[MIG] base external dbsource

* Migration of base_external_dbsource to odoo 9.0

* Fixing test error

* Moving test from yaml to python

* Fixing pylint error in test class

* Placeholder added to connection string text zone

* improving test coverage

base_external_dbsource/tests/__init__.py

@@ -0,0 +1,3 @@
+# -*- encoding: utf-8 -*-
+
+from . import test_create_dbsource

base_external_dbsource/tests/test_create_dbsource.py

@@ -0,0 +1,58 @@
+# -*- coding: utf-8 -*-
+
+from openerp.exceptions import Warning as UserError
+from openerp.tests import common
+import logging
+
+
+class TestCreateDbsource(common.TransactionCase):
+    """Test class for base_external_dbsource."""
+
+    def test_create_dbsource(self):
+        """source creation should succeed."""
+        dbsource = self.env.ref('base_external_dbsource.demo_postgre')
+        try:
+            dbsource.connection_test()
+        except UserError as e:
+            logging.warning("Log = " + str(e))
+            self.assertTrue(u'Everything seems properly set up!' in str(e))
+
+    def test_create_dbsource_failed(self):
+        """source creation without connection string should failed."""
+        dbsource = self.env.ref('base_external_dbsource.demo_postgre')
+
+        # Connection without connection_string
+        dbsource.conn_string = ""
+        try:
+            dbsource.connection_test()
+        except UserError as e:
+            logging.warning("Log = " + str(e))
+            self.assertTrue(u'Here is what we got instead:' in str(e))
+
+    def test_create_dbsource_without_connector_failed(self):
+        """source creation with other connector should failed."""
+        dbsource = self.env.ref('base_external_dbsource.demo_postgre')
+
+        # Connection to mysql
+        try:
+            dbsource.connector = "mysql"
+            dbsource.connection_test()
+        except ValueError as e:
+            logging.warning("Log = " + str(e))
+            self.assertTrue(u'Wrong value for' in str(e))
+
+        # Connection to mysql
+        try:
+            dbsource.connector = "pyodbc"
+            dbsource.connection_test()
+        except ValueError as e:
+            logging.warning("Log = " + str(e))
+            self.assertTrue(u'Wrong value for' in str(e))
+
+        # Connection to oracle
+        try:
+            dbsource.connector = "cx_Oracle"
+            dbsource.connection_test()
+        except ValueError as e:
+            logging.warning("Log = " + str(e))
+            self.assertTrue(u'Wrong value for' in str(e))