(kafka) branch trunk updated: MINOR: Fix KStream leftJoin doc and test param naming for KStream-GlobalKTable (#22889)

[mjsax]

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mjsax pushed a commit to branch trunk
in repository https://gitbox.apache.org/repos/asf/kafka.git


The following commit(s) were added to refs/heads/trunk by this push:
     new 3c257464fe4 MINOR: Fix KStream leftJoin doc and test param naming for 
KStream-GlobalKTable  (#22889)
3c257464fe4 is described below

commit 3c257464fe4c2e83d85c13d611546e28f09f967c
Author: Lucy Liu <luc...@confluent.io>
AuthorDate: Wed Jul 22 12:04:21 2026 -0500

    MINOR: Fix KStream leftJoin doc and test param naming for 
KStream-GlobalKTable  (#22889)
    
    This PR fixes:
    - Wrong description regarding leftJoin(GlobalKTable, ...) Javadoc when
    keySelector is null
    - Wrong param ordering for ValueJoinerWithStreamAndMappedKey for 2 unit
    tests
    
    Reviewers: Matthias J. Sax <matth...@confluent.io>
---
 streams/src/main/java/org/apache/kafka/streams/kstream/KStream.java | 6 ++++--
 .../streams/kstream/internals/KStreamGlobalKTableJoinTest.java      | 2 +-
 .../streams/kstream/internals/KStreamGlobalKTableLeftJoinTest.java  | 2 +-
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git 
a/streams/src/main/java/org/apache/kafka/streams/kstream/KStream.java 
b/streams/src/main/java/org/apache/kafka/streams/kstream/KStream.java
index d532880de90..c9dc6847cfe 100644
--- a/streams/src/main/java/org/apache/kafka/streams/kstream/KStream.java
+++ b/streams/src/main/java/org/apache/kafka/streams/kstream/KStream.java
@@ -1433,8 +1433,10 @@ public interface KStream<K, V> {
      * or the {@code KStreams} input record's key for a left-join result.
      * If you need read access to the {@code KStream} key or the {@link 
GlobalKTable} key (which is the same as the
      * join key extracted by {@code keySelector}), use {@link 
#leftJoin(GlobalKTable, KeyValueMapper, ValueJoinerWithStreamAndMappedKey)}.
-     * If a {@code KStream} input record's value is {@code null} or if the 
provided {@link KeyValueMapper keySelector}
-     * returns {@code null}, the input record will be dropped, and no join 
computation is triggered.
+     * If a {@code KStream} input record's value is {@code null}, the input 
record will be dropped,
+     * and no join computation is triggered.
+     * If the provided {@link KeyValueMapper keySelector} returns {@code 
null}, the record will be treated as a non-match
+     * and {@link ValueJoiner} will be called with a {@code null} value for 
the global table record.
      * Note, that {@code null} keys for {@code KStream} input records are 
supported (in contrast to
      * {@link #join(GlobalKTable, KeyValueMapper, ValueJoiner) inner join}) 
resulting in a left join result.
      * If a {@link GlobalKTable} input record's key is {@code null} the input 
record will be dropped, and the table
diff --git 
a/streams/src/test/java/org/apache/kafka/streams/kstream/internals/KStreamGlobalKTableJoinTest.java
 
b/streams/src/test/java/org/apache/kafka/streams/kstream/internals/KStreamGlobalKTableJoinTest.java
index d9a560e5635..9e253ebb0de 100644
--- 
a/streams/src/test/java/org/apache/kafka/streams/kstream/internals/KStreamGlobalKTableJoinTest.java
+++ 
b/streams/src/test/java/org/apache/kafka/streams/kstream/internals/KStreamGlobalKTableJoinTest.java
@@ -438,7 +438,7 @@ public class KStreamGlobalKTableJoinTest {
             table,
             (KeyValueMapper<Integer, String, String>) (k, v) -> v,
             (ValueJoinerWithStreamAndMappedKey<Integer, String, String, 
String, String>)
-                (mk, sk, v1, v2) -> v1 + v2,
+                (streamKey, mappedKey, v1, v2) -> v1 + v2,
             Named.as("join-table"));
         assertThat(builder.build().describe().toString(), 
containsString("Processor: join-table"));
     }
diff --git 
a/streams/src/test/java/org/apache/kafka/streams/kstream/internals/KStreamGlobalKTableLeftJoinTest.java
 
b/streams/src/test/java/org/apache/kafka/streams/kstream/internals/KStreamGlobalKTableLeftJoinTest.java
index ea3e07010b1..8a8f88e10f5 100644
--- 
a/streams/src/test/java/org/apache/kafka/streams/kstream/internals/KStreamGlobalKTableLeftJoinTest.java
+++ 
b/streams/src/test/java/org/apache/kafka/streams/kstream/internals/KStreamGlobalKTableLeftJoinTest.java
@@ -506,7 +506,7 @@ public class KStreamGlobalKTableLeftJoinTest {
         stream.leftJoin(
             table,
             (KeyValueMapper<Integer, String, String>) (k, v) -> v,
-            (ValueJoinerWithStreamAndMappedKey<Integer, String, String, 
String, String>) (mk, sk, v1, v2) -> v1 + v2,
+            (ValueJoinerWithStreamAndMappedKey<Integer, String, String, 
String, String>) (streamKey, mappedKey, v1, v2) -> v1 + v2,
             Named.as("left-join-table"));
 
         assertThat(builder.build().describe().toString(), 
containsString("Processor: left-join-table"));