Skip primitive comparisons in UseAssertSame (#992)

Converting `assertTrue(a == b)` to `assertSame(a, b)` changes value
equality into reference equality on the boxed types, which fails for
mixed primitive types like `123L == 123`.

Author: timtebeek

src/main/java/org/openrewrite/java/testing/junit5/UseAssertSame.java

@@ -67,6 +67,11 @@ public J.MethodInvocation visitMethodInvocation(J.MethodInvocation methodInvocat
                     binary.getRight().getType() == JavaType.Primitive.Null) {
                     return mi;
                 }
+                // Skip primitive comparisons — `==` is value equality, not reference equality
+                if (binary.getLeft().getType() instanceof JavaType.Primitive ||
+                    binary.getRight().getType() instanceof JavaType.Primitive) {
+                    return mi;
+                }
                 List<Expression> newArguments = new ArrayList<>();
                 newArguments.add(binary.getLeft());
                 newArguments.add(binary.getRight());

src/test/java/org/openrewrite/java/testing/junit5/UseAssertSameTest.java

@@ -212,6 +212,28 @@ public void test(Object obj) {
         );
     }
 
+    @Test
+    void primitiveComparisonShouldNotConvert() {
+        //language=java
+        rewriteRun(
+          java(
+            """
+              import org.junit.jupiter.api.Test;
+
+              import static org.junit.jupiter.api.Assertions.assertTrue;
+
+              class MyTest {
+
+                  @Test
+                  public void test() {
+                      assertTrue(123L == 123);
+                  }
+              }
+              """
+          )
+        );
+    }
+
     @Test
     void assertFalseNullShouldNotConvert() {
         //language=java