refactor: Adopt J.Literal.isLiteralValue(expression, null) (#773)

* refactor: Adopt `J.Literal.isLiteralValue(expression, null)`

Use this link to re-run the recipe: https://app.moderne.io/recipes/org.openrewrite.java.recipes.IsLiteralNullRecipe?organizationId=ODQ2MGExMTUtNDg0My00N2EwLTgzMGMtNGE1NGExMTBmZDkw

Co-authored-by: Moderne <[email protected]>

* Adopt `isLiteralValue` with `null` argument

---------

Co-authored-by: Moderne <[email protected]>

Author: timtebeek

src/main/java/org/openrewrite/java/migrate/lang/var/DeclarationCheck.java

@@ -67,7 +67,7 @@ private static boolean isSingleVariableDefinition(J.VariableDeclarations vd) {
         }
 
         initializer = initializer.unwrap();
-        boolean isNullAssigment = initializer instanceof J.Literal && ((J.Literal) initializer).getValue() == null;
+        boolean isNullAssigment = J.Literal.isLiteralValue(initializer, null);
         boolean alreadyUseVar = typeExpression instanceof J.Identifier && "var".equals(((J.Identifier) typeExpression).getSimpleName());
         return !isNullAssigment && !alreadyUseVar;
     }

src/main/java/org/openrewrite/java/migrate/util/MigrateCollectionsSingletonList.java

@@ -49,7 +49,8 @@ public TreeVisitor<?, ExecutionContext> getVisitor() {
             @Override
             public J.MethodInvocation visitMethodInvocation(J.MethodInvocation method, ExecutionContext ctx) {
                 J.MethodInvocation m = super.visitMethodInvocation(method, ctx);
-                if (SINGLETON_LIST.matches(m) && isNotLiteralNull(m)) {
+                if (SINGLETON_LIST.matches(m) &&
+                        !(J.Literal.isLiteralValue(m.getArguments().get(0), null))) {
                     maybeRemoveImport("java.util.Collections");
                     maybeAddImport("java.util.List");
 
@@ -65,11 +66,6 @@ public J.MethodInvocation visitMethodInvocation(J.MethodInvocation method, Execu
                 }
                 return m;
             }
-
-            private boolean isNotLiteralNull(J.MethodInvocation m) {
-                return !(m.getArguments().get(0) instanceof J.Literal &&
-                         ((J.Literal) m.getArguments().get(0)).getValue() == null);
-            }
         });
     }
 }

src/main/java/org/openrewrite/java/migrate/util/MigrateCollectionsSingletonSet.java

@@ -47,7 +47,8 @@ public TreeVisitor<?, ExecutionContext> getVisitor() {
             @Override
             public J visitMethodInvocation(J.MethodInvocation method, ExecutionContext ctx) {
                 J.MethodInvocation m = (J.MethodInvocation) super.visitMethodInvocation(method, ctx);
-                if (SINGLETON_SET.matches(m) && isNotLiteralNull(m)) {
+                if (SINGLETON_SET.matches(m) &&
+                        !(J.Literal.isLiteralValue(m.getArguments().get(0), null))) {
                     maybeRemoveImport("java.util.Collections");
                     maybeAddImport("java.util.Set");
                     return JavaTemplate.builder("Set.of(#{any()})")
@@ -58,11 +59,6 @@ public J visitMethodInvocation(J.MethodInvocation method, ExecutionContext ctx)
                 }
                 return m;
             }
-
-            private boolean isNotLiteralNull(J.MethodInvocation m) {
-                return !(m.getArguments().get(0) instanceof J.Literal &&
-                         ((J.Literal) m.getArguments().get(0)).getValue() == null);
-            }
         });
     }
 }