With system-rules 1.4.0, JUnit 4.11, and Maven, I got this:

[WARNING] The POM for junit:junit-dep:jar:4.9.1-SNAPSHOT is missing, no dependency information available

To use system-rules with JUnit 4.11, it seems necessary to exclude junit:junit-dep from its dependencies (if using Maven):

    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>com.github.stefanbirkner</groupId>
      <artifactId>system-rules</artifactId>
      <version>1.4.0</version>
      <scope>test</scope>
      <!-- junit:junit-dep is deprecated, and junit:junit replaces it. -->
      <exclusions>
        <exclusion>
          <groupId>junit</groupId>
          <artifactId>junit-dep</artifactId>
        </exclusion>
      </exclusions>
    </dependency>

This works; newer releases of junit:junit seem to have subsumed junit:junit-dep.

I'm not sure what a good solution would be. Shouldn't system-rules depend on junit:junit instead? This is the message included in the junit-dep POM:

The artifact junit:junit does not contain Hamcrest anymore but declares a dependency to Hamcrest. Thus, junit:junit-dep has become obsolete.

Add a new mode, log-on-failure. It should:

• Continue appending to the saved log
• Print to the original streams for failed tests
• This is designed to improve developer convenience, keeping passing tests quiet and making failing tests noisy.

Rebased as suggested. I also squashed some commits to make it clearer what you are getting:

• Commit binkley/system-rules@fb4c976 could be cherry-picked separately; it has PrintStreamLog extends TestWatcher rather than ExternalResource
• Commit binkley/system-rules@cc86caf add log-on-failure mode, requiring previous commit to get at TestWatcher#failed(Throwable, Description).

Cheers, --binkley

With the code below:

exec.execute(new Runnable() {
        public void run() {
            try {
                //
                // It is enough to detect one change to trigger the exit
                // process
                //
                WatchKey k = watcher.take();
            } catch (InterruptedException x) {
                ...
            } finally {
                try {
                    watcher.close();
                    System.exit(EXIT_RESTART);
                } catch (IOException x) {
                    ...
                }
            }
        }
    });

I understand that System.exit(0) throws a security exception, but since it is in a runnable, it does not bubble up.

Using system-rules 1.16 with Junit, Intellij IDEA and Maven It works just fine when I run my test one by one from my IDEA right click menu, say "Run 'testCanNotRestart()'".

But does not work when I run all test methods in the test file, in my case there are other 4 test methods there. Also, it will fail when i run "maven test”.

In the above two fail cases, the SystemOutRule.getLog() just return nothing.

I'm generally quite happy with the stdout/stderr rules. There is one niggle. I prefer "clean" tests - no output in general unless they fail. Would you kindly provide an option in the rules constructor (or a factory method) to not tee output when capturing it? (I do understand this behavior comes from commons-io.)

I'm happy to fork & provide a pull patch to implement, if you wish.

I'm attempting to test a command line runner (based on Spring Batch). Unfortunately, the runner exits rather than, say, returning a value to a trivial wrapper method that exits with that value. In any case, I'd also like to pass data by piping it in through stdin. I can confirm this works in a stand-alone application. However, the mocked data I'm passing into systemInMock doesn't seem to make it to the main method. My code looks something like the following

public class CommandLineRunnerStdInOutTests {

    @Rule
    public final ExpectedSystemExit exit = ExpectedSystemExit.none();

    @Rule
    public final TextFromStandardInputStream systemInMock = emptyStandardInputStream();

    @Rule
    public final StandardOutputStreamLog log = new StandardOutputStreamLog();

    private static final String INPUT_FILE = "data.csv";
    private static final String EXPECTED_FILE = "expected_data.csv";

    @Test
    public void testJob() throws Exception {
        String fileContents = Resources.toString(Resources.getResource(INPUT_FILE), Charsets.UTF_8);
        assertTrue(fileContents.length() >  20);
        systemInMock.provideText(fileContents); // passes: file is read correctly
        exit.expectSystemExitWithStatus(0); // passes: batch job completes, but doesn't see any input records
        CommandLineRunner.main(new String[]{"config.xml", "batchJob"});
    }

    @Test
    public void testFileOut() throws Exception {
        String fileContents = Resources.toString(Resources.getResource(EXPECTED_FILE), Charsets.UTF_8);
        assertEquals(fileContents, log.getLog()); // fails because log.getLog() returns empty String
    }
}

Thanks for writing such an awesome tool! Even with this issue, it has still helped me tremendously!

I would like to test some code that writes raw binary data to stdout. To do so I believe I need access to the underlying byte array, since a sequence of bytes may not be a valid string. Therefore I suggest to add a method getLogBytes to SystemOutRule and SystemErrRule. Let me know if you think this makes sense and if so I will add documentation and tests to this PR.

