method getNameMethod() throws Exception {
for (Method each : fTestClass.getMethods()) {
if (Modifier.isPublic((each.getModifiers()))) {
Annotation[] annotations = each.getAnnotations();
for (Annotation annotation : annotations) {
if (annotation.annotationType() == Name.class) {
if (each.getReturnType().equals(String.class))
return each;
else
throw new Exception("Name annotated method doesn't return an object of type String.");
}
}
}
}
return null;
}
}
// TODO: I think this now eagerly reads parameters, which was never the
// point.
public static class RunAllParameterMethods extends CompositeRunner {
private final Class<?> fKlass;
public RunAllParameterMethods(Class<?> klass) throws Exception {
super(klass.getName());
fKlass = klass;
int i = 0;
for (final Object each : getParametersList()) {
if (each instanceof Object[])
super.add(new TestClassRunnerForParameters(klass, (Object[]) each, i++));
else
throw new Exception(String.format("%s.%s() must return a Collection of arrays.", fKlass.getName(), getParametersMethod().getName()));
}
}
private Collection<?> getParametersList() throws IllegalAccessException, InvocationTargetException, Exception {
return (Collection<?>) getParametersMethod().invoke(null);
}
private Method getParametersMethod() throws Exception {
for (Method each : fKlass.getMethods()) {
if (Modifier.isStatic(each.getModifiers())) {
Annotation[] annotations = each.getAnnotations();
for (Annotation annotation : annotations) {
if (annotation.annotationType() == Parameters.class)
return each;
}
}
}
throw new Exception("No public static parameters method on class " + getName());
}
}
public MyParameterized(final Class<?> klass) throws Exception {
super(klass, new RunAllParameterMethods(klass));
}
@Override
protected void validate(MethodValidator methodValidator) {
methodValidator.validateStaticMethods();
methodValidator.validateInstanceMethods();
}
}
To be used like:
@RunWith(MyParameterized.class)
public class ParameterizedTest {
private File file;
public ParameterizedTest(File file) {
this.file = file;
}
@Test
public void test1() throws Exception {}
@Test
public void test2() throws Exception {}
@Name
public String getName() {
return "coolFile:" + file.getName();
}
@Parameters
public static Collection<Object[]> data() {
// load the files as you want
Object[] fileArg1 = new Object[] { new File("path1") };
Object[] fileArg2 = new Object[] { new File("path2") };
Collection<Object[]> data = new ArrayList<Object[]>();
data.add(fileArg1);
data.add(fileArg2);
return data;
}
}
This implies that I instantiate the test class earlier. I hope this won't cause any errors ... I guess I should test the tests :)
There's no hint that this feature is or will be implemented. I would request this feature because it's nice to have.
A code-less though not that comfortable solution is to pass enough context information to identify the test in assert messages. You will still see just testXY[0] failed but the detailed message tells you which one was that.
assertEquals("Not the expected decission for the senator " + this.currentSenatorName + " and the law " + this.votedLaw,
expectedVote, actualVote);