package org.junit.runner;
import java.util.Comparator;
import org.junit.internal.builders.AllDefaultPossibilitiesBuilder;
import org.junit.internal.requests.ClassRequest;
import org.junit.internal.requests.FilterRequest;
import org.junit.internal.requests.OrderingRequest;
import org.junit.internal.requests.SortingRequest;
import org.junit.internal.runners.ErrorReportingRunner;
import org.junit.runner.manipulation.Filter;
import org.junit.runner.manipulation.Ordering;
import org.junit.runners.model.InitializationError;
/**
* A <code>Request</code> is an abstract description of tests to be run. Older versions of
* JUnit did not need such a concept--tests to be run were described either by classes containing
* tests or a tree of {@link org.junit.Test}s. However, we want to support filtering and sorting,
* so we need a more abstract specification than the tests themselves and a richer
* specification than just the classes.
*
* <p>The flow when JUnit runs tests is that a <code>Request</code> specifies some tests to be run ->
* a {@link org.junit.runner.Runner} is created for each class implied by the <code>Request</code> ->
* the {@link org.junit.runner.Runner} returns a detailed {@link org.junit.runner.Description}
* which is a tree structure of the tests to be run.
*
* @since 4.0
*/
public abstract class Request {
/**
* Create a <code>Request</code> that, when processed, will run a single test.
* This is done by filtering out all other tests. This method is used to support rerunning
* single tests.
*
* @param clazz the class of the test
* @param methodName the name of the test
* @return a <code>Request</code> that will cause a single test be run
*/
public static Request method(Class<?> clazz, String methodName) {
Description method = Description.createTestDescription(clazz, methodName);
return Request.aClass(clazz).filterWith(method);
}
/**
* Create a <code>Request</code> that, when processed, will run all the tests
* in a class. The odd name is necessary because <code>class</code> is a reserved word.
*
* @param clazz the class containing the tests
* @return a <code>Request</code> that will cause all tests in the class to be run
*/
public static Request aClass(Class<?> clazz) {
return new ClassRequest(clazz);
}
/**
* Create a <code>Request</code> that, when processed, will run all the tests
* in a class. If the class has a suite() method, it will be ignored.
*
* @param clazz the class containing the tests
* @return a <code>Request</code> that will cause all tests in the class to be run
*/
public static Request classWithoutSuiteMethod(Class<?> clazz) {
return new ClassRequest(clazz, false);
}
/**
* Create a <code>Request</code> that, when processed, will run all the tests
* in a set of classes.
*
* @param computer Helps construct Runners from classes
* @param classes the classes containing the tests
* @return a <code>Request</code> that will cause all tests in the classes to be run
*/
public static Request classes(Computer computer, Class<?>... classes) {
try {
AllDefaultPossibilitiesBuilder builder = new AllDefaultPossibilitiesBuilder();
Runner suite = computer.getSuite(builder, classes);
return runner(suite);
} catch (InitializationError e) {
return runner(new ErrorReportingRunner(e, classes));
}
}
/**
* Create a <code>Request</code> that, when processed, will run all the tests
* in a set of classes with the default <code>Computer</code>.
*
* @param classes the classes containing the tests
* @return a <code>Request</code> that will cause all tests in the classes to be run
*/
public static Request classes(Class<?>... classes) {
return classes(JUnitCore.defaultComputer(), classes);
}
/**
* Creates a {@link Request} that, when processed, will report an error for the given
* test class with the given cause.
*/
public static Request errorReport(Class<?> klass, Throwable cause) {
return runner(new ErrorReportingRunner(klass, cause));
}
/**
* @param runner the runner to return
* @return a <code>Request</code> that will run the given runner when invoked
*/
public static Request runner(final Runner runner) {
return new Request() {
@Override
public Runner getRunner() {
return runner;
}
};
}
/**
* Returns a {@link Runner} for this Request
*
* @return corresponding {@link Runner} for this Request
*/
public abstract Runner getRunner();
/**
* Returns a Request that only contains those tests that should run when
* <code>filter</code> is applied
*
* @param filter The {@link Filter} to apply to this Request
* @return the filtered Request
*/
public Request filterWith(Filter filter) {
return new FilterRequest(this, filter);
}
/**
* Returns a Request that only runs tests whose {@link Description}
* matches the given description.
*
* <p>Returns an empty {@code Request} if {@code desiredDescription} is not a single test and filters all but the single
* test if {@code desiredDescription} is a single test.</p>
*
* @param desiredDescription {@code Description} of those tests that should be run
* @return the filtered Request
*/
public Request filterWith(Description desiredDescription) {
return filterWith(Filter.matchMethodDescription(desiredDescription));
}
/**
* Returns a Request whose Tests can be run in a certain order, defined by
* <code>comparator</code>
* <p>
* For example, here is code to run a test suite in alphabetical order:
* <pre>
* private static Comparator<Description> forward() {
* return new Comparator<Description>() {
* public int compare(Description o1, Description o2) {
* return o1.getDisplayName().compareTo(o2.getDisplayName());
* }
* };
* }
*
* public static main() {
* new JUnitCore().run(Request.aClass(AllTests.class).sortWith(forward()));
* }
* </pre>
*
* @param comparator definition of the order of the tests in this Request
* @return a Request with ordered Tests
*/
public Request sortWith(Comparator<Description> comparator) {
return new SortingRequest(this, comparator);
}
/**
* Returns a Request whose Tests can be run in a certain order, defined by
* <code>ordering</code>
* <p>
* For example, here is code to run a test suite in reverse order:
* <pre>
* private static Ordering reverse() {
* return new Ordering() {
* public List<Description> orderItems(Collection<Description> descriptions) {
* List<Description> ordered = new ArrayList<>(descriptions);
* Collections.reverse(ordered);
* return ordered;
* }
* }
* }
*
* public static main() {
* new JUnitCore().run(Request.aClass(AllTests.class).orderWith(reverse()));
* }
* </pre>
*
* @return a Request with ordered Tests
* @since 4.13
*/
public Request orderWith(Ordering ordering) {
return new OrderingRequest(this, ordering);
}
}