Hi, I've coded a log-on-failure mode which is similar to log-only however will log to the standard stream for failed tests. This seems to capture the best of worlds:

• Passing tests are quiet and do not log to stream
• Failing tests are noisy and do log to stream

I have a fork with these changes. Would you like a pull request?

https://github.com/binkley/system-rules

Cheers, --binkley

I use the system-rules in some framework dependent projects to test "untestable" things. As Java 9 is approaching quickly I was wondering if system-rules can be used with it, especially that there is a lot of "hack" used to do the things.

I wanted to give it a try, but it seems there are some Maven plugins required to be upgraded (probably the same as some libraries) I decided to just create that issue to consider checking that compatibility one sunny day.

If some of the environment variable values to set are known statically, then let the user set these immediately when instantiating the rule, reducing the need for setup methods.

While creating unit tests to handle some command line output and exceptions thrown in an application, I decided to use SystemErrRule and SystemOutRule to assist with this.

As this particular test is for the main entry point of the application, it is parsing the command line and calling System.exit(1) when invalid command line arguments have been provided.

However, including both of these causes Gradle to throw an exception when trying to run the task gradlew test:

:test
Unexpected exception thrown.
org.gradle.messaging.remote.internal.MessageIOException: Could not read message from '/127.0.0.1:50239'.
        at org.gradle.messaging.remote.internal.inet.SocketConnection.receive(SocketConnection.java:79)
        at org.gradle.messaging.remote.internal.hub.MessageHub$ConnectionReceive.run(MessageHub.java:235)
        at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:54)
        at org.gradle.internal.concurrent.StoppableExecutorImpl$1.run(StoppableExecutorImpl.java:40)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
        at java.lang.Thread.run(Unknown Source)
Caused by: com.esotericsoftware.kryo.KryoException: java.io.IOException: An existing connection was forcibly closed by the remote host
        at com.esotericsoftware.kryo.io.Input.fill(Input.java:141)
        at com.esotericsoftware.kryo.io.Input.require(Input.java:159)
        at com.esotericsoftware.kryo.io.Input.readByte(Input.java:255)
        at org.gradle.internal.serialize.kryo.KryoBackedDecoder.readByte(KryoBackedDecoder.java:80)
        at org.gradle.messaging.remote.internal.hub.InterHubMessageSerializer$MessageReader.read(InterHubMessageSerializer.java:69)
        at org.gradle.messaging.remote.internal.hub.InterHubMessageSerializer$MessageReader.read(InterHubMessageSerializer.java:58)
        at org.gradle.messaging.remote.internal.inet.SocketConnection.receive(SocketConnection.java:74)
        ... 6 more
Caused by: java.io.IOException: An existing connection was forcibly closed by the remote host
        at sun.nio.ch.SocketDispatcher.read0(Native Method)
        at sun.nio.ch.SocketDispatcher.read(Unknown Source)
        at sun.nio.ch.IOUtil.readIntoNativeBuffer(Unknown Source)
        at sun.nio.ch.IOUtil.read(Unknown Source)
        at sun.nio.ch.SocketChannelImpl.read(Unknown Source)
        at org.gradle.messaging.remote.internal.inet.SocketConnection$SocketInputStream.read(SocketConnection.java:158)
        at com.esotericsoftware.kryo.io.Input.fill(Input.java:139)
        ... 12 more
Unexpected exception thrown.
org.gradle.messaging.remote.internal.MessageIOException: Could not write message [EndOfStream] to '/127.0.0.1:50239'.
        at org.gradle.messaging.remote.internal.inet.SocketConnection.dispatch(SocketConnection.java:106)
        at org.gradle.messaging.remote.internal.hub.MessageHub$ConnectionDispatch.run(MessageHub.java:284)
        at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:54)
        at org.gradle.internal.concurrent.StoppableExecutorImpl$1.run(StoppableExecutorImpl.java:40)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
        at java.lang.Thread.run(Unknown Source)
Caused by: java.io.IOException: An existing connection was forcibly closed by the remote host
        at sun.nio.ch.SocketDispatcher.write0(Native Method)
        at sun.nio.ch.SocketDispatcher.write(Unknown Source)
        at sun.nio.ch.IOUtil.writeFromNativeBuffer(Unknown Source)
        at sun.nio.ch.IOUtil.write(Unknown Source)
        at sun.nio.ch.SocketChannelImpl.write(Unknown Source)
        at org.gradle.messaging.remote.internal.inet.SocketConnection$SocketOutputStream.flush(SocketConnection.java:221)
        at org.gradle.messaging.remote.internal.inet.SocketConnection.dispatch(SocketConnection.java:104)
        ... 6 more
:test FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':test'.
> Process 'Gradle Test Executor 1' finished with non-zero exit value 1

In IntelliJ, trying to run this test results in the error response "Failed to start: 0 passed, 1 not started" - so it isn't isolated to Gradle.

