Convert legacy 'native code' to JS-forms in dart:html

lib/html/scripts/systemhtml.py

 #!/usr/bin/python
 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 """This module provides shared functionality for the system to generate
 Dart:html APIs from the IDL database."""
 
 import emitter
 import os
@@ skipping 627 matching lines @@
   def FinishInterface(self):
     pass
 
   def EmitFactoryProvider(self, constructor_info, factory_provider, emitter):
     template_file = ('factoryprovider_%s.darttemplate' %
                      self._html_interface_name)
     template = self._template_loader.TryLoad(template_file)
     if not template:
       template = self._template_loader.Load('factoryprovider.darttemplate')
 
+    arguments = constructor_info.ParametersAsArgumentList()
+    comma = ',' if arguments else ''
     emitter.Emit(
         template,
         FACTORYPROVIDER=factory_provider,
         CONSTRUCTOR=self._html_interface_name,
         PARAMETERS=constructor_info.ParametersImplementationDeclaration(self._DartType),
         NAMED_CONSTRUCTOR=constructor_info.name or self._html_interface_name,
-        ARGUMENTS=constructor_info.ParametersAsArgumentList())
+        ARGUMENTS=arguments,
+        PRE_ARGUMENTS_COMMA=comma,
+        ARGUMENTS_PATTERN=','.join(['#'] * len(constructor_info.param_infos)))
 
   def SecondaryContext(self, interface):
     if interface is not self._current_secondary_parent:
       self._current_secondary_parent = interface
       self._members_emitter.Emit('\n  // From $WHERE\n', WHERE=interface.id)
 
   def AddIndexer(self, element_type):
     """Adds all the methods required to complete implementation of List."""
     # We would like to simply inherit the implementation of everything except
     # length, [], and maybe []=.  It is possible to extend from a base
     # array implementation class only when there is no other implementation
     # inheritance.  There might be no implementation inheritance other than
     # DOMBaseWrapper for many classes, but there might be some where the
     # array-ness is introduced by a non-root interface:
     #
     #   interface Y extends X, List<T> ...
     #
     # In the non-root case we have to choose between:
     #
     #   class YImpl extends XImpl { add List<T> methods; }
     #
     # and
     #
     #   class YImpl extends ListBase<T> { copies of transitive XImpl methods; }
     #
     self._members_emitter.Emit(
         '\n'
-        '  $TYPE operator[](int index) native "return this[index];";\n',
+        '  $TYPE operator[](int index) => JS("$TYPE", "#[#]", this, index);\n',
         TYPE=self._NarrowOutputType(element_type))
 
     if 'CustomIndexedSetter' in self._interface.ext_attrs:
       self._members_emitter.Emit(
           '\n'
-          '  void operator[]=(int index, $TYPE value) native "this[index] = value";\n',
+          '  void operator[]=(int index, $TYPE value) =>'
+          ' JS("void", "#[#] = #", this, index, value);\n',
           TYPE=self._NarrowInputType(element_type))
     else:
       # The HTML library implementation of NodeList has a custom indexed setter
       # implementation that uses the parent node the NodeList is associated
       # with if one is available.
       if self._interface.id != 'NodeList':
         self._members_emitter.Emit(
             '\n'
             '  void operator[]=(int index, $TYPE value) {\n'
             '    throw new UnsupportedOperationException("Cannot assign element of immutable List.");\n'
@@ skipping 44 matching lines @@
     # conversion code.
     if (self._OutputConversion(attribute.type.id, attribute.id) or
         self._InputConversion(attribute.type.id, attribute.id)):
       self._AddAttributeUsingProperties(attribute, html_name, read_only)
       return
 
     output_type = self._NarrowOutputType(attribute.type.id)
     input_type = self._NarrowInputType(attribute.type.id)
     if not read_only:
       self._members_emitter.Emit(
-          '\n  $TYPE $NAME;\n',
+          '\n  $TYPE $NAME;'
+          '\n',
           NAME=DartDomNameOfAttribute(attribute),
           TYPE=output_type)
     else:
       self._members_emitter.Emit(
-          '\n  final $TYPE $NAME;\n',
+          '\n  final $TYPE $NAME;'
+          '\n',
           NAME=DartDomNameOfAttribute(attribute),
           TYPE=output_type)
 
