Combine semantically equal catch blocks with same var declarations (#280

)

* Add test for CombineSemanticallyEqualCatchBlocks having equal catch
blocks with variable declaration

* Do not try to compare nullable varargs in catch blocks for
CombineSemanticallyEqualCatchBlocks recipe. Fixes NPE.

* Revert "Do not try to compare nullable varargs in catch blocks for"

This reverts commit a248d1d.

* Fix NPE in CombineSemanticallyEqualCatchBlocks recipe when trying to determine if catch blocks do not contain same comments

---------

Co-authored-by: Tim te Beek <[email protected]>

src/main/java/org/openrewrite/staticanalysis/CombineSemanticallyEqualCatchBlocks.java

@@ -299,7 +299,11 @@ private boolean nullMissMatch(Object obj1, Object obj2) {
             }
 
             private boolean doesNotContainSameComments(Space space1, Space space2) {
-                if (space1.getComments().size() != space2.getComments().size()) {
+                if (space1 == null && space2 == null) {
+                    return false;
+                }
+
+                if (space1 == null || space2 == null || space1.getComments().size() != space2.getComments().size()) {
                     return true;
                 }
 

src/test/java/org/openrewrite/staticanalysis/CombineSemanticallyEqualCatchBlocksTest.java

@@ -448,4 +448,40 @@ void log(String msg) {}
           )
         );
     }
+
+
+    @Test
+    void combineSameCatchBlocksWithVariableDeclaration() {
+        rewriteRun(
+          //language=java
+          java("class A extends RuntimeException {}"),
+          //language=java
+          java("class B extends RuntimeException {}"),
+          //language=java
+          java(
+            """
+              class Test {
+                  void method() {
+                      try {
+                      } catch (A ex) {
+                          String s = "foo";
+                      } catch (B ex) {
+                          String s = "foo";
+                      }
+                  }
+              }
+              """,
+            """
+              class Test {
+                  void method() {
+                      try {
+                      } catch (A | B ex) {
+                          String s = "foo";
+                      }
+                  }
+              }
+              """
+          )
+        );
+    }
 }