Allow J.Empty type parameters in SemanticallyEqual (openrewrite#4266)

* Allow J.Empty type parameters in SemanticallyEqual * Expand tests for generics just to show type is checked
BoykoAlex · Jun 17, 2024 · a49c4d0 · a49c4d0
1 parent 0e35478
commit a49c4d0
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diff --git a/rewrite-java-test/src/test/java/org/openrewrite/java/search/SemanticallyEqualTest.java b/rewrite-java-test/src/test/java/org/openrewrite/java/search/SemanticallyEqualTest.java
@@ -17,6 +17,7 @@
 
 import org.intellij.lang.annotations.Language;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.Nested;
 import org.junitpioneer.jupiter.ExpectedToFail;
 import org.junitpioneer.jupiter.cartesian.CartesianTest;
 import org.openrewrite.java.JavaIsoVisitor;
@@ -298,6 +299,61 @@ class T {
         );
     }
 
+    @Nested
+    class Generics {
+        @Test
+        void firstEmpty() {
+            assertExpressionsEqual(
+              """
+                import java.util.List;
+                class T {
+                    List<String> a = new java.util.ArrayList<String>();
+                    List<String> b = new java.util.ArrayList<>();
+                }
+                """
+            );
+        }
+
+        @Test
+        void secondEmpty() {
+            assertExpressionsEqual(
+              """
+                import java.util.List;
+                class T {
+                    List<String> a = new java.util.ArrayList<>();
+                    List<String> b = new java.util.ArrayList<String>();
+                }
+                """
+            );
+        }
+
+        @Test
+        void bothEmpty() {
+            assertExpressionsEqual(
+              """
+                import java.util.List;
+                class T {
+                    List<String> a = new java.util.ArrayList<>();
+                    List<String> b = new java.util.ArrayList<>();
+                }
+                """
+            );
+        }
+
+        @Test
+        void bothEmptyButDifferent() {
+            assertExpressionsNotEqual(
+              """
+                import java.util.List;
+                class T {
+                    List<String> a = new java.util.ArrayList<>();
+                    List<Integer> b = new java.util.ArrayList<>();
+                }
+                """
+            );
+        }
+    }
+
     private void assertEqualToSelf(@Language("java") String a) {
         assertEqual(a, a);
     }

diff --git a/rewrite-java/src/main/java/org/openrewrite/java/search/SemanticallyEqual.java b/rewrite-java/src/main/java/org/openrewrite/java/search/SemanticallyEqual.java
@@ -1088,7 +1088,9 @@ public J.ParameterizedType visitParameterizedType(J.ParameterizedType type, J j)
                     return type;
                 }
 
-                this.visitList(type.getTypeParameters(), compareTo.getTypeParameters());
+                if (!(type.getTypeParameters().get(0) instanceof J.Empty || compareTo.getTypeParameters().get(0) instanceof J.Empty)) {
+                    this.visitList(type.getTypeParameters(), compareTo.getTypeParameters());
+                }
             }
             return type;
         }