001package org.junit.runner;
002
003import org.junit.runners.Suite;
004import org.junit.runners.model.InitializationError;
005import org.junit.runners.model.RunnerBuilder;
006
007/**
008 * Represents a strategy for computing runners and suites.
009 * WARNING: this class is very likely to undergo serious changes in version 4.8 and
010 * beyond.
011 *
012 * @since 4.6
013 */
014public class Computer {
015    /**
016     * Returns a new default computer, which runs tests in serial order
017     */
018    public static Computer serial() {
019        return new Computer();
020    }
021
022    /**
023     * Create a suite for {@code classes}, building Runners with {@code builder}.
024     * Throws an InitializationError if Runner construction fails
025     */
026    public Runner getSuite(final RunnerBuilder builder,
027            Class<?>[] classes) throws InitializationError {
028        return new Suite(new RunnerBuilder() {
029            @Override
030            public Runner runnerForClass(Class<?> testClass) throws Throwable {
031                return getRunner(builder, testClass);
032            }
033        }, classes) {
034            @Override
035            protected String getName() {
036                /*
037                 * #1320 The generated suite is not based on a real class so
038                 * only a 'null' description can be generated from it. This name
039                 * will be overridden here.
040                 */
041                return "classes";
042            }
043        };
044    }
045
046    /**
047     * Create a single-class runner for {@code testClass}, using {@code builder}
048     */
049    protected Runner getRunner(RunnerBuilder builder, Class<?> testClass) throws Throwable {
050        return builder.runnerForClass(testClass);
051    }
052}