Fix urlsplit python3.7.6

rasa/core/tracker_store.py

@@ -30,6 +30,8 @@
 
 logger = logging.getLogger(__name__)
 
+SQLITE_SCHEME = "sqlite"
+
 
 class TrackerStore:
     """Class to hold all of the TrackerStore classes"""
@@ -639,17 +641,20 @@ def get_db_url(
             URL ready to be used with an SQLAlchemy `Engine` object.
 
         """
-        from urllib.parse import urlsplit
+        from urllib import parse
         from sqlalchemy.engine.url import URL
 
         # Users might specify a url in the host
-        parsed = urlsplit(host or "")
-        if parsed.scheme:
+        parsed = parse.urlsplit(host or "")
+        # We have to check `scheme` and `hostname` because Python 3.7.6 parses strings
+        # like `localhost:1234` as a URL with scheme `localhost`. However, `sqlite:///`
+        # a special case because it doesn't require a hostname.
+        if parsed.scheme and (parsed.hostname or parsed.scheme == SQLITE_SCHEME):
             return host
 
         if host:
             # add fake scheme to properly parse components
-            parsed = urlsplit("schema://" + host)
+            parsed = parse.urlsplit(f"scheme://{host}")
 
             # users might include the port in the url
             port = parsed.port or port

tests/core/test_tracker_stores.py

@@ -260,6 +260,7 @@ def pickle_serialise_tracker(_tracker):
         "postgresql://localhost",
         "postgresql://localhost:5432",
         "postgresql://user:secret@localhost",
+        "sqlite:///",
     ],
 )
 def test_get_db_url_with_fully_specified_url(full_url: Text):
@@ -279,6 +280,11 @@ def test_get_db_url_with_port_in_host():
     )
 
 
+def test_db_get_url_with_sqlite():
+    expected = "sqlite:///rasa.db"
+    assert str(SQLTrackerStore.get_db_url(dialect="sqlite", db="rasa.db")) == expected
+
+
 def test_get_db_url_with_correct_host():
     expected = "postgresql://localhost:5005/mydb"