Add regression test for #1654

spacy/tests/regression/test_issue1654.py

@@ -0,0 +1,17 @@
+# coding: utf8
+from __future__ import unicode_literals
+
+import pytest
+
+from ...language import Language
+from ...vocab import Vocab
+
+
+@pytest.mark.xfail
+def test_issue1654():
+    nlp = Language(Vocab())
+    assert not nlp.pipeline
+    nlp.add_pipe(lambda doc: doc, name='1')
+    nlp.add_pipe(lambda doc: doc, name='2', after='1')
+    nlp.add_pipe(lambda doc: doc, name='3', after='2')
+    assert nlp.pipe_names == ['1', '2', '3']