fix(graphql-language-service): return null instead of empty contents

Author: joshbode

packages/graphql-language-service-server/src/MessageProcessor.ts

@@ -658,7 +658,7 @@ export class MessageProcessor {
     params: TextDocumentPositionParams,
   ): Promise<Hover> {
     if (!this._isInitialized) {
-      return { contents: [] };
+      return null;
     }
 
     this.validateDocumentAndPosition(params);
@@ -667,7 +667,7 @@ export class MessageProcessor {
 
     const cachedDocument = this._getCachedDocument(textDocument.uri);
     if (!cachedDocument) {
-      return { contents: [] };
+      return null;
     }
 
     const found = cachedDocument.contents.find(content => {
@@ -679,7 +679,7 @@ export class MessageProcessor {
 
     // If there is no GraphQL query in this file, return an empty result.
     if (!found) {
-      return { contents: [] };
+      return null;
     }
 
     const { query, range } = found;

packages/graphql-language-service-server/src/__tests__/MessageProcessor.test.ts

@@ -553,7 +553,7 @@ describe('MessageProcessor', () => {
     messageProcessor._getCachedDocument = (_uri: string) => null;
 
     const result = await messageProcessor.handleHoverRequest(test);
-    expect(result).toEqual({ contents: [] });
+    expect(result).toBeNull();
   });
   it('handles provided config', async () => {
     const msgProcessor = new MessageProcessor({