diff --git a/product/ERP5Type/tests/testJSONEncoder.py b/product/ERP5Type/tests/testJSONEncoder.py
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+++ b/product/ERP5Type/tests/testJSONEncoder.py
@@ -0,0 +1,86 @@
+##############################################################################
+#
+# Copyright (c) 2008 Nexedi SA and Contributors. All Rights Reserved.
+#                     Lucas Carvalho <lucas@nexedi.com>
+#
+# WARNING: This program as such is intended to be used by professional
+# programmers who take the whole responsability of assessing all potential
+# consequences resulting from its eventual inadequacies and bugs
+# End users who are looking for a ready-to-use solution with commercial
+# garantees and support are strongly adviced to contract a Free Software
+# Service Company
+#
+# This program is Free Software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+#
+##############################################################################
+
+import unittest
+from Products.ERP5Type.JSONEncoder import encodeInJson
+
+class TestJSONEncoder(unittest.TestCase):
+
+  def test_encodeAListType(self):
+    my_list = [1, 2, 3, 'foo', 'bar']
+    result = encodeInJson(my_list)
+    self.assertEquals(result, '[1, 2, 3, "foo", "bar"]')
+
+  def test_encodeATupleType(self):
+    my_tuple = (1, 2, 3, 'foo', None,)
+    result = encodeInJson(my_tuple)
+    self.assertEquals(result, '[1, 2, 3, "foo", null]')
+
+  def test_encodeADictionaryType(self):
+    my_dict = { 'foo': 'bar',
+                1: 2,
+                'bar': [1, 2, 'bar'],
+                2: None,
+                3: float(3),
+                4: True,
+                5: False,
+              }
+    expected_result = '{"1": 2, "2": null, "3": 3.0, "bar": [1, 2, "bar"], '\
+                      '"5": false, "4": true, "foo": "bar"}'
+    result = encodeInJson(my_dict)
+    self.assertEquals(result, expected_result)
+                    
+  def test_encodeAStringType(self):
+    result = encodeInJson('This is my string.')
+    self.assertEquals(result, '"This is my string."')
+
+  def test_encodeAIntType(self):
+    result = encodeInJson(int(3))
+    self.assertEquals(result, '3')
+
+  def test_encodeANoneType(self):
+    result = encodeInJson(None)
+    self.assertEquals(result, 'null')
+
+  def test_encodeAFloatType(self):
+    result = encodeInJson(float(3))
+    self.assertEquals(result, '3.0')
+
+  def test_encodeALongType(self):
+    result = encodeInJson(long(3))
+    self.assertEquals(result, '3')
+
+  def test_encodeABooleanType(self):
+    result_true = encodeInJson(True)
+    result_false = encodeInJson(False)
+
+    self.assertEquals(result_true, 'true')
+    self.assertEquals(result_false, 'false')
+
+if __name__ == '__main__':
+  unittest.main()