Here is an example setup that can reproduce this issue:

Program.java:

package org.test.example;

public final class Program
{
   public static void main(String[] args)
   {
      if (args.length != 2)
      {
         System.out.println("Proper usage: -port <number>");

         System.exit(1);
      }
   }
}

ProgramTest.java:

package org.test.example;

import org.junit.Rule;
import org.junit.Test;
import org.junit.contrib.java.lang.system.ExpectedSystemExit;
import org.junit.contrib.java.lang.system.SystemErrRule;
import org.junit.contrib.java.lang.system.SystemOutRule;
import org.junit.runner.RunWith;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;

@RunWith(PowerMockRunner.class)
@PrepareForTest(Program.class)
public class ProgramTest
{
   /** Handles System.exit() calls. */
   @Rule
   private final ExpectedSystemExit exit = ExpectedSystemExit.none();

   /** Handles System.err calls. */
   @Rule
   private final SystemErrRule err = new SystemErrRule().enableLog().muteForSuccessfulTests();

   /** Handles System.out calls. */
   @Rule
   private final SystemOutRule out = new SystemOutRule().enableLog().muteForSuccessfulTests();

   /**
    * Verify server does not run when only a single valid command line
    * parameter is provided.
    *
    * @throws Exception On error.
    */
   @Test
   public void testMainOneParameterPort() throws Exception
   {
      expectExit();

      Program.main(new String[] { "-port" });
   }

   /**
    * Helper function to setup System.exit() expectations
    */
   private void expectExit()
   {
      exit.expectSystemExitWithStatus(1);

      exit.checkAssertionAfterwards(() ->
      {
         assertFalse(out.getLog().isEmpty());
         assertTrue(err.getLog().isEmpty());
      });
   }
}

Environment Configuration:

Windows 10 Pro x64 10.0.10586

Oracle JDK/JRE x64 1.8.0_66

Gradle 2.5

JUnit 4.12
System Rules 1.15.1
Mockito 1.10.19
PowerMock 1.6.4

I have a test dependent of environment variables. I am setting environment variable in @Before like this.

    @Rule
    public final EnvironmentVariables environmentVariables = new EnvironmentVariables();

@Before
    public void setUp() throws Exception {
        environmentVariables.set("someValue","testLink");
    }

In one of the test I need to clear the same environment variable. But when I do this:

environmentVariables.clear("someValue");

When I run the test alone it works fine but when I run all the tests in the class, environment variable is not cleared. Probably I am missin something but it can be a bug as well.

Under jdk-18 I get a UnsupportedOperationException:

java.lang.UnsupportedOperationException: The Security Manager is deprecated and will be removed in a future release

	at java.base/java.lang.System.setSecurityManager(System.java:416)
	at org.junit.contrib.java.lang.system.ProvideSecurityManager.before(ProvideSecurityManager.java:39)
	at org.junit.rules.ExternalResource$1.evaluate(ExternalResource.java:50)
	at org.junit.contrib.java.lang.system.internal.PrintStreamRule$1$1.evaluate(PrintStreamRule.java:39)
	at org.junit.contrib.java.lang.system.internal.PrintStreamHandler$3.evaluate(PrintStreamHandler.java:44)
	at org.junit.contrib.java.lang.system.internal.PrintStreamRule$1.evaluate(PrintStreamRule.java:35)
	at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
	at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:366)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:63)
	at org.junit.runners.ParentRunner$4.run(ParentRunner.java:331)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:79)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:329)
	at org.junit.runners.ParentRunner.access$100(ParentRunner.java:66)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:293)
	at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:413)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:220)
	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:53)

Per (https://snyk.io/vuln/maven:junit:junit) more details about my particular issue here (https://stackoverflow.com/questions/67165571/why-wont-maven-exclude-test-dependency-even-when-in-exclusion)

Either way a version should be released ASAP with this updated

My first problem is that this package refers maven 4.9and 4.11

4.9:

		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit-dep</artifactId>
			<version>[4.9,)</version>
		</dependency>

I don't see a direct link to 4.11 but I get compilation errors with my own code where maven tells me that there is version conflict with junit 4.12 that I use

FAIK 4.12 is the latest. Can this library be updated?

I tried to fix this myself but the library does not even build. When I try to do mvn install I immediately get a prompt for my PGP password. I have no clue why, your pom does not contain any ref to GPG but probably some parent does... Anyway PGP stuff on my machine is strictly prohibited for access. So the build fails there.

Can these issues be fixed? I'd like

• that system-library uses the latest junit version (4.12 at this moment)
• That the library builds (mvn install) without prompting for any passwords.

to remove e.g.:

[WARNING] The artifact junit:junit-dep:jar:4.11-beta-1 has been relocated to junit:junit:jar:4.11-beta-1

when building.

This also helps me remove a classpath conflict in a project that uses both system-rules and junit (4:12 in my case):

'junit/extensions/ActiveTestSuite$1.class' is present in both 'junit-4.12.jar' and 'junit-dep-4.11.20120805.1225.jar'