Merge pull request #1740 from junit-team/marc/1739-fix-compile-error-on-jdk-18

Fix compile error on JDK 18 and later

Author: kcooney

.github/workflows/main.yml

@@ -16,7 +16,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        java: ['6', '8', '11', '17']
+        java: ['6', '8', '11', '17', '18']
     steps:
       - uses: actions/checkout@v2
       - name: Download Maven # Download with default JDK because OpenJDK 6 does not support TLS 1.2

pom.xml

@@ -262,7 +262,9 @@
                 <artifactId>maven-surefire-plugin</artifactId>
                 <version>${surefireVersion}</version>
                 <configuration>
-                    <test>org/junit/tests/AllTests.java</test>
+                    <includes>
+                        <include>org/junit/tests/AllTests.java</include>
+                    </includes>
                     <useSystemClassLoader>true</useSystemClassLoader>
                     <enableAssertions>false</enableAssertions>
                 </configuration>

src/main/java/org/junit/runner/JUnitCore.java

@@ -33,8 +33,12 @@ public class JUnitCore {
      * @param args names of classes in which to find tests to run
      */
     public static void main(String... args) {
+        System.exit(runMain(args));
+    }
+
+    static int runMain(String[] args) {
         Result result = new JUnitCore().runMain(new RealSystem(), args);
-        System.exit(result.wasSuccessful() ? 0 : 1);
+        return result.wasSuccessful() ? 0 : 1;
     }
 
     /**

src/main/java/org/junit/runner/Result.java

@@ -188,7 +188,7 @@ public SerializedForm(Result result) {
         }
 
         @SuppressWarnings("unchecked")
-        private SerializedForm(ObjectInputStream.GetField fields) throws IOException {
+        private SerializedForm(ObjectInputStream.GetField fields) throws IOException, ClassNotFoundException {
             fCount = (AtomicInteger) fields.get("fCount", null);
             fIgnoreCount = (AtomicInteger) fields.get("fIgnoreCount", null);
             assumptionFailureCount = (AtomicInteger) fields.get("assumptionFailureCount", null);

src/test/java/org/junit/runner/MainRunner.java

@@ -0,0 +1,23 @@
+package org.junit.runner;
+
+import java.io.OutputStream;
+import java.io.PrintStream;
+
+public class MainRunner {
+
+    public static int runMain(String... args) {
+        PrintStream oldOut = System.out;
+        System.setOut(new PrintStream(new NullOutputStream()));
+        try {
+            return JUnitCore.runMain(args);
+        } finally {
+            System.setOut(oldOut);
+        }
+    }
+
+    static class NullOutputStream extends OutputStream {
+        public void write(int b) {
+            // do nothing
+        }
+    }
+}

src/test/java/org/junit/tests/running/core/CommandLineTest.java

@@ -10,6 +10,7 @@
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.JUnitCore;
+import org.junit.runner.MainRunner;
 
 public class CommandLineTest {
     private ByteArrayOutputStream results;
@@ -38,11 +39,7 @@ public void test() {
     @Test
     public void runATest() {
         testWasRun = false;
-        new MainRunner().runWithCheckForSystemExit(new Runnable() {
-            public void run() {
-                JUnitCore.main("org.junit.tests.running.core.CommandLineTest$Example");
-            }
-        });
+        MainRunner.runMain(Example.class.getName());
         assertTrue(testWasRun);
     }
 

src/test/java/org/junit/tests/running/core/JUnitCoreReturnsCorrectExitCodeTest.java

@@ -4,7 +4,7 @@
 import static org.junit.Assert.fail;
 
 import org.junit.Test;
-import org.junit.runner.JUnitCore;
+import org.junit.runner.MainRunner;
 
 public class JUnitCoreReturnsCorrectExitCodeTest {
 
@@ -37,11 +37,7 @@ public void successCausesExitCodeOf0() throws Exception {
     }
 
     private void runClass(final String className, int returnCode) {
-        Integer exitValue = new MainRunner().runWithCheckForSystemExit(new Runnable() {
-            public void run() {
-                JUnitCore.main(className);
-            }
-        });
-        assertEquals(Integer.valueOf(returnCode), exitValue);
+        int exitValue = MainRunner.runMain(className);
+        assertEquals(returnCode, exitValue);
     }
 }