100% coverage for namespaces.py

Also fixes #3

Install zope.pagetemplate for tests and ensure that we use the correct
namespaces.

CHANGES.rst

@@ -7,6 +7,10 @@
 
 - Added support for Python 3.6.
 - Dropped support for Python 3.3.
+- Use the adapter namespace from ``zope.pagetemplate`` if it's
+  available, instead of the backwards compatibility shim in
+  ``zope.app.pagetemplate``. See `issue 3
+  <https://github.com/zopefoundation/z3c.pt/issues/3>`_.
 
 
 3.0 (2016-09-02)

setup.py

@@ -37,6 +37,7 @@ def alltests():
     return unittest.TestSuite(suites)
 
 TESTS_REQUIRE = [
+    'zope.pagetemplate',
     'zope.testing',
     'zope.testrunner',
 ]

src/z3c/pt/README.rst

@@ -390,7 +390,7 @@ Adapters build upon).
   ...     def parent(self):
   ...         return self.context.parent
 
-  >>> function_namespaces.registerFunctionNamespace('ns1', ns1)
+  >>> function_namespaces.namespaces['ns1'] = ns1
 
   >>> class ns2(object):
   ...     def __init__(self, context):

src/z3c/pt/namespaces.py

@@ -93,15 +93,21 @@ def lower(self):
 
 
     def getFunctionNamespace(self, namespacename):
-        """ Returns the function namespace """
+        """
+        Returns the function namespace, if registered.
+
+        Unlike ``__getitem__``, this method will immediately raise a
+        KeyError if no such function is registered.
+        """
         return self.namespaces[namespacename]
 
+function_namespaces = AdapterNamespaces()
+
 try:
-    # If zope.app.pagetemplates is available, use the adapter
-    # registered with the main zope.app.pagetemplates engine so that
+    # If zope.pagetemplate is available, use the adapter
+    # registered with the main zope.pagetemplate engine so that
     # we don't need to re-register them.
-    from zope.app.pagetemplates.engine import Engine
+    from zope.pagetemplate.engine import Engine
     function_namespaces = Engine.namespaces
-except (ImportError, AttributeError):
-    function_namespaces = AdapterNamespaces()
-
+except (ImportError, AttributeError): # pragma: no cover
+    pass

src/z3c/pt/tests/test_namespaces.py

@@ -0,0 +1,34 @@
+# -*- coding: utf-8 -*-
+"""
+Tests for namespaces.py.
+
+"""
+
+import unittest
+
+from z3c.pt import namespaces
+
+class TestAdapterNamespaces(unittest.TestCase):
+
+    def test_registered_name(self):
+        nss = namespaces.AdapterNamespaces()
+        func = lambda ctx: ctx
+        nss.registerFunctionNamespace('ns', func)
+        self.assertIs(func, nss['ns'])
+        self.assertIs(func, nss.getFunctionNamespace('ns'))
+
+    def test_unregistered_name(self):
+        nss = namespaces.AdapterNamespaces()
+        with self.assertRaises(KeyError):
+            nss.getFunctionNamespace('ns')
+
+        # but __getitem__ makes one up
+        self.assertIsNotNone(nss['ns'])
+
+    def test_using_pagetemplate_version(self):
+        from zope.pagetemplate import engine
+
+        self.assertFalse(isinstance(namespaces.function_namespaces,
+                                    namespaces.AdapterNamespaces))
+        self.assertIsInstance(namespaces.function_namespaces,
+                              engine.AdapterNamespaces)