Add unit tests for negative test framework

Add basic test cases for generate_json and negative auto test.

Partially-implements: bp negative-tests
Change-Id: I52d376689c0eca0e732ec8a506039b4ef0e326fe
diff --git a/tempest/tests/negative/test_generate_json.py b/tempest/tests/negative/test_generate_json.py
new file mode 100644
index 0000000..a0aa088
--- /dev/null
+++ b/tempest/tests/negative/test_generate_json.py
@@ -0,0 +1,53 @@
+# Copyright 2014 Deutsche Telekom AG
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from tempest.common import generate_json as gen
+import tempest.test
+
+
+class TestGenerateJson(tempest.test.BaseTestCase):
+
+    fake_input_str = {"type": "string",
+                      "minLength": 2,
+                      "maxLength": 8,
+                      'results': {'gen_number': 404}}
+
+    fake_input_int = {"type": "integer",
+                      "maximum": 255,
+                      "minimum": 1}
+
+    fake_input_obj = {"type": "object",
+                      "properties": {"minRam": {"type": "integer"},
+                                     "diskName": {"type": "string"},
+                                     "maxRam": {"type": "integer", }
+                                     }
+                      }
+
+    def _validate_result(self, data):
+        self.assertTrue(isinstance(data, list))
+        for t in data:
+            self.assertTrue(isinstance(t, tuple))
+
+    def test_generate_invalid_string(self):
+        result = gen.generate_invalid(self.fake_input_str)
+        self._validate_result(result)
+
+    def test_generate_invalid_integer(self):
+        result = gen.generate_invalid(self.fake_input_int)
+        self._validate_result(result)
+
+    def test_generate_invalid_obj(self):
+        result = gen.generate_invalid(self.fake_input_obj)
+        self._validate_result(result)