add support for trailing comma in function arguments

mooz · Sep 30, 2017 · daed014 · daed014
1 parent df51992
commit daed014
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Showing 3 changed files with 11 additions and 1 deletion.
diff --git a/NEWS.md b/NEWS.md
@@ -1,5 +1,9 @@
 # History of user-visible changes
 
+## Next
+
+* Support for trailing comma in function arguments
+
 ## 2017-07-21
 
 * Support for async arrow function without parentheses.

diff --git a/js2-mode.el b/js2-mode.el
@@ -10238,7 +10238,9 @@ Returns the list in reverse order.  Consumes the right-paren token."
                    (js2-unget-token)
                    (push (js2-parse-assign-expr) result)))
                while
-               (js2-match-token js2-COMMA))
+               (and (js2-match-token js2-COMMA)
+                    (or (< js2-language-version 200)
+                        (not (= js2-RP (js2-peek-token))))))
       (js2-must-match js2-RP "msg.no.paren.arg")
       result)))
 

diff --git a/tests/parser.el b/tests/parser.el
@@ -106,6 +106,10 @@ the test."
 (js2-deftest-parse function-statement
   "function foo() {\n}")
 
+(js2-deftest-parse trailing-comma-in-function-arguments
+   "f(a, b,);"
+   :reference "f(a, b);")
+
 (js2-deftest-parse function-statement-inside-block
   "if (true) {\n  function foo() {\n  }\n}")