From e151c10e76d86fbe38bc5c77064b8c91db6b650f Mon Sep 17 00:00:00 2001
From: Tim te Beek <tim@moderne.io>
Date: Sat, 24 Oct 2026 14:48:21 +0200
Subject: [PATCH] Only convert Java sources in `UseAssertSame`

In Kotlin (and Groovy) `==` calls `equals`, so turning `assertTrue(listOf(1) == listOf(1))` into `assertSame(listOf(1), listOf(1))` changed a passing equality check into a failing identity check. Kotlin tests reach this recipe through `JupiterBestPractices`, so restrict it to Java compilation units with a `JavaFileChecker` precondition.
---
 .../java/testing/junit5/UseAssertSame.java    | 10 +++++---
 .../testing/junit5/UseAssertSameTest.java     | 24 +++++++++++++++++++
 2 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/src/main/java/org/openrewrite/java/testing/junit5/UseAssertSame.java b/src/main/java/org/openrewrite/java/testing/junit5/UseAssertSame.java
index 9eb95e482..7f051d7b9 100644
--- a/src/main/java/org/openrewrite/java/testing/junit5/UseAssertSame.java
+++ b/src/main/java/org/openrewrite/java/testing/junit5/UseAssertSame.java
@@ -26,6 +26,7 @@
 import org.openrewrite.java.tree.Expression;
 import org.openrewrite.java.tree.J;
 import org.openrewrite.java.tree.JavaType;
+import org.openrewrite.staticanalysis.java.JavaFileChecker;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -106,10 +107,13 @@ private JavaType.Method assertSameMethodType(J.MethodInvocation mi, String newMe
                 return assertTrue.withName(newMethodName);
             }
         };
+        // Kotlin and Groovy `==` calls `equals`, so only Java's `==` means `assertSame`
         return Preconditions.check(
-                Preconditions.or(
-                        new UsesMethod<>(ASSERT_TRUE_MATCHER),
-                        new UsesMethod<>(ASSERT_FALSE_MATCHER)),
+                Preconditions.and(
+                        new JavaFileChecker<>(),
+                        Preconditions.or(
+                                new UsesMethod<>(ASSERT_TRUE_MATCHER),
+                                new UsesMethod<>(ASSERT_FALSE_MATCHER))),
                 visitor);
     }
 
diff --git a/src/test/java/org/openrewrite/java/testing/junit5/UseAssertSameTest.java b/src/test/java/org/openrewrite/java/testing/junit5/UseAssertSameTest.java
index fb97e918c..50431fd8d 100644
--- a/src/test/java/org/openrewrite/java/testing/junit5/UseAssertSameTest.java
+++ b/src/test/java/org/openrewrite/java/testing/junit5/UseAssertSameTest.java
@@ -19,10 +19,12 @@
 import org.openrewrite.DocumentExample;
 import org.openrewrite.InMemoryExecutionContext;
 import org.openrewrite.java.JavaParser;
+import org.openrewrite.kotlin.KotlinParser;
 import org.openrewrite.test.RecipeSpec;
 import org.openrewrite.test.RewriteTest;
 
 import static org.openrewrite.java.Assertions.java;
+import static org.openrewrite.kotlin.Assertions.kotlin;
 
 class UseAssertSameTest implements RewriteTest {
     @Override
@@ -256,6 +258,28 @@ public void test(Object obj) {
         );
     }
 
+    @Test
+    void kotlinEqualityIsNotIdentity() {
+        rewriteRun(
+          spec -> spec.parser(KotlinParser.builder()
+            .classpathFromResources(new InMemoryExecutionContext(), "junit-jupiter-api-5")),
+          //language=kotlin
+          kotlin(
+            """
+              import org.junit.jupiter.api.Assertions.assertTrue
+              import org.junit.jupiter.api.Test
+
+              class MyTest {
+                  @Test
+                  fun test() {
+                      assertTrue(listOf(1) == listOf(1))
+                  }
+              }
+              """
+          )
+        );
+    }
+
     @Test
     void onlyConvertsReferenceComparisons() {
         // Wrappers are reference types so == is reference equality (assertSame).