Refactored connection logic to database.connect()

datasette/app.py

@@ -470,20 +470,7 @@ class Datasette:
         def in_thread():
             conn = getattr(connections, db_name, None)
             if not conn:
-                db = self.databases[db_name]
+                conn = self.databases[db_name].connect()
-                if db.is_memory:
-                    conn = sqlite3.connect(":memory:")
-                else:
-                    # mode=ro or immutable=1?
-                    if db.is_mutable:
-                        qs = "mode=ro"
-                    else:
-                        qs = "immutable=1"
-                    conn = sqlite3.connect(
-                        "file:{}?{}".format(db.path, qs),
-                        uri=True,
-                        check_same_thread=False,
-                    )
                 self.prepare_connection(conn)
                 setattr(connections, db_name, conn)
             return fn(conn)

