fix: handle case where Future.cause() is null in FutureGroup (#52)

carrot

@@ -72,7 +72,7 @@ function java_client_get_next_version()
     esac
 
     if [ ${versions[2]} == "SNAPSHOT" ]; then
-        echo ${versions[0]}.${versions[1]}.SNAPSHOT-$staging_branch
+        echo ${versions[0]}.${versions[1]}-$staging_branch-SNAPSHOT
     else
         echo ${versions[0]}.${versions[1]}.${versions[2]}-$staging_branch
     fi
@@ -282,7 +282,6 @@ function release_minor
     carrot_execute "mvn versions:set -DnewVersion=$new_version"
     carrot_execute "mvn versions:commit"
     carrot_execute "git commit -am \"Bump version to $new_version\""
-    carrot_execute "git push -u origin $this_branch"
 }
 
 function usage_carrot

src/main/java/com/xiaomi/infra/pegasus/client/FutureGroup.java

@@ -37,6 +37,11 @@ void waitAllCompleteOrOneFail(List<Result> results, int timeoutMillis) throws PE
         }
       } else {
         Throwable cause = fu.cause();
+        if (cause == null) {
+          throw new PException(
+              String.format(
+                  "async task #[" + i + "] failed: timeout expired (%dms)", timeoutMillis));
+        }
         throw new PException("async task #[" + i + "] failed: " + cause.getMessage(), cause);
       }
     }

src/test/java/com/xiaomi/infra/pegasus/client/TestFutureGroup.java

@@ -8,10 +8,14 @@
 import java.util.concurrent.Executors;
 import java.util.concurrent.atomic.AtomicBoolean;
 import org.junit.Assert;
+import org.junit.Rule;
 import org.junit.Test;
+import org.junit.rules.TestName;
 
 public class TestFutureGroup {
 
+  @Rule public TestName name = new TestName();
+
   private static final class TestEventExecutor extends SingleThreadEventExecutor {
     TestEventExecutor() {
       super(null, Executors.defaultThreadFactory(), false);
@@ -46,7 +50,7 @@ public void testBlockingOperationException() throws Exception {
             group.waitAllCompleteOrOneFail(10000);
           } catch (PException e) {
             success.set(false);
-            System.err.println("TestFutureGroup.testInterrupt: " + e.toString());
+            System.err.println(name.getMethodName() + ": " + e.toString());
           }
           executed.set(true);
         });
@@ -64,4 +68,22 @@ public void testBlockingOperationException() throws Exception {
 
     Assert.assertFalse(success.get());
   }
+
+  @Test
+  public void testFutureWaitTimeout() throws Exception {
+    TestEventExecutor executor = new TestEventExecutor();
+    Promise<Void> promise = executor.newPromise();
+
+    FutureGroup<Void> group = new FutureGroup<>(1);
+    group.add(promise);
+    try {
+      // never wake up promise.
+      group.waitAllCompleteOrOneFail(10);
+    } catch (PException e) {
+      // must throw exception
+      System.err.println(name.getMethodName() + ": " + e.toString());
+      return;
+    }
+    Assert.fail();
+  }
 }