From 87cfd408316d1e6712f167e74dde9832624fb709 Mon Sep 17 00:00:00 2001
From: Dmitry Gutov <dgutov@yandex.ru>
Date: Wed, 5 Nov 2014 11:45:15 +0200
Subject: [PATCH] Support object destructuring inside arrow function args

* js2-mode.el (js2-parse-plain-property): Don't move too far when
there's no colon.
(js2-parse-assign-expr): Restore the previous value of
`js2-parsed-errors' after arrow token is found.

Fixes #167
---
 js2-mode.el     | 40 ++++++++++++++++++++++------------------
 tests/parser.el |  7 +++++--
 2 files changed, 27 insertions(+), 20 deletions(-)

diff --git a/js2-mode.el b/js2-mode.el
index ba0ba4e87..0141eb418 100644
--- a/js2-mode.el
+++ b/js2-mode.el
@@ -8571,13 +8571,14 @@ If NODE is non-nil, it is the AST node associated with the symbol."
   (let ((tt (js2-get-token))
         (pos (js2-current-token-beg))
         pn left right op-pos
-        ts-state recorded-identifiers)
+        ts-state recorded-identifiers parsed-errors)
     (if (= tt js2-YIELD)
         (js2-parse-return-or-yield tt t)
       ;; Save the tokenizer state in case we find an arrow function
       ;; and have to rewind.
       (setq ts-state (make-js2-ts-state)
-            recorded-identifiers js2-recorded-identifiers)
+            recorded-identifiers js2-recorded-identifiers
+            parsed-errors js2-parsed-errors)
       ;; not yield - parse assignment expression
       (setq pn (js2-parse-cond-expr)
             tt (js2-get-token))
@@ -8602,7 +8603,8 @@ If NODE is non-nil, it is the AST node associated with the symbol."
        ((and (= tt js2-ARROW)
              (>= js2-language-version 200))
         (js2-ts-seek ts-state)
-        (setq js2-recorded-identifiers recorded-identifiers)
+        (setq js2-recorded-identifiers recorded-identifiers
+              js2-parsed-errors parsed-errors)
         (setq pn (js2-parse-function 'FUNCTION_ARROW (js2-current-token-beg) nil)))
        (t
         (js2-unget-token)))
@@ -9600,21 +9602,23 @@ When `js2-is-in-destructuring' is t, forms like {a, b, c} will be permitted."
 (defun js2-parse-plain-property (prop)
   "Parse a non-getter/setter property in an object literal.
 PROP is the node representing the property:  a number, name or string."
-  (js2-must-match js2-COLON "msg.no.colon.prop")
-  (let* ((pos (js2-node-pos prop))
-        (colon (- (js2-current-token-beg) pos))
-        (expr (js2-parse-assign-expr))
-        (result (make-js2-object-prop-node
-                 :pos pos
-                 ;; don't include last consumed token in length
-                 :len (- (+ (js2-node-pos expr)
-                            (js2-node-len expr))
-                         pos)
-                 :left prop
-                 :right expr
-                 :op-pos colon)))
-    (js2-node-add-children result prop expr)
-    result))
+  (let ((pos (js2-node-pos prop))
+        colon expr)
+    (if (js2-must-match js2-COLON "msg.no.colon.prop")
+        (setq colon (- (js2-current-token-beg) pos)
+              expr (js2-parse-assign-expr))
+      (setq expr (make-js2-error-node)))
+    (let ((result (make-js2-object-prop-node
+                   :pos pos
+                   ;; don't include last consumed token in length
+                   :len (- (+ (js2-node-pos expr)
+                              (js2-node-len expr))
+                           pos)
+                   :left prop
+                   :right expr
+                   :op-pos colon)))
+      (js2-node-add-children result prop expr)
+      result)))
 
 (defun js2-parse-getter-setter-prop (pos prop get-p)
   "Parse getter or setter property in an object literal.
diff --git a/tests/parser.el b/tests/parser.el
index 1df960366..ffda856c8 100644
--- a/tests/parser.el
+++ b/tests/parser.el
@@ -222,11 +222,14 @@ the test."
 (js2-deftest-parse arrow-function-with-args-and-curlies
   "(a, b = 1, ...c) => {  c;\n};")
 
+(js2-deftest-parse arrow-function-with-destructuring
+  "([{a}, b]) => {  a + b;\n};")
+
 (js2-deftest-parse parenless-arrow-function-prohibits-rest
-  "...b => {b + 1;};" :syntax-error "=>" :errors-count 2)
+  "...b => {b + 1;};" :syntax-error "=>" :errors-count 1)
 
 (js2-deftest-parse parenless-arrow-function-prohibits-destructuring
-  "[a, b] => {a + b;};" :syntax-error "=>" :errors-count 5)
+  "[a, b] => {a + b;};" :syntax-error "=>" :errors-count 4)
 
 ;;; Automatic semicolon insertion
 
-- 
2.39.2