Add test for #3880

spacy/tests/regression/test_issue3880.py

@@ -0,0 +1,23 @@
+# coding: utf8
+from __future__ import unicode_literals
+from spacy.lang.en import English
+import pytest
+
+
+@pytest.mark.xfail
+def test_issue3880():
+    """Test that `nlp.pipe()` works when an empty string ends the batch.
+
+    Fixed in v7.0.5 of Thinc.
+    """
+    texts = ["hello", "world", "", ""]
+    nlp = English()
+    nlp.add_pipe(nlp.create_pipe("parser"))
+    nlp.add_pipe(nlp.create_pipe("ner"))
+    nlp.add_pipe(nlp.create_pipe("tagger"))
+    nlp.get_pipe("parser").add_label("dep")
+    nlp.get_pipe("ner").add_label("PERSON")
+    nlp.get_pipe("tagger").add_label("NN")
+    nlp.begin_training()
+    for doc in nlp.pipe(texts):
+        pass