Fix XML handling of member links (bug 1156594)

This is a was revealed as a blocker for the default_project_id scoping
tests.

Also improves test coverage of XML de/serialization invertibility. The
tests were previously sensitive to things like attribute ordering which
are not relevant to test results. The fix is to compare canonically
serialized XML instead of whatever lxml spews out.

Change-Id: I003583038421d35aadbc781144d4cafb09392db5

1 files changed, 52 insertions, 24 deletions

diff --git a/tests/test_serializer.py b/tests/test_serializer.py
index 8ea49015..b440c815 100644
--- a/tests/test_serializer.py
+++ b/tests/test_serializer.py
@@ -15,44 +15,52 @@
 # under the License.
 
 import copy
-import re
+import StringIO
+
+from lxml import etree
 
 from keystone.common import serializer
 from keystone import test
 
 
 class XmlSerializerTestCase(test.TestCase):
-    def assertEqualIgnoreWhitespace(self, a, b):
-        """Splits two strings into lists and compares them.
+    def assertEqualXML(self, a, b):
+        """Parses two XML documents from strings and compares the results.
 
         This provides easy-to-read failures from nose.
 
         """
-        try:
-            self.assertEqual(a, b)
-        except AssertionError:
-            a = re.sub('[ \n]+', ' ', a).strip().split()
-            b = re.sub('[ \n]+', ' ', b).strip().split()
-            self.assertEqual(a, b)
+        parser = etree.XMLParser(remove_blank_text=True)
+
+        def canonical_xml(s):
+            s = s.strip()
+
+            fp = StringIO.StringIO()
+            dom = etree.fromstring(s, parser)
+            dom.getroottree().write_c14n(fp)
+            s = fp.getvalue()
+
+            dom = etree.fromstring(s, parser)
+            return etree.tostring(dom, pretty_print=True)
+
+        a = canonical_xml(a)
+        b = canonical_xml(b)
+        self.assertEqual(a.split('\n'), b.split('\n'))
 
     def assertSerializeDeserialize(self, d, xml, xmlns=None):
-        self.assertEqualIgnoreWhitespace(serializer.to_xml(d, xmlns), xml)
+        self.assertEqualXML(
+            serializer.to_xml(copy.deepcopy(d), xmlns),
+            xml)
         self.assertEqual(serializer.from_xml(xml), d)
 
-        # operations should be invertable
+        # operations should be invertible
         self.assertEqual(
-            serializer.from_xml(serializer.to_xml(d, xmlns)),
+            serializer.from_xml(serializer.to_xml(copy.deepcopy(d), xmlns)),
             d)
-        self.assertEqualIgnoreWhitespace(
+        self.assertEqualXML(
             serializer.to_xml(serializer.from_xml(xml), xmlns),
             xml)
 
-    def test_none(self):
-        d = None
-        xml = None
-
-        self.assertSerializeDeserialize(d, xml)
-
     def test_auth_request(self):
         d = {
             "auth": {
@@ -155,7 +163,7 @@ class XmlSerializerTestCase(test.TestCase):
                 <policy id="ab12cd"/>
             </policies>
         """
-        self.assertEqualIgnoreWhitespace(serializer.to_xml(d), xml)
+        self.assertEqualXML(serializer.to_xml(d), xml)
 
     def test_values_list(self):
         d = {
@@ -176,7 +184,7 @@ class XmlSerializerTestCase(test.TestCase):
             </objects>
         """
 
-        self.assertEqualIgnoreWhitespace(serializer.to_xml(d), xml)
+        self.assertEqualXML(serializer.to_xml(d), xml)
 
     def test_collection_list(self):
         d = {
@@ -222,6 +230,26 @@ class XmlSerializerTestCase(test.TestCase):
                 </links>
             </objects>
         """
-        self.assertEqualIgnoreWhitespace(
-            serializer.to_xml(copy.deepcopy(d)), xml)
-        self.assertDictEqual(serializer.from_xml(xml), d)
+        self.assertSerializeDeserialize(d, xml)
+
+    def test_collection_member(self):
+        d = {
+            "object": {
+                "attribute": "value",
+                "links": {
+                    "self": "http://localhost:5000/v3/objects/abc123def",
+                    "anotherobj": "http://localhost:5000/v3/anotherobjs/123"}}}
+
+        xml = """
+            <?xml version="1.0" encoding="UTF-8"?>
+            <object xmlns="http://docs.openstack.org/identity/api/v2.0"
+                attribute="value">
+                    <links>
+                        <link rel="self"
+                            href="http://localhost:5000/v3/objects/abc123def"/>
+                        <link rel="anotherobj"
+                            href="http://localhost:5000/v3/anotherobjs/123"/>
+                    </links>
+            </object>
+        """
+        self.assertSerializeDeserialize(d, xml)