TST: Add test for ambiguous retrieval

... and mark it as xfail until dealt with on server side

tests/test_error_stuff.py

@@ -31,7 +31,8 @@ Created on 19.02.2015.
 
 """
 import caosdb as h
-from caosdb.exceptions import (EntityDoesNotExistError, EntityError,
+from caosdb.exceptions import (AmbiguousEntityError,
+                               EntityDoesNotExistError, EntityError,
                                EntityHasNoDatatypeError,
                                TransactionError, UniqueNamesError,
                                UnqualifiedParentsError,
@@ -86,6 +87,23 @@ def test_retrieval_exception_raised():
     assert ee.entity.has_errors()
 
 
+@pytest.mark.xfail(reason=("Error treatment on server-side"
+                           "has to be implemented first."))
+def test_ambiguous_retrieval():
+    """Test if a TransactionError containing an AmbiguousEntityError is
+    raised correctly if there are two possible candidates.
+
+    """
+    h.RecordType(name="TestType").insert()
+    h.Record(name="TestRec").add_parent(name="TestType").insert()
+    # Insert twice, so unique=False
+    h.Record(name="TestRec").add_parent(name="TestType").insert(unique=False)
+    with pytest.raises(TransactionError) as te:
+        h.Record(name="TestRec").retrieve()
+    assert te.value.has_error(AmbiguousEntityError)
+    assert te.value.errors[0].entity.name == "TestRec"
+
+
 def test_insertion_no_exception_raised():
     """Test whether insertion fails but no error is raised."""
     p = h.Property(name="TestNoTypeProperty").insert(