[Extension API Extern Generation] Fix a few bugs in extern generation

tools/json_schema_compiler/js_externs_generator.py

Index: tools/json_schema_compiler/js_externs_generator.py
diff --git a/tools/json_schema_compiler/js_externs_generator.py b/tools/json_schema_compiler/js_externs_generator.py
index 34552a7a888a10fa39c2fb49665c751cb56766ea..99a37a72739f84c2f8588baf587468712a47b3e9 100644
--- a/tools/json_schema_compiler/js_externs_generator.py
+++ b/tools/json_schema_compiler/js_externs_generator.py
@@ -126,7 +126,7 @@ class _Generator(object):
     """Given an OrderedDict of properties, returns a Code containing the
        description of an object.
     """
-    if not properties: return ''
+    if not properties: return Code()
 
     c = Code()
     c.Sblock('{')
@@ -216,7 +216,10 @@ class _Generator(object):
     if js_type.property_type in (PropertyType.INTEGER, PropertyType.DOUBLE):
       c.Append('number')
     elif js_type.property_type is PropertyType.OBJECT:
-      c = self._GenerateObjectDefinition(js_type.properties)
+      if js_type.properties:
+        c = self._GenerateObjectDefinition(js_type.properties)

[Dan Beam, 2015/04/07 01:54:46]

this is OK i guess but it might be mildly better if we just returned the result
right away from each elif, IMO

[Devlin, 2015/04/07 16:13:27]

Yeah, I guess "return Code().Append('foo')" isn't much worse than
"c.Append('foo')", and it makes it more clear in the cases we just return the
result of another method (like here).  Done.

+      else:
+        c.Append('Object')
     elif js_type.property_type is PropertyType.ARRAY:
       (c.Append('!Array<').
            Concat(self._TypeToJsType(js_type.item_type), new_line=False).