From 3243ddac8f699a69ce2e4e39ae80c62cfd30ad12 Mon Sep 17 00:00:00 2001
From: Yohei Tamura <tamuhey@gmail.com>
Date: Thu, 1 Oct 2020 21:01:52 +0900
Subject: [PATCH] Fix/span.sent (#6083)

* add fail test

* fix test

* fix span.sent

* Remove incorrect implicit check

Co-authored-by: Adriane Boyd <adrianeboyd@gmail.com>
---
 spacy/tests/doc/test_span.py | 20 +++++++++++++++++---
 spacy/tokens/span.pyx        |  5 ++---
 2 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/spacy/tests/doc/test_span.py b/spacy/tests/doc/test_span.py
index 107078df9..df41aedf5 100644
--- a/spacy/tests/doc/test_span.py
+++ b/spacy/tests/doc/test_span.py
@@ -174,19 +174,25 @@ def test_spans_by_character(doc):
     assert span1.end_char == span2.end_char
     assert span2.label_ == "GPE"
 
-    span2 = doc.char_span(span1.start_char, span1.end_char, label="GPE", alignment_mode="strict")
+    span2 = doc.char_span(
+        span1.start_char, span1.end_char, label="GPE", alignment_mode="strict"
+    )
     assert span1.start_char == span2.start_char
     assert span1.end_char == span2.end_char
     assert span2.label_ == "GPE"
 
     # alignment mode "contract"
-    span2 = doc.char_span(span1.start_char - 3, span1.end_char, label="GPE", alignment_mode="contract")
+    span2 = doc.char_span(
+        span1.start_char - 3, span1.end_char, label="GPE", alignment_mode="contract"
+    )
     assert span1.start_char == span2.start_char
     assert span1.end_char == span2.end_char
     assert span2.label_ == "GPE"
 
     # alignment mode "expand"
-    span2 = doc.char_span(span1.start_char + 1, span1.end_char, label="GPE", alignment_mode="expand")
+    span2 = doc.char_span(
+        span1.start_char + 1, span1.end_char, label="GPE", alignment_mode="expand"
+    )
     assert span1.start_char == span2.start_char
     assert span1.end_char == span2.end_char
     assert span2.label_ == "GPE"
@@ -318,3 +324,11 @@ def test_span_boundaries(doc):
         _ = span[-5]
     with pytest.raises(IndexError):
         _ = span[5]
+
+
+def test_sent(en_tokenizer):
+    doc = en_tokenizer("Check span.sent raises error if doc is not sentencized.")
+    span = doc[1:3]
+    assert not span.doc.is_sentenced
+    with pytest.raises(ValueError):
+        span.sent
diff --git a/spacy/tokens/span.pyx b/spacy/tokens/span.pyx
index 29b87fa8d..cf0775bae 100644
--- a/spacy/tokens/span.pyx
+++ b/spacy/tokens/span.pyx
@@ -391,8 +391,6 @@ cdef class Span:
         """RETURNS (Span): The sentence span that the span is a part of."""
         if "sent" in self.doc.user_span_hooks:
             return self.doc.user_span_hooks["sent"](self)
-        # This should raise if not parsed / no custom sentence boundaries
-        self.doc.sents
         # Use `sent_start` token attribute to find sentence boundaries
         cdef int n = 0
         if self.doc.is_sentenced:
@@ -402,13 +400,14 @@ cdef class Span:
                 start += -1
             # Find end of the sentence
             end = self.end
-            n = 0
             while end < self.doc.length and self.doc.c[end].sent_start != 1:
                 end += 1
                 n += 1
                 if n >= self.doc.length:
                     break
             return self.doc[start:end]
+        else:
+            raise ValueError(Errors.E030)
 
     @property
     def ents(self):