[CS2] Output ES2015 arrow functions, default parameters, rest parameters

src/nodes.coffee

@@ -1608,6 +1608,8 @@ exports.Code = class Code extends Base
   # function body.
   compileNode: (o) ->
     if @bound
+      if @isGenerator
+        @error "bound (fat arrow) functions cannot contain 'yield'"
       @context = o.scope.method.context if o.scope.method?.bound
       @context = 'this' unless @context
 

test/error_messages.coffee

@@ -1142,3 +1142,10 @@ test "imported members cannot be reassigned", ->
     export foo = 'bar'
            ^^^
   '''
+
+test "bound functions cannot be generators", ->
+  assertErrorFormat 'f = => yield this', '''
+    [stdin]:1:5: error: bound (fat arrow) functions cannot contain 'yield'
+    f = => yield this
+        ^^^^^^^^^^^^^
+  '''

test/generators.coffee

@@ -52,24 +52,6 @@ test "yield return can be used anywhere in the function body", ->
   y = x.next 2
   ok y.value is 42 and y.done is true
 
-test "bound generator", ->
-  obj =
-    bound: ->
-      do =>
-        yield this
-    unbound: ->
-      do ->
-        yield this
-    nested: ->
-      do =>
-        yield do =>
-          yield do =>
-            yield this
-
-  eq obj, obj.bound().next().value
-  ok obj isnt obj.unbound().next().value
-  eq obj, obj.nested().next().value.next().value.next().value
-
 test "`yield from` support", ->
   x = do ->
     yield from do ->