getgroup can also create groups now

--HG--
branch : trunk

py/test/parseopt.py

@@ -38,11 +38,11 @@ class Parser:
         self._groups.append(group)
         return group 
 
-    def getgroup(self, name):
+    def getgroup(self, name, description=""):
         for group in self._groups:
             if group.name == name:
                 return group
-        raise ValueError("group %r not found" %(name,))
+        return self.addgroup(name, description)
 
     def addoption(self, *opts, **attrs):
         """ add an optparse-style option. """

py/test/testing/test_parseopt.py

@@ -18,7 +18,15 @@ class TestParser:
         py.test.raises(ValueError, parser.addgroup, "hello")
         group2 = parser.getgroup("hello")
         assert group2 is group
-        py.test.raises(ValueError, parser.getgroup, 'something')
+
+    def test_getgroup_addsgroup(self):
+        parser = parseopt.Parser()
+        group = parser.getgroup("hello", description="desc")
+        assert group.name == "hello"
+        assert group.description == "desc"
+        group2 = parser.getgroup("hello")
+        assert group2 is group
+
 
     def test_group_addoption(self):
         group = parseopt.OptionGroup("hello")