branch: externals/js2-mode
commit 5e9515dff26ed2fa382c97b0b67cdd370f7859f4
Author: Dmitry Gutov <dgu...@yandex.ru>
Commit: Dmitry Gutov <dgu...@yandex.ru>
Support trailing comma in arrow function params
Fixes #480
---
js2-mode.el | 23 ++++++++++++++---------
tests/parser.el | 4 ++++
2 files changed, 18 insertions(+), 9 deletions(-)
diff --git a/js2-mode.el b/js2-mode.el
index 685cdf9..8327ca3 100644
--- a/js2-mode.el
+++ b/js2-mode.el
@@ -9892,15 +9892,20 @@ If NODE is non-nil, it is the AST node associated with
the symbol."
(while (and (not oneshot)
(js2-match-token js2-COMMA))
(setq op-pos (- (js2-current-token-beg) pos)) ; relative
- (setq right (js2-parse-assign-expr)
- left pn
- pn (make-js2-infix-node :type js2-COMMA
- :pos pos
- :len (- js2-ts-cursor pos)
- :op-pos op-pos
- :left left
- :right right))
- (js2-node-add-children pn left right))
+ (if (eq (js2-peek-token) js2-RP)
+ ;; Stop the parser from scanning too far: it's actually
+ ;; valid syntax in arrow fun arguments, and we don't want
+ ;; the RP token to get consumed.
+ (js2-report-error "msg.syntax")
+ (setq right (js2-parse-assign-expr)
+ left pn
+ pn (make-js2-infix-node :type js2-COMMA
+ :pos pos
+ :len (- js2-ts-cursor pos)
+ :op-pos op-pos
+ :left left
+ :right right))
+ (js2-node-add-children pn left right)))
pn))
(defun js2-parse-assign-expr ()
diff --git a/tests/parser.el b/tests/parser.el
index 23c6ebe..78115f3 100644
--- a/tests/parser.el
+++ b/tests/parser.el
@@ -449,6 +449,10 @@ the test."
(js2-deftest-parse arrow-function-recovers-from-error
"[(,foo) => 1];" :syntax-error "," :errors-count 6)
+(js2-deftest-parse arrow-function-with-trailing-comma-in-arguments
+ "(a, b = 1,) => { c;\n};"
+ :reference "(a, b = 1) => { c;\n};")
+
;;; Automatic semicolon insertion
(js2-deftest-parse no-auto-semi-insertion-after-if
