test: rmi: Fix compatibility with GraalVM 17.0.9 behavior

While testing GraalVM 17.0.9, selftest failed with a different exception
than expected (instead of a NoSuchObjectException, we get an
IllegalArgumentException with a NoSuchMethodException cause).

Handle this case gracefully to reduce false positive errors in selftest.

Author: kohlschuetter

junixsocket-rmi/src/test/java/org/newsclub/net/unix/rmi/RemoteCloseableTest.java

@@ -18,7 +18,7 @@
 package org.newsclub.net.unix.rmi;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.fail;
 
 import java.io.IOException;
 import java.rmi.NoSuchObjectException;
@@ -60,14 +60,19 @@ public void testRemoteCloseableWithACloseableThing() throws IOException, NotBoun
         remoteCloseable.close();
         assertEquals(1, svc.remoteCloseableThingNumberOfCloseCalls(IsCloseable.class));
 
-        assertThrows(NoSuchObjectException.class, () -> {
-          remoteCloseable.close();
-        });
+        remoteCloseable.close();
+        fail("Should have thrown an exception");
       }
     } catch (NoSuchObjectException e) {
       // expected — since the object was forcibly closed above, it was unexported already.
       // ideally, RMI could gracefully handle calling #close() on an proxy that points to an
       // unexported object.
+    } catch (IllegalArgumentException e) {
+      if (e.getCause() instanceof NoSuchMethodException) {
+        // observed with GraalVM 17.0.9; see java.rmi.server.RemoteObjectInvocationHandler
+      } else {
+        throw e;
+      }
     }
     assertEquals(1, svc.remoteCloseableThingNumberOfCloseCalls(IsCloseable.class));
 
@@ -99,13 +104,18 @@ public void testRemoteCloseableWithANotCloseableThing() throws IOException, NotB
       remoteCloseable.close();
       assertEquals(0, svc.remoteCloseableThingNumberOfCloseCalls(NotCloseable.class));
 
-      assertThrows(NoSuchObjectException.class, () -> {
-        remoteCloseable.close();
-      });
+      remoteCloseable.close();
+      fail("Should have thrown an exception");
     } catch (NoSuchObjectException e) {
       // expected — since the object was forcibly closed above, it was unexported already.
       // ideally, RMI could gracefully handle calling #close() on an proxy that points to an
       // unexported object.
+    } catch (IllegalArgumentException e) {
+      if (e.getCause() instanceof NoSuchMethodException) {
+        // observed with GraalVM 17.0.9; see java.rmi.server.RemoteObjectInvocationHandler
+      } else {
+        throw e;
+      }
     }
     assertEquals(0, svc.remoteCloseableThingNumberOfCloseCalls(NotCloseable.class));
 

src/site/markdown/changelog.md

@@ -17,6 +17,7 @@ artifact (`<type>pom</type>`); see [Add junixsocket to your project](dependency.
 - Fix left-over temporary library files on Windows
 - Fix duplicate file descriptors being received sporadically for non-blocking sockets and upon error
 - Fix a flaky selftest when VSOCK is not supported
+- Fix a flaky selftest with GraalvM 17
 - Improve interoperability with exotic Linux/Java combinations
 - Add support for loongarch64 Linux
 - Add more tests