From dd344ff6d7b079f1ca9fe967cd7e8b6850a4231c Mon Sep 17 00:00:00 2001
From: Stephen Hicks <sdh@google.com>
Date: Mon, 10 Nov 2014 16:14:14 -0800
Subject: [PATCH] Support short-hand object literals {foo, bar} everywhere.
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This is specified in §12.2.5 of the draft spec (http://people.mozilla.org/~jorendorff/es6-draft.html#sec-object-initializer) by the production [PropertyDefinition : IdentifierReference], and discussed e.g. in http://ariya.ofilabs.com/2013/02/es6-and-object-literal-property-value-shorthand.html.
---
 js2-mode.el     | 54 +++++++++++++++++++++++++++++++++++++------------
 tests/parser.el |  5 +++++
 2 files changed, 46 insertions(+), 13 deletions(-)

diff --git a/js2-mode.el b/js2-mode.el
index d6a0d295b..db625ca80 100644
--- a/js2-mode.el
+++ b/js2-mode.el
@@ -3523,10 +3523,20 @@ The `right' field is a `js2-node' representing the initializer value.")
 (put 'cl-struct-js2-object-prop-node 'js2-printer 'js2-print-object-prop-node)
 
 (defun js2-print-object-prop-node (n i)
-  (insert (js2-make-pad i))
-  (js2-print-ast (js2-object-prop-node-left n) 0)
-  (insert ": ")
-  (js2-print-ast (js2-object-prop-node-right n) 0))
+  (let* ((left (js2-object-prop-node-left n))
+         (computed (not (or (js2-string-node-p left)
+                            (js2-number-node-p left)
+                            (js2-name-node-p left)))))
+    (insert (js2-make-pad i))
+    (if computed
+        (insert "["))
+    (js2-print-ast left 0)
+    (if computed
+        (insert "]"))
+    (if (not (js2-node-get-prop n 'SHORTHAND))
+        (progn
+          (insert ": ")
+          (js2-print-ast (js2-object-prop-node-right n) 0)))))
 
 (defstruct (js2-getter-setter-node
             (:include js2-infix-node)
@@ -9602,13 +9612,31 @@ 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."
-  (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
+  (let* ((tt (js2-get-token))
+         (pos (js2-node-pos prop))
+         colon expr result)
+    (cond
+     ;; Abbreviated property, as in {foo, bar}
+     ((and (>= js2-language-version 200)
+           (or (= tt js2-COMMA)
+               (= tt js2-RC)))
+      (js2-unget-token)
+      (setq result (make-js2-object-prop-node
+                    :pos pos
+                    :left prop
+                    :right prop
+                    :op-pos (js2-current-token-len)))
+      (js2-node-add-children result prop)
+      (js2-node-set-prop result 'SHORTHAND t)
+      result)
+     ;; Normal property
+     (t
+      (if (= tt js2-COLON)
+          (setq colon (- (js2-current-token-beg) pos)
+                expr (js2-parse-assign-expr))
+        (js2-report-error "msg.no.colon.prop")
+        (setq expr (make-js2-error-node)))
+      (setq result (make-js2-object-prop-node
                    :pos pos
                    ;; don't include last consumed token in length
                    :len (- (+ (js2-node-pos expr)
@@ -9616,9 +9644,9 @@ PROP is the node representing the property:  a number, name or string."
                            pos)
                    :left prop
                    :right expr
-                   :op-pos colon)))
+                   :op-pos colon))
       (js2-node-add-children result prop expr)
-      result)))
+      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 ffda856c8..1c903be87 100644
--- a/tests/parser.el
+++ b/tests/parser.el
@@ -179,6 +179,11 @@ the test."
 (js2-deftest-parse destruct-in-catch-clause
   "try {\n} catch ({a, b}) {\n  a + b;\n}")
 
+;;; Object literals
+
+(js2-deftest-parse abbreviated-object
+  "var x = {a: 1, b, c: 1, d};")
+
 ;;; Function parameters
 
 (js2-deftest-parse function-with-default-parameters
-- 
2.39.2