Fix #284 as grouping

2 files changed, 7 insertions, 1 deletions

diff --git a/sqlparse/engine/grouping.py b/sqlparse/engine/grouping.py
index 42305c3..7cbcc6b 100644
--- a/sqlparse/engine/grouping.py
+++ b/sqlparse/engine/grouping.py
@@ -121,7 +121,7 @@ def group_as(tlist):
 
     def valid_next(token):
         ttypes = T.DML, T.DDL
-        return not imt(token, t=ttypes)
+        return not imt(token, t=ttypes) and token is not None
 
     def post(tlist, pidx, tidx, nidx):
         return pidx, nidx
diff --git a/tests/test_regressions.py b/tests/test_regressions.py
index b978071..ba908d3 100644
--- a/tests/test_regressions.py
+++ b/tests/test_regressions.py
@@ -314,3 +314,9 @@ def test_token_next_doesnt_ignore_skip_cm():
     sql = '--comment\nselect 1'
     tok = sqlparse.parse(sql)[0].token_next(-1, skip_cm=True)[1]
     assert tok.value == 'select'
+
+
+def test_issue284_as_grouping():
+    sql = 'SELECT x AS'
+    p = sqlparse.parse(sql)[0]
+    assert sql == str(p)