Support Database(memory=True) for in-memory databases

tests/conftest.py

@@ -1,16 +1,15 @@
 from sqlite_utils import Database
-from sqlite_utils.utils import sqlite3
 import pytest
 
 
 @pytest.fixture
 def fresh_db():
-    return Database(sqlite3.connect(":memory:"))
+    return Database(memory=True)
 
 
 @pytest.fixture
 def existing_db():
-    database = Database(sqlite3.connect(":memory:"))
+    database = Database(memory=True)
     database.conn.executescript(
         """
         CREATE TABLE foo (text TEXT);

tests/test_create.py

@@ -727,3 +727,10 @@ def test_create_table_numpy(fresh_db):
             "np.uint8": 8,
         }
     ] == list(fresh_db["types"].rows)
+
+
+def test_cannot_provide_both_filename_and_memory():
+    with pytest.raises(
+        AssertionError, match="Either specify a filename_or_conn or pass memory=True"
+    ):
+        db = Database("/tmp/foo.db", memory=True)