Add a shim to move a comment extra into a body node

make_grammar.js

@@ -25,6 +25,7 @@ module.exports = function make_grammar(dialect) {
       $.template_directive_start,
       $.template_directive_end,
       $.heredoc_identifier,
+      $._shim,
     ],
 
     extras: $ => [
@@ -36,10 +37,13 @@ module.exports = function make_grammar(dialect) {
       // also allow objects to handle .tfvars in json format
       config_file: $ => optional(choice($.body, $.object)),
 
-      body: $ => repeat1(
-        choice(
-          $.attribute,
-          $.block,
+      body: $ => seq(
+        optional($._shim),
+        repeat1(
+          choice(
+            $.attribute,
+            $.block,
+          ),
         ),
       ),
 

src/scanner.cc

@@ -20,6 +20,7 @@ enum TokenType {
   TEMPLATE_DIRECTIVE_START,
   TEMPLATE_DIRECTIVE_END,
   HEREDOC_IDENTIFIER,
+  SHIM,
 };
 
 enum ContextType {
@@ -96,6 +97,11 @@ public:
     if (lexer->lookahead == '\0') {
       return false;
     }
+    if (valid_symbols[SHIM]) {
+      if (lexer->lookahead != '}') {
+        return accept_inplace(lexer, SHIM);
+      }
+    }
     // manage quoted context
     if (valid_symbols[QUOTED_TEMPLATE_START] && !in_quoted_context() &&
         lexer->lookahead == '"') {