Groovy: Fix NPE with generics of an unknown class (#7488)

Author: greg-at-moderne

rewrite-groovy/src/main/java/org/openrewrite/groovy/GroovyParser.java

@@ -133,7 +133,9 @@ public Stream<SourceFile> parseInputs(Iterable<Input> sources, @Nullable Path re
                                 StaticTypeCheckingVisitor staticTypeCheckingVisitor = new StaticTypeCheckingVisitor(unit, aClass);
                                 staticTypeCheckingVisitor.setCompilationUnit(compUnit);
                                 staticTypeCheckingVisitor.visitClass(aClass);
-                            } catch (NoClassDefFoundError ignored) {
+                            } catch (NoClassDefFoundError | NullPointerException ignored) {
+                                // Static type checking is best-effort; skip enrichment when Groovy fails internally
+                                // (e.g., NPE in inferDiamondType when diamond is used with an unresolved imported class).
                             }
                         }
 

rewrite-groovy/src/test/java/org/openrewrite/groovy/tree/VariableDeclarationsTest.java

@@ -111,6 +111,18 @@ void diamondOperator() {
         );
     }
 
+    @Test
+    void diamondOperatorOnUnresolvedImportedType() {
+        rewriteRun(
+          groovy(
+            """
+              import a.b.Foo
+              def x = new Foo<>()
+              """
+          )
+        );
+    }
+
     @Test
     void singleTypeMultipleVariableDeclaration() {
         rewriteRun(