Make comment retrieval pretty

eclipse-langium · Jul 10, 2023 · df3856a · df3856a
1 parent e4a93c8
commit df3856a
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Showing 2 changed files with 7 additions and 3 deletions.
diff --git a/packages/langium/src/documentation/comment-provider.ts b/packages/langium/src/documentation/comment-provider.ts
@@ -5,7 +5,7 @@
  ******************************************************************************/
 
 import type { GrammarConfig } from '../grammar';
-import type { AstNodeWithComment } from '../serializer';
+import { isAstNodeWithComment } from '../serializer';
 import type { LangiumServices } from '../services';
 import type { AstNode } from '../syntax-tree';
 import { findCommentNode } from '../utils/cst-util';
@@ -28,8 +28,8 @@ export class DefaultCommentProvider implements CommentProvider {
         this.grammarConfig = () => services.parser.GrammarConfig;
     }
     getComment(node: AstNode): string | undefined {
-        if('$comment' in node) {
-            return (node as AstNodeWithComment).$comment;
+        if(isAstNodeWithComment(node)) {
+            return node.$comment;
         }
         return findCommentNode(node.$cstNode, this.grammarConfig().multilineCommentRules)?.text;
     }

diff --git a/packages/langium/src/serializer/json-serializer.ts b/packages/langium/src/serializer/json-serializer.ts
@@ -39,6 +39,10 @@ export interface AstNodeWithComment extends AstNode {
     $comment?: string;
 }
 
+export function isAstNodeWithComment(node: AstNode): node is AstNodeWithComment {
+    return typeof (node as AstNodeWithComment).$comment === 'string';
+}
+
 /**
  * A {@DocumentSegment} representing the definition area of an AstNode within the DSL text.
  * Usually contains text region information on all assigned property values of the AstNode,