more accurate type to avoid type assertion and destructure

Author: Janther

src/slang-nodes/types.d.ts

@@ -460,6 +460,11 @@ export type StrictAstNode =
   | YulPaths
   | YulPath;
 
+export type PrintableCollectionNode = Extract<
+  StrictAstNode,
+  { items: StrictAstNode[] }
+>;
+
 export type CollectionNode = Extract<StrictAstNode, { items: unknown[] }>;
 
 export type BinaryOperation = Extract<

src/slang-printers/print-preserving-empty-lines.ts

@@ -5,20 +5,19 @@ import { locEnd } from '../slang-utils/loc.js';
 import type { AstPath, Doc, ParserOptions } from 'prettier';
 import type {
   AstNode,
-  CollectionNode,
-  StrictAstNode
+  PrintableCollectionNode
 } from '../slang-nodes/types.d.ts';
 import type { PrintFunction } from '../types.d.ts';
 
 const { hardline } = doc.builders;
 
 export function printPreservingEmptyLines(
-  path: AstPath<CollectionNode>,
+  path: AstPath<PrintableCollectionNode>,
   print: PrintFunction,
   options: ParserOptions<AstNode>
 ): Doc {
   return path.map((childPath) => {
-    const node = childPath.node as StrictAstNode;
+    const { node } = childPath;
 
     return [
       // Only attempt to prepend an empty line if `node` is not the first item