DEV: added test for usage of empty strings

tests/test_empty_text_value.py

+#!/usr/bin/python2
+# encoding: utf-8
+#
+# This file is a part of the CaosDB Project.
+#
+# Copyright (C) 2019 Henrik tom Wörden
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 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 Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program. If not, see <https://www.gnu.org/licenses/>.
+#
+
+from nose.tools import assert_equals, with_setup
+
+import caosdb as db
+
+
+def setup():
+    rt = db.RecordType("Test")
+    rt.insert()
+    p = db.Property("te", datatype=db.TEXT)
+    p.insert()
+
+
+def teardown():
+    try:
+        db.execute_query("FIND Test*").delete()
+    except Exception as e:
+        print(e)
+    try:
+        db.execute_query("FIND te").delete()
+    except Exception as e:
+        print(e)
+
+
+@with_setup(setup, teardown)
+def test_deletion():
+    r = db.Record()
+    r.add_parent("Test")
+    r.add_property("te", value="leer")
+    r.insert()
+    assert_equals(db.execute_query("FIND Test with te='leer'")[0].id, r.id)
+    r.delete()
+    r = db.Record()
+    r.add_parent("Test")
+    r.add_property("te", value="")
+    r.insert()
+    assert_equals(db.execute_query("FIND Test with te=''")[0].id, r.id)
+    r.delete()