From 31209393bc0b587fd8f213cdf3d614e9fa6492a7 Mon Sep 17 00:00:00 2001
From: Purushottam Sinha <psinha@confluent.io>
Date: Thu, 13 Aug 2026 23:51:21 +0530
Subject: [PATCH] [FLINK-40382][build] Stop surefire from hiding nested test
 classes

Surefire's default excludes drop **/*$*, so a test class declared as a
static nested class is never selected. JUnit Jupiter only auto-discovers
@Nested inner classes, so such a class falls through both paths and never
runs, with no log line, report file or skip count to show it.

Override the excludes on the default-test execution. The include pattern
there is name-based (**/*Test.*, **/*Tests.*), so only nested classes whose
name ends in Test/Tests are picked up. The explicit **/*$* exclude on the
integration-tests execution is left alone: its include is **/*.*, which
would otherwise match Scala-generated names such as
TypeInformationGenTest$$anon$85$$anon$86.

This recovers the nested test classes without touching any test code:
flink-table-type-utils goes from 151 to 418 tests, flink-core picks up both
NullableSerializerTest variants (19 each) and flink-runtime picks up
InputSelectionTest$BuilderTest (3).

Of the 152 nested classes that newly match the include, 134 are existing
@Nested classes that already ran (JUnit deduplicates, so they do not run
twice) and 2 are abstract bases that JUnit ignores.

Generated-by: Claude Code (claude-opus-5)
---
 pom.xml | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/pom.xml b/pom.xml
index b67166326c5622..505739dfc11afd 100644
--- a/pom.xml
+++ b/pom.xml
@@ -1824,6 +1824,14 @@ under the License.
 							<includes>
 								<include>${test.unit.pattern}</include>
 							</includes>
+							<excludes>
+								<!-- Overrides surefire's default excludes, which drop **/*$* and
+								     thereby hide every nested test class. The include pattern above
+								     is name-based, so only nested classes ending in Test/Tests are
+								     picked up. Keep this list non-empty; an empty list restores the
+								     defaults. -->
+								<exclude>**/*$*$*.class</exclude>
+							</excludes>
 							<forkCount>${flink.forkCountUnitTest}</forkCount>
 							<argLine>${flink.surefire.baseArgLine} -Xmx${flink.XmxUnitTest}</argLine>
 						</configuration>