Added tests to previously broken functionality and added null checks.

tools/dom/scripts/htmldartgenerator.py

Index: tools/dom/scripts/htmldartgenerator.py
diff --git a/tools/dom/scripts/htmldartgenerator.py b/tools/dom/scripts/htmldartgenerator.py
index 0dc105415817ab79c08e15ece11bbb821d4f9215..87fed8bd9b20dc2f4bb7662c694534fc26bf751d 100644
--- a/tools/dom/scripts/htmldartgenerator.py
+++ b/tools/dom/scripts/htmldartgenerator.py
@@ -240,11 +240,19 @@ class HtmlDartGenerator(object):
         argument = signatures[signature_index][i]
         parameter_name = parameter_names[i]
         test_type = self._DartType(argument.type.id)
+
         if test_type in ['dynamic', 'Object']:
           checks.append('?%s' % parameter_name)
         elif not can_omit_type_check(test_type, i):
           checks.append('(%s is %s || %s == null)' % (
               parameter_name, test_type, parameter_name))
+
+        if can_omit_type_check(test_type, i):

[Anton Muhin, 2013/05/14 06:17:34]

why if, looks like it should be rather else:, see elif at line 246 in patched
version.

+          for signature in signatures:
+            if argument not in signature:

[Anton Muhin, 2013/05/14 06:17:34]

this check looks incorrect: you most probably want to check that given argument
is not present at the given position.

Overall, why this check wasn't needed before and is needed now?

[Andrei Mouravski, 2013/05/21 09:38:49]

Done.

This check wasn't here before because... nobody thought to check this case?
On 2013/05/14 06:17:34, Anton Muhin wrote:

+              checks.append('%s != null' % parameter_name)
+              break
+
       # There can be multiple presence checks.  We need them all since a later
       # optional argument could have been passed by name, leaving 'holes'.
       checks.extend(['!?%s' % name for name in parameter_names[argument_count:]])