TST: added a basic unit test for merge entities function

unittests/test_apiutils.py

@@ -254,5 +254,20 @@ def test_copy_entities():
 
 
 def test_merge_entities():
-    # TODO: add test
-    pass
+    r = db.Record(name="A")
+    r.add_parent(name="B")
+    r.add_property(name="C", value=4, importance="OBLIGATORY")
+    r.add_property(name="D", value=[3, 4, 7], importance="OBLIGATORY")
+    r.description = "A fancy test record"
+
+    r2 = db.Record()
+    r2.add_property(name="F", value="text")
+    merge_entities(r2, r)
+    assert r2.get_parents()[0].name == "B"
+    assert r2.get_property("C").name == "C"
+    assert r2.get_property("C").value == 4
+    assert r2.get_property("D").name == "D"
+    assert r2.get_property("D").value == [3, 4, 7]
+
+    assert r2.get_property("F").name == "F"
+    assert r2.get_property("F").value == "text"