diff -r 1bb43e31032d -r a14b6562082b test/unittest_utils.py
--- a/test/unittest_utils.py	Tue Feb 14 15:14:22 2012 +0100
+++ b/test/unittest_utils.py	Tue Jul 10 15:07:23 2012 +0200
@@ -26,7 +26,7 @@
 
 from cubicweb.devtools.testlib import CubicWebTC
 from cubicweb.utils import (make_uid, UStringIO, SizeConstrainedList,
-                            RepeatList, HTMLHead)
+                            RepeatList, HTMLHead, QueryCache)
 from cubicweb.entity import Entity
 
 try:
@@ -50,6 +50,55 @@
                           'some numeric character, got %s' % uid)
             d.add(uid)
 
+class TestQueryCache(TestCase):
+    def test_querycache(self):
+        c = QueryCache(ceiling=20)
+        # write only
+        for x in xrange(10):
+            c[x] = x
+        self.assertEqual(c._usage_report(),
+                         {'transientcount': 0,
+                          'itemcount': 10,
+                          'permanentcount': 0})
+        c = QueryCache(ceiling=10)
+        # we should also get a warning
+        for x in xrange(20):
+            c[x] = x
+        self.assertEqual(c._usage_report(),
+                         {'transientcount': 0,
+                          'itemcount': 10,
+                          'permanentcount': 0})
+        # write + reads
+        c = QueryCache(ceiling=20)
+        for n in xrange(4):
+            for x in xrange(10):
+                c[x] = x
+                c[x]
+        self.assertEqual(c._usage_report(),
+                         {'transientcount': 10,
+                          'itemcount': 10,
+                          'permanentcount': 0})
+        c = QueryCache(ceiling=20)
+        for n in xrange(17):
+            for x in xrange(10):
+                c[x] = x
+                c[x]
+        self.assertEqual(c._usage_report(),
+                         {'transientcount': 0,
+                          'itemcount': 10,
+                          'permanentcount': 10})
+        c = QueryCache(ceiling=20)
+        for n in xrange(17):
+            for x in xrange(10):
+                c[x] = x
+                if n % 2:
+                    c[x]
+                if x % 2:
+                    c[x]
+        self.assertEqual(c._usage_report(),
+                         {'transientcount': 5,
+                          'itemcount': 10,
+                          'permanentcount': 5})
 
 class UStringIOTC(TestCase):
     def test_boolean_value(self):
@@ -67,7 +116,7 @@
         # XXX
         self.assertEqual(l[4], (1, 3))
 
-        self.failIf(RepeatList(0, None))
+        self.assertFalse(RepeatList(0, None))
 
     def test_slice(self):
         l = RepeatList(3, (1, 3))
@@ -159,9 +208,17 @@
         self.assertEqual(self.encode(TestCase), 'null')
 
 class HTMLHeadTC(CubicWebTC):
+
+    def htmlhead(self, datadir_url):
+        req = self.request()
+        base_url = u'http://test.fr/data/'
+        req.datadir_url = base_url
+        head = HTMLHead(req)
+        return head
+
     def test_concat_urls(self):
         base_url = u'http://test.fr/data/'
-        head = HTMLHead(base_url)
+        head = self.htmlhead(base_url)
         urls = [base_url + u'bob1.js',
                 base_url + u'bob2.js',
                 base_url + u'bob3.js']
@@ -171,7 +228,7 @@
 
     def test_group_urls(self):
         base_url = u'http://test.fr/data/'
-        head = HTMLHead(base_url)
+        head = self.htmlhead(base_url)
         urls_spec = [(base_url + u'bob0.js', None),
                      (base_url + u'bob1.js', None),
                      (u'http://ext.com/bob2.js', None),
@@ -196,7 +253,7 @@
 
     def test_getvalue_with_concat(self):
         base_url = u'http://test.fr/data/'
-        head = HTMLHead(base_url)
+        head = self.htmlhead(base_url)
         head.add_js(base_url + u'bob0.js')
         head.add_js(base_url + u'bob1.js')
         head.add_js(u'http://ext.com/bob2.js')
@@ -224,20 +281,22 @@
         self.assertEqual(result, expected)
 
     def test_getvalue_without_concat(self):
-        base_url = u'http://test.fr/data/'
-        head = HTMLHead()
-        head.add_js(base_url + u'bob0.js')
-        head.add_js(base_url + u'bob1.js')
-        head.add_js(u'http://ext.com/bob2.js')
-        head.add_js(u'http://ext.com/bob3.js')
-        head.add_css(base_url + u'bob4.css')
-        head.add_css(base_url + u'bob5.css')
-        head.add_css(base_url + u'bob6.css', 'print')
-        head.add_css(base_url + u'bob7.css', 'print')
-        head.add_ie_css(base_url + u'bob8.css')
-        head.add_ie_css(base_url + u'bob9.css', 'print', u'[if lt IE 7]')
-        result = head.getvalue()
-        expected = u"""<head>
+        self.config.global_set_option('concat-resources', False)
+        try:
+            base_url = u'http://test.fr/data/'
+            head = self.htmlhead(base_url)
+            head.add_js(base_url + u'bob0.js')
+            head.add_js(base_url + u'bob1.js')
+            head.add_js(u'http://ext.com/bob2.js')
+            head.add_js(u'http://ext.com/bob3.js')
+            head.add_css(base_url + u'bob4.css')
+            head.add_css(base_url + u'bob5.css')
+            head.add_css(base_url + u'bob6.css', 'print')
+            head.add_css(base_url + u'bob7.css', 'print')
+            head.add_ie_css(base_url + u'bob8.css')
+            head.add_ie_css(base_url + u'bob9.css', 'print', u'[if lt IE 7]')
+            result = head.getvalue()
+            expected = u"""<head>
 <link rel="stylesheet" type="text/css" media="all" href="http://test.fr/data/bob4.css"/>
 <link rel="stylesheet" type="text/css" media="all" href="http://test.fr/data/bob5.css"/>
 <link rel="stylesheet" type="text/css" media="print" href="http://test.fr/data/bob6.css"/>
@@ -253,7 +312,9 @@
 <script type="text/javascript" src="http://ext.com/bob3.js"></script>
 </head>
 """
-        self.assertEqual(result, expected)
+            self.assertEqual(result, expected)
+        finally:
+            self.config.global_set_option('concat-resources', True)
 
 class DocTest(DocTest):
     from cubicweb import utils as module