fix: a receiver parameter can be followed by more parameters

Author: amaanq

grammar.js

@@ -1192,8 +1192,13 @@ module.exports = grammar({
 
     formal_parameters: $ => seq(
       '(',
-      optional($.receiver_parameter),
-      commaSep(choice($.formal_parameter, $.spread_parameter)),
+      choice(
+        $.receiver_parameter,
+        seq(
+          optional(seq($.receiver_parameter, ',')),
+          commaSep(choice($.formal_parameter, $.spread_parameter)),
+        ),
+      ),
       ')'
     ),
 

test/corpus/declarations.txt

@@ -664,6 +664,37 @@ public class Inner1<T> {
                     (this)))
                 (constructor_body)))))))))
 
+================================================================================
+Receiver parameter with additional parameters
+================================================================================
+
+public class A {
+  public B(A this) {}
+
+  public C(A this, D that) {}
+}
+
+---
+
+(program
+  (class_declaration
+    (modifiers)
+    (identifier)
+    (class_body
+      (constructor_declaration
+        (modifiers)
+        (identifier)
+        (formal_parameters
+          (receiver_parameter (type_identifier) (this)))
+        (constructor_body))
+      (constructor_declaration
+        (modifiers)
+        (identifier)
+        (formal_parameters
+          (receiver_parameter (type_identifier) (this))
+          (formal_parameter (type_identifier) (identifier)))
+        (constructor_body)))))
+
 ================================================================================
 throws
 ================================================================================