(helix) branch master updated: Prevent MetaClient LeaderElectionClient isLeader NPE before joining pool (#2798)

[xyuanlu]

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xyuanlu pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/helix.git


The following commit(s) were added to refs/heads/master by this push:
     new 1bfed3138 Prevent MetaClient LeaderElectionClient isLeader NPE before 
joining pool (#2798)
1bfed3138 is described below

commit 1bfed3138a93c7e4a4bcc48349ce11b249167926
Author: Grant Paláu Spencer <gspen...@linkedin.com>
AuthorDate: Tue May 7 11:57:28 2024 -0700

    Prevent MetaClient LeaderElectionClient isLeader NPE before joining pool 
(#2798)
    
    Prevent MetaClient LeaderElectionClient isLeader NPE before joining pool
---
 .../recipes/leaderelection/LeaderElectionClient.java       |  3 ++-
 .../recipes/leaderelection/TestLeaderElection.java         | 14 ++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git 
a/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionClient.java
 
b/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionClient.java
index 3bcf09ceb..373d36013 100644
--- 
a/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionClient.java
+++ 
b/meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionClient.java
@@ -121,7 +121,8 @@ public class LeaderElectionClient implements AutoCloseable {
    * Returns true if current participant is the current leadership.
    */
   public boolean isLeader(String leaderPath) {
-    return getLeader(leaderPath).equalsIgnoreCase(_participant);
+    String leader = getLeader(leaderPath);
+    return leader != null && leader.equalsIgnoreCase(_participant);
   }
 
   /**
diff --git 
a/meta-client/src/test/java/org/apache/helix/metaclient/recipes/leaderelection/TestLeaderElection.java
 
b/meta-client/src/test/java/org/apache/helix/metaclient/recipes/leaderelection/TestLeaderElection.java
index 75917623c..248643652 100644
--- 
a/meta-client/src/test/java/org/apache/helix/metaclient/recipes/leaderelection/TestLeaderElection.java
+++ 
b/meta-client/src/test/java/org/apache/helix/metaclient/recipes/leaderelection/TestLeaderElection.java
@@ -41,7 +41,21 @@ public class TestLeaderElection extends ZkMetaClientTestBase 
{
     }
   }
 
+  // Test that calling isLeader before client joins 
LeaderElectionParticipantPool returns false and does not throw NPE
   @Test
+  public void testIsLeaderBeforeJoiningParticipantPool() throws Exception {
+    String leaderPath = LEADER_PATH + "/testIsLeaderBeforeJoiningPool";
+    LeaderElectionClient clt1 = createLeaderElectionClient(PARTICIPANT_NAME1);
+    try {
+      boolean isLeader = clt1.isLeader(leaderPath);
+      Assert.assertFalse(isLeader, "Expected isLeader to return false before 
joining participant pool");
+    } catch (NullPointerException npe) {
+      Assert.fail("isLeader threw NPE before joining participant pool: " + 
npe.getMessage());
+    }
+    clt1.close();
+  }
+
+  @Test (dependsOnMethods = "testIsLeaderBeforeJoiningParticipantPool")
   public void testAcquireLeadership() throws Exception {
     System.out.println("START TestLeaderElection.testAcquireLeadership");
     String leaderPath = LEADER_PATH + "/testAcquireLeadership";