From c729187e1fddda9643d948ed1b21a920528dffd3 Mon Sep 17 00:00:00 2001
From: Niels Bauman <33722607+nielsbauman@users.noreply.github.com>
Date: Tue, 30 Sep 2025 19:15:59 -0300
Subject: [PATCH] Fix tests in `SetSingleNodeAllocateStepTests` (#135724)

By doing
`VersionUtils.randomCompatibleVersion(random(), VersionUtils.getPreviousVersion())`,
we could also get `Version.CURRENT`, as that version is also compatible
with the previous version (unless we're running right after a major
version was released). If the `oldVersion` variable in these tests is
equal to the current version, the tests will fail as their whole goal is
to verify behavior with different node versions. Instead, we should get a
random version that is at most the previous version, to guarantee that
`oldVersion` always precedes the current version.

Fixes #135590

(cherry picked from commit 712cf9f18985ef655b5508ad51f40cc208acf538)
---
 .../ilm/SetSingleNodeAllocateStepTests.java   | 31 ++++++++++---------
 1 file changed, 16 insertions(+), 15 deletions(-)

diff --git a/x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ilm/SetSingleNodeAllocateStepTests.java b/x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ilm/SetSingleNodeAllocateStepTests.java
index f988a6fd5769c..334ac200850bc 100644
--- a/x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ilm/SetSingleNodeAllocateStepTests.java
+++ b/x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ilm/SetSingleNodeAllocateStepTests.java
@@ -26,6 +26,7 @@
 import org.elasticsearch.common.settings.Settings.Builder;
 import org.elasticsearch.common.transport.TransportAddress;
 import org.elasticsearch.common.util.Maps;
+import org.elasticsearch.env.BuildVersion;
 import org.elasticsearch.index.Index;
 import org.elasticsearch.index.IndexNotFoundException;
 import org.elasticsearch.index.IndexVersion;
@@ -386,11 +387,7 @@ public void testPerformActionAttrsNoShard() {
     }
 
     public void testPerformActionSomeShardsOnlyOnNewNodes() throws Exception {
-        VersionInformation oldVersion = new VersionInformation(
-            VersionUtils.randomCompatibleVersion(random(), VersionUtils.getPreviousVersion()),
-            IndexVersions.MINIMUM_COMPATIBLE,
-            IndexVersionUtils.randomCompatibleVersion(random())
-        );
+        final VersionInformation oldVersion = randomOldVersionInformation();
         final int numNodes = randomIntBetween(2, 20); // Need at least 2 nodes to have some nodes on a new version
         final int numNewNodes = randomIntBetween(1, numNodes - 1);
         final int numOldNodes = numNodes - numNewNodes;
@@ -451,11 +448,7 @@ public void testPerformActionSomeShardsOnlyOnNewNodes() throws Exception {
     }
 
     public void testPerformActionSomeShardsOnlyOnNewNodesButNewNodesInvalidAttrs() {
-        VersionInformation oldVersion = new VersionInformation(
-            VersionUtils.randomCompatibleVersion(random(), VersionUtils.getPreviousVersion()),
-            IndexVersions.MINIMUM_COMPATIBLE,
-            IndexVersionUtils.randomCompatibleVersion(random())
-        );
+        final var oldVersion = randomOldVersionInformation();
         final int numNodes = randomIntBetween(2, 20); // Need at least 2 nodes to have some nodes on a new version
         final int numNewNodes = randomIntBetween(1, numNodes - 1);
         final int numOldNodes = numNodes - numNewNodes;
@@ -524,11 +517,7 @@ public void testPerformActionSomeShardsOnlyOnNewNodesButNewNodesInvalidAttrs() {
     }
 
     public void testPerformActionNewShardsExistButWithInvalidAttributes() throws Exception {
-        VersionInformation oldVersion = new VersionInformation(
-            VersionUtils.randomCompatibleVersion(random(), VersionUtils.getPreviousVersion()),
-            IndexVersions.MINIMUM_COMPATIBLE,
-            IndexVersionUtils.randomCompatibleVersion(random())
-        );
+        final VersionInformation oldVersion = randomOldVersionInformation();
         final int numNodes = randomIntBetween(2, 20); // Need at least 2 nodes to have some nodes on a new version
         final int numNewNodes = randomIntBetween(1, numNodes - 1);
         final int numOldNodes = numNodes - numNewNodes;
@@ -596,6 +585,18 @@ public void testPerformActionNewShardsExistButWithInvalidAttributes() throws Exc
         assertNodeSelected(indexMetadata, indexMetadata.getIndex(), oldNodeIds, discoveryNodes, indexRoutingTable.build());
     }
 
+    private VersionInformation randomOldVersionInformation() {
+        final var previousVersion = VersionUtils.getPreviousVersion();
+        final var version = VersionUtils.randomVersionBetween(random(), previousVersion.minimumCompatibilityVersion(), previousVersion);
+        return new VersionInformation(
+            BuildVersion.fromVersionId(version.id()),
+            version,
+            IndexVersions.MINIMUM_COMPATIBLE,
+            IndexVersions.MINIMUM_COMPATIBLE,
+            IndexVersionUtils.randomCompatibleVersion(random())
+        );
+    }
+
     private Collection<Map.Entry<String, String>> generateRandomValidAttributes(int numAttrs) {
         return generateRandomValidAttributes(numAttrs, "");
     }