Merge pull request #4073 from lydell/issue-3926

Fix #3926: Disallow implicit objects as parameter destructuring

src/grammar.coffee

@@ -168,9 +168,11 @@ grammar =
   # the ordinary **Assign** is that these allow numbers and strings as keys.
   AssignObj: [
     o 'ObjAssignable',                          -> new Value $1
-    o 'ObjAssignable : Expression',             -> new Assign LOC(1)(new Value $1), $3, 'object'
+    o 'ObjAssignable : Expression',             -> new Assign LOC(1)(new Value $1), $3, 'object',
+                                                              operatorToken: LOC(2)(new Literal $2)
     o 'ObjAssignable :
-       INDENT Expression OUTDENT',              -> new Assign LOC(1)(new Value $1), $4, 'object'
+       INDENT Expression OUTDENT',              -> new Assign LOC(1)(new Value $1), $4, 'object',
+                                                              operatorToken: LOC(2)(new Literal $2)
     o 'SimpleObjAssignable = Expression',       -> new Assign LOC(1)(new Value $1), $3, null,
                                                               operatorToken: LOC(2)(new Literal $2)
     o 'SimpleObjAssignable =

src/nodes.coffee

@@ -1482,6 +1482,9 @@ exports.Param = class Param extends Base
   constructor: (@name, @value, @splat) ->
     if (name = @name.unwrapAll().value) in STRICT_PROSCRIBED
       @name.error "parameter name \"#{name}\" is not allowed"
+    if @name instanceof Obj and @name.generated
+      token = @name.objects[0].operatorToken
+      token.error "unexpected #{token.value}"
 
   children: ['name', 'value']
 

test/error_messages.coffee

@@ -808,3 +808,19 @@ test "#4070: lone expansion", ->
     [ ..., ] = a
       ^^^
   '''
+
+test "#3926: implicit object in parameter list", ->
+  assertErrorFormat '''
+    (a: b) ->
+  ''', '''
+    [stdin]:1:3: error: unexpected :
+    (a: b) ->
+      ^
+  '''
+  assertErrorFormat '''
+    (one, two, {three, four: five}, key: value) ->
+  ''', '''
+    [stdin]:1:36: error: unexpected :
+    (one, two, {three, four: five}, key: value) ->
+                                       ^
+  '''

test/strict.coffee

@@ -93,7 +93,6 @@ test "duplicate formal parameters are prohibited", ->
   strict '(_,[_,{__}])->',   'param, [param, {param2}]'
   strict '(_,[__,{_}])->',   'param, [param2, {param}]'
   strict '(__,[_,{_}])->',   'param, [param2, {param2}]'
-  strict '(0:a,1:a)->',      '0:param,1:param'
   strict '({0:a,1:a})->',    '{0:param,1:param}'
   # the following function expressions should **not** throw errors
   strictOk '(_,@_)->'
@@ -115,8 +114,8 @@ test "duplicate formal parameters are prohibited", ->
   strictOk '(@case...,_case)->'
   strictOk '(_case,@case)->'
   strictOk '(_case,@case...)->'
-  strictOk '(a:a)->'
-  strictOk '(a:a,a:b)->'
+  strictOk '({a:a})->'
+  strictOk '({a:a,a:b})->'
 
 test "`delete` operand restrictions", ->
   strict 'a = 1; delete a'