Fix bug in calling super with no parens/args

adambeynon · adambeynon · commit ad90bb35d91e · 2013-07-29T22:06:22.000+01:00
We could not find an isolated test case, but know the bug exists (yes,
poor excuse). We know this fails with Struct.new() so we use that as the
test case
diff --git a/lib/opal/parser.rb b/lib/opal/parser.rb
@@ -1235,6 +1235,10 @@ def js_def(recvr, mid, args, stmts, line, end_line, sexp)
           uses_super = @scope.uses_super
 
           code = [fragment("#{arity_code}#@indent", sexp), @scope.to_vars, code]
+
+          if @scope.uses_zuper
+            code.unshift fragment("var $zuper = __slice.call(arguments, 0);", sexp)
+          end
         end
       end
 
@@ -2077,7 +2081,12 @@ def process_super(sexp, level)
     #
     # s(:zsuper)
     def process_zsuper(exp, level)
-      js_super fragment("__slice.call(arguments)", exp), exp
+      if @scope.def?
+        @scope.uses_zuper = true
+        js_super fragment("$zuper", exp), exp
+      else
+        js_super fragment("__slice.call(arguments)", exp), exp
+      end
     end
 
     def js_super args, sexp
diff --git a/lib/opal/target_scope.rb b/lib/opal/target_scope.rb
@@ -33,6 +33,7 @@ class TargetScope
 
     # uses parents super method
     attr_accessor :uses_super
+    attr_accessor :uses_zuper
 
     # @param [Symbol] type the scope type (:class, :module, :iter, :def, :top)
     # @param [Opal::Parser] parser a parser instance used to create this scope
@@ -88,6 +89,10 @@ def iter?
       @type == :iter
     end
 
+    def def?
+      @type == :def
+    end
+
     # Is this a normal def method directly inside a class? This is
     # used for optimizing ivars as we can set them to nil in the
     # class body
diff --git a/spec/opal/language/super_spec.rb b/spec/opal/language/super_spec.rb
@@ -0,0 +1,8 @@
+require 'spec_helper'
+
+# FIXME: we cant make a better test case than this??? For some reason, a single test cannot be deduced
+describe "The 'super' keyword" do
+  it "passes the right arguments when a variable rewrites special `arguments` js object" do
+    Struct.new(:a, :b, :c).new(1, 2, 3).b.should == 2
+  end
+end
