fix: allow of as identifiers in for loops

Author: amaanq

grammar.js

@@ -297,7 +297,11 @@ module.exports = grammar({
     ),
 
     variable_declarator: $ => seq(
-      field('name', choice($.identifier, $._destructuring_pattern)),
+      field('name', choice(
+        $.identifier,
+        alias('of', $.identifier),
+        $._destructuring_pattern,
+      )),
       optional($._initializer),
     ),
 
@@ -358,6 +362,7 @@ module.exports = grammar({
           field('kind', 'var'),
           field('left', choice(
             $.identifier,
+            alias('of', $.identifier),
             $._destructuring_pattern,
           )),
           optional($._initializer),
@@ -366,6 +371,7 @@ module.exports = grammar({
           field('kind', choice('let', 'const')),
           field('left', choice(
             $.identifier,
+            alias('of', $.identifier),
             $._destructuring_pattern,
           )),
           optional($._automatic_semicolon),
@@ -377,6 +383,7 @@ module.exports = grammar({
           )),
           field('left', choice(
             $.identifier,
+            alias('of', $.identifier),
             $._destructuring_pattern,
           )),
           optional($._automatic_semicolon),

test/corpus/statements.txt

@@ -935,6 +935,33 @@ for await (await using resource of resources) {
           (arguments
             (identifier)))))))
 
+============================================
+'of' as identifier in declarations
+============================================
+
+for (let of of []) break;
+for (const of = '';;) break;
+const of = 2;
+
+---
+
+(program
+  (for_in_statement
+    (identifier)
+    (array)
+    (break_statement))
+  (for_statement
+    (lexical_declaration
+      (variable_declarator
+        (identifier)
+        (string)))
+    (empty_statement)
+    (break_statement))
+  (lexical_declaration
+    (variable_declarator
+      (identifier)
+      (number))))
+
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 Comments
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