   def _AddAttributeUsingProperties(self, attribute, html_name, read_only):
     self._AddRenamingGetter(attribute, html_name)
     if not read_only:
       self._AddRenamingSetter(attribute, html_name)
 
   def _AddRenamingGetter(self, attr, html_name):
     conversion = self._OutputConversion(attr.type.id, attr.id)
     if conversion:
       return self._AddConvertingGetter(attr, html_name, conversion)
     return_type = self._NarrowOutputType(attr.type.id)
     self._members_emitter.Emit(
-        '\n  $TYPE get $HTML_NAME() native "return this.$NAME;";\n',
+        # TODO(sra): Use metadata to provide native name.
+        '\n  $TYPE get $HTML_NAME() => JS("$TYPE", "#.$NAME", this);'
+        '\n',
         HTML_NAME=html_name,
         NAME=attr.id,
         TYPE=return_type)
 
   def _AddRenamingSetter(self, attr, html_name):
     conversion = self._InputConversion(attr.type.id, attr.id)
     if conversion:
       return self._AddConvertingSetter(attr, html_name, conversion)
     self._members_emitter.Emit(
-        '\n  void set $HTML_NAME($TYPE value)'
-        ' native "this.$NAME = value;";\n',
+        # TODO(sra): Use metadata to provide native name.
+        '\n  void set $HTML_NAME($TYPE value) {'
+        '\n    JS("void", "#.$NAME = #", this, value);'
+        '\n  }'
+        '\n',
         HTML_NAME=html_name,
         NAME=attr.id,
         TYPE=self._NarrowInputType(attr.type.id))
 
   def _AddConvertingGetter(self, attr, html_name, conversion):
     self._members_emitter.Emit(
+        # TODO(sra): Use metadata to provide native name.
         '\n  $RETURN_TYPE get $HTML_NAME => $CONVERT(this._$(HTML_NAME));'
-        '\n  $NATIVE_TYPE get _$HTML_NAME() native "return this.$NAME;";'
+        '\n  $NATIVE_TYPE get _$HTML_NAME() =>'
+        ' JS("$NATIVE_TYPE", "#.$NAME", this);'
         '\n',
         CONVERT=conversion.function_name,
         HTML_NAME=html_name,
         NAME=attr.id,
         RETURN_TYPE=conversion.output_type,
         NATIVE_TYPE=conversion.input_type)
 
   def _AddConvertingSetter(self, attr, html_name, conversion):
     self._members_emitter.Emit(
+        # TODO(sra): Use metadata to provide native name.
         '\n  void set $HTML_NAME($INPUT_TYPE value) {'
-        ' this._$HTML_NAME = $CONVERT(value); }'
-        '\n  void set _$HTML_NAME(/*$NATIVE_TYPE*/ value)'
-        ' native "this.$NAME = value;";'
+        '\n    this._$HTML_NAME = $CONVERT(value);'
+        '\n  }'
+        '\n  void set _$HTML_NAME(/*$NATIVE_TYPE*/ value) {'
+        '\n    JS("void", "#.$NAME = #", this, value);'
+        '\n  }'
         '\n',
         CONVERT=conversion.function_name,
         HTML_NAME=html_name,
         NAME=attr.id,
         INPUT_TYPE=conversion.input_type,
         NATIVE_TYPE=conversion.output_type)
 
   def AmendIndexer(self, element_type):
     pass
 
@@ skipping 291 matching lines @@
 
     library_emitter = self._multiemitter.FileEmitter(library_file_path)
     library_file_dir = os.path.dirname(library_file_path)
     auxiliary_dir = os.path.relpath(auxiliary_dir, library_file_dir)
     imports_emitter = library_emitter.Emit(
         self._template, AUXILIARY_DIR=massage_path(auxiliary_dir))
     for path in sorted(self._path_to_emitter.keys()):
       relpath = os.path.relpath(path, library_file_dir)
       imports_emitter.Emit(
           "#source('$PATH');\n", PATH=massage_path(relpath))