allow unit tests to run in a new thread

Signed-off-by: Ceki Gulcu <ceki@qos.ch>

slf4j-api/src/test/java/org/slf4j/rule/BlaTest.java

@@ -0,0 +1,38 @@
+package org.slf4j.rule;
+
+import static org.junit.Assert.fail;
+
+import org.junit.Ignore;
+import org.junit.Rule;
+import org.junit.Test;
+
+@Ignore // this test has intentional fails
+public class BlaTest {
+
+    @Rule
+    public RunInNewThreadRule runInThread = new RunInNewThreadRule();
+
+    @Test
+    public void aTest() {
+        System.out.println("running aTest in "+ Thread.currentThread().getName());
+    }
+    
+    @RunInNewThread
+    @Test
+    public void bTest() {
+        System.out.println("running bTest in "+ Thread.currentThread().getName());
+    }
+  
+    @RunInNewThread(timeout = 2000L)
+    @Test
+    public void cTest() {
+        System.out.println("running cTest in "+ Thread.currentThread().getName());
+    }
+    @RunInNewThread()
+    @Test
+    public void dTest() {
+        System.out.println("running dTest in "+ Thread.currentThread().getName());
+        fail();
+    }
+}
+

slf4j-api/src/test/java/org/slf4j/rule/RunInNewThread.java

@@ -0,0 +1,39 @@
+/**
+ * Copyright (c) 2021 QOS.ch
+ * All rights reserved.
+ *
+ * Permission is hereby granted, free  of charge, to any person obtaining
+ * a  copy  of this  software  and  associated  documentation files  (the
+ * "Software"), to  deal in  the Software without  restriction, including
+ * without limitation  the rights to  use, copy, modify,  merge, publish,
+ * distribute,  sublicense, and/or sell  copies of  the Software,  and to
+ * permit persons to whom the Software  is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The  above  copyright  notice  and  this permission  notice  shall  be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE  SOFTWARE IS  PROVIDED  "AS  IS", WITHOUT  WARRANTY  OF ANY  KIND,
+ * EXPRESS OR  IMPLIED, INCLUDING  BUT NOT LIMITED  TO THE  WARRANTIES OF
+ * MERCHANTABILITY,    FITNESS    FOR    A   PARTICULAR    PURPOSE    AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE,  ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+package org.slf4j.rule;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.METHOD})
+public @interface RunInNewThread {
+    static final long DEFAULT_TIMEOUT = 1000L;
+    public long timeout() default DEFAULT_TIMEOUT;
+}

slf4j-api/src/test/java/org/slf4j/rule/RunInNewThreadRule.java

@@ -0,0 +1,54 @@
+/**
+ * Copyright (c) 2021 QOS.ch
+ * All rights reserved.
+ *
+ * Permission is hereby granted, free  of charge, to any person obtaining
+ * a  copy  of this  software  and  associated  documentation files  (the
+ * "Software"), to  deal in  the Software without  restriction, including
+ * without limitation  the rights to  use, copy, modify,  merge, publish,
+ * distribute,  sublicense, and/or sell  copies of  the Software,  and to
+ * permit persons to whom the Software  is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The  above  copyright  notice  and  this permission  notice  shall  be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE  SOFTWARE IS  PROVIDED  "AS  IS", WITHOUT  WARRANTY  OF ANY  KIND,
+ * EXPRESS OR  IMPLIED, INCLUDING  BUT NOT LIMITED  TO THE  WARRANTIES OF
+ * MERCHANTABILITY,    FITNESS    FOR    A   PARTICULAR    PURPOSE    AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE,  ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+package org.slf4j.rule;
+
+import org.junit.rules.TestRule;
+import org.junit.runner.Description;
+import org.junit.runners.model.Statement;
+
+// This class has been inspired by the article "A JUnit Rule to Run a Test in Its Own Thread"
+// published by Frank Appel, author of the book "Testing with JUnit" published by Packt publishing. 
+// 
+// See also
+// https://www.codeaffine.com/2014/07/21/a-junit-rule-to-run-a-test-in-its-own-thread/
+    
+public class RunInNewThreadRule implements TestRule {
+
+    @Override
+    public Statement apply(Statement base, Description description) {
+        RunInNewThread desiredAnnotaton = description.getAnnotation(RunInNewThread.class);
+        
+        if(desiredAnnotaton ==  null) {
+            System.out.println("test "+ description.getMethodName() +" not annotated");
+            return base;
+        } else {
+            long timeout = desiredAnnotaton.timeout();
+            System.out.println("running "+ description.getMethodName() +" in separate tjread");
+            return new RunInNewThreadStatement(base, timeout);
+        }
+    }
+
+}

slf4j-api/src/test/java/org/slf4j/rule/RunInNewThreadStatement.java

@@ -0,0 +1,68 @@
+/**
+ * Copyright (c) 2021 QOS.ch
+ * All rights reserved.
+ *
+ * Permission is hereby granted, free  of charge, to any person obtaining
+ * a  copy  of this  software  and  associated  documentation files  (the
+ * "Software"), to  deal in  the Software without  restriction, including
+ * without limitation  the rights to  use, copy, modify,  merge, publish,
+ * distribute,  sublicense, and/or sell  copies of  the Software,  and to
+ * permit persons to whom the Software  is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The  above  copyright  notice  and  this permission  notice  shall  be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE  SOFTWARE IS  PROVIDED  "AS  IS", WITHOUT  WARRANTY  OF ANY  KIND,
+ * EXPRESS OR  IMPLIED, INCLUDING  BUT NOT LIMITED  TO THE  WARRANTIES OF
+ * MERCHANTABILITY,    FITNESS    FOR    A   PARTICULAR    PURPOSE    AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE,  ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ */
+package org.slf4j.rule;
+
+import org.junit.runners.model.Statement;
+
+//This class has been inspired by the article "A JUnit Rule to Run a Test in Its Own Thread"
+//published by Frank Appel, author of the book "Testing with JUnit" published by Packt publishing. 
+//
+//See also
+//https://www.codeaffine.com/2014/07/21/a-junit-rule-to-run-a-test-in-its-own-thread/
+
+public class RunInNewThreadStatement extends Statement implements Runnable {
+
+    final Statement base;
+    final long timeout;
+    Throwable throwable;
+    
+    RunInNewThreadStatement(Statement base, long timeout) {
+        this.base = base;
+        this.timeout = timeout;
+    }
+    
+    @Override
+    public void evaluate() throws Throwable {
+       Thread thread = new Thread(this);
+       thread.start();
+       System.out.println("Timeout is "+timeout);
+       thread.join(timeout);
+       
+       if(throwable != null) {
+           throw throwable;
+       }
+    }
+
+    @Override
+    public void run() {
+        try {
+            base.evaluate();
+        } catch (Throwable e) {
+            this.throwable = e;
+        }
+    }
+
+    
+}