Only filter snippets by user-facing languages, #19954

src/vs/workbench/parts/snippets/common/snippetCompletion.ts

@@ -92,6 +92,14 @@ class InsertSnippetAction extends EditorAction {
 				languageId = modeService.getLanguageIdentifier(langId).id;
 			} else {
 				languageId = editor.getModel().getLanguageIdAtPosition(lineNumber, column);
+
+				// validate the `languageId` to ensure this is a user
+				// facing language with a name and the chance to have
+				// snippets, else fall back to the outer language
+				const {language} = modeService.getLanguageIdentifier(languageId);
+				if (!modeService.getLanguageName(language)) {
+					languageId = editor.getModel().getLanguageIdentifier().id;
+				}
 			}
 
 			if (name) {