Execute platform-dependent test using JUnit4

BlockJunit4ClassRunner.java

    @Override
    protected void runChild(FrameworkMethod method, RunNotifier notifier) {
        EachTestNotifier eachNotifier= makeNotifier(method, notifier);
        if (method.getAnnotation(Ignore.class) != null) {
            runIgnored(eachNotifier);
        } else {
            runNotIgnored(method, eachNotifier);
        }
    }

    private void runNotIgnored(FrameworkMethod method,
        EachTestNotifier eachNotifier) {
        eachNotifier.fireTestStarted();
        try {
            methodBlock(method).evaluate();
        } catch (AssumptionViolatedException e) {
            eachNotifier.addFailedAssumption(e);
        } catch (Throwable e) {
            eachNotifier.addFailure(e);
        } finally {
            eachNotifier.fireTestFinished();
        }
    }

CustomJUnit4ClassRunner.java

package extensions;

import org.junit.Ignore;
import org.junit.internal.AssumptionViolatedException;
import org.junit.internal.runners.model.EachTestNotifier;
import org.junit.runner.Description;
import org.junit.runner.notification.RunNotifier;
import org.junit.runners.BlockJUnit4ClassRunner;
import org.junit.runners.model.FrameworkMethod;
import org.junit.runners.model.InitializationError;

public class CustomJUnit4ClassrRunner extends BlockJUnit4ClassRunner {

    private static Platform thisMachinesPlatform;
    static {
        String osName = System.getProperty("os.name").toLowerCase();

        if (osName.startsWith("windows")) {
            thisMachinesPlatform = Platform.WINDOWS;
        } else {
            thisMachinesPlatform = Platform.UNIX;
        }
    }

    public CustomJUnit4ClassrRunner(Class<?> klass) throws InitializationError {
        super(klass);
    }

    @Override
    protected void runChild(FrameworkMethod method, RunNotifier notifier) {
        EachTestNotifier eachNotifier = makeNotifier(method, notifier);
        if (method.getAnnotation(Ignore.class) != null) {
            runIgnored(eachNotifier);
        } else {
            DependsOnPlatform dependsOnPlatform = method.getAnnotation(DependsOnPlatform.class);
            if (dependsOnPlatform != null && dependsOnPlatform.platform() != thisMachinesPlatform) {
                runIgnored(eachNotifier);
                return;
            }
            runNotIgnored(method, eachNotifier);
        }
    }

    // copy of BlockJUnit4ClassRunner#runNotIgnored
    private void runNotIgnored(FrameworkMethod method, EachTestNotifier eachNotifier) {
        eachNotifier.fireTestStarted();
        try {
            methodBlock(method).evaluate();
        } catch (AssumptionViolatedException e) {
            eachNotifier.addFailedAssumption(e);
        } catch (Throwable e) {
            eachNotifier.addFailure(e);
        } finally {
            eachNotifier.fireTestFinished();
        }
    }

    // copy of BlockJUnit4ClassRunner#runIgnored
    private void runIgnored(EachTestNotifier eachNotifier) {
        eachNotifier.fireTestIgnored();
    }

    // copy of BlockJUnit4ClassRunner#makeNotifier
    private EachTestNotifier makeNotifier(FrameworkMethod method, RunNotifier notifier) {
        Description description = describeChild(method);
        return new EachTestNotifier(notifier, description);
    }
}

DefaultShellCommandTest.java

package yourdomain.yourapp;

import static org.hamcrest.Matchers.*;
import static org.junit.Assert.*;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.seasar.util.misc.Pair;

import extensions.CustomJUnit4ClassrRunner;
import extensions.DependsOnPlatform;
import extensions.Platform;

@RunWith(CustomJUnit4ClassrRunner.class)
public class ShellCommandTest {

    private ShellCommand command = new DefaultShellCommand();

    @Test
    @DependsOnPlatform(platform = Platform.UNIX)
    public void unix_likeな環境でのみ動くテスト() {
        Pair<Integer, String> result = command.exec("echo", "foobar");

        assertThat(result.getFirst(), is(0));
        assertThat(result.getSecond(), is("foobar"));
    }

    @Test
    @DependsOnPlatform(platform = Platform.WINDOWS)
    public void windows環境でのみ動くテスト() {
        Pair<Integer, String> result = command.exec("echo", "foobar");

        assertThat(result.getFirst(), is(0));
        assertThat(result.getSecond(), is("foobar\r\n"));
    }
}

DependsOnPlatform.java

package extensions;

import java.lang.annotation.Retention;
import static java.lang.annotation.RetentionPolicy.*;

@Retention(RUNTIME)
public @interface DependsOnPlatform {
    Platform platform();
}

Platform.java

package extensions;

public enum Platform {
    UNIX, WINDOWS;
}