Rest of tests ported, just need to hook up doctests now.

--HG--
branch : trunk
diff --git a/jinja2/testsuite/ext.py b/jinja2/testsuite/ext.py
index 57298ac..3bb5276 100644
--- a/jinja2/testsuite/ext.py
+++ b/jinja2/testsuite/ext.py
@@ -13,7 +13,8 @@
 
 from jinja2.testsuite import JinjaTestCase, filesystem_loader
 
-from jinja2 import Environment, nodes
+from jinja2 import Environment, DictLoader, contextfunction, nodes
+from jinja2.exceptions import TemplateAssertionError
 from jinja2.ext import Extension
 from jinja2.lexer import Token, count_newlines
 
@@ -23,6 +24,53 @@
 _gettext_re = re.compile(r'_\((.*?)\)(?s)')
 
 
+templates = {
+    'master.html': '<title>{{ page_title|default(_("missing")) }}</title>'
+                   '{% block body %}{% endblock %}',
+    'child.html': '{% extends "master.html" %}{% block body %}'
+                  '{% trans %}watch out{% endtrans %}{% endblock %}',
+    'plural.html': '{% trans user_count %}One user online{% pluralize %}'
+                   '{{ user_count }} users online{% endtrans %}',
+    'stringformat.html': '{{ _("User: %d")|format(user_count) }}'
+}
+
+
+languages = {
+    'de': {
+        'missing':                      'fehlend',
+        'watch out':                    'pass auf',
+        'One user online':              'Ein Benutzer online',
+        '%(user_count)s users online':  '%(user_count)s Benutzer online',
+        'User: %d':                     'Benutzer: %d'
+    }
+}
+
+
+@contextfunction
+def gettext(context, string):
+    language = context.get('LANGUAGE', 'en')
+    return languages.get(language, {}).get(string, string)
+
+
+@contextfunction
+def ngettext(context, s, p, n):
+    language = context.get('LANGUAGE', 'en')
+    if n != 1:
+        return languages.get(language, {}).get(p, p)
+    return languages.get(language, {}).get(s, s)
+
+
+i18n_env = Environment(
+    loader=DictLoader(templates),
+    extensions=['jinja2.ext.i18n']
+)
+i18n_env.globals.update({
+    '_':            gettext,
+    'gettext':      gettext,
+    'ngettext':     ngettext
+})
+
+
 class TestExtension(Extension):
     tags = set(['test'])
     ext_attr = 42
@@ -150,7 +198,61 @@
         assert out == 'Foo BAR Baz'
 
 
+class InternationalizationTestCase(JinjaTestCase):
+
+    def test_trans(self):
+        tmpl = i18n_env.get_template('child.html')
+        assert tmpl.render(LANGUAGE='de') == '<title>fehlend</title>pass auf'
+
+    def test_trans_plural(self):
+        tmpl = i18n_env.get_template('plural.html')
+        assert tmpl.render(LANGUAGE='de', user_count=1) == 'Ein Benutzer online'
+        assert tmpl.render(LANGUAGE='de', user_count=2) == '2 Benutzer online'
+
+    def test_complex_plural(self):
+        tmpl = i18n_env.from_string('{% trans foo=42, count=2 %}{{ count }} item{% '
+                                    'pluralize count %}{{ count }} items{% endtrans %}')
+        assert tmpl.render() == '2 items'
+        self.assert_raises(TemplateAssertionError, i18n_env.from_string,
+                           '{% trans foo %}...{% pluralize bar %}...{% endtrans %}')
+
+    def test_trans_stringformatting(self):
+        tmpl = i18n_env.get_template('stringformat.html')
+        assert tmpl.render(LANGUAGE='de', user_count=5) == 'Benutzer: 5'
+
+    def test_extract(self):
+        from jinja2.ext import babel_extract
+        from StringIO import StringIO
+        source = StringIO('''
+        {{ gettext('Hello World') }}
+        {% trans %}Hello World{% endtrans %}
+        {% trans %}{{ users }} user{% pluralize %}{{ users }} users{% endtrans %}
+        ''')
+        assert list(babel_extract(source, ('gettext', 'ngettext', '_'), [], {})) == [
+            (2, 'gettext', u'Hello World', []),
+            (3, 'gettext', u'Hello World', []),
+            (4, 'ngettext', (u'%(users)s user', u'%(users)s users', None), [])
+        ]
+
+    def test_comment_extract(self):
+        from jinja2.ext import babel_extract
+        from StringIO import StringIO
+        source = StringIO('''
+        {# trans first #}
+        {{ gettext('Hello World') }}
+        {% trans %}Hello World{% endtrans %}{# trans second #}
+        {#: third #}
+        {% trans %}{{ users }} user{% pluralize %}{{ users }} users{% endtrans %}
+        ''')
+        assert list(babel_extract(source, ('gettext', 'ngettext', '_'), ['trans', ':'], {})) == [
+            (3, 'gettext', u'Hello World', ['first']),
+            (4, 'gettext', u'Hello World', ['second']),
+            (6, 'ngettext', (u'%(users)s user', u'%(users)s users', None), ['third'])
+        ]
+
+
 def suite():
     suite = unittest.TestSuite()
     suite.addTest(unittest.makeSuite(ExtensionsTestCase))
+    suite.addTest(unittest.makeSuite(InternationalizationTestCase))
     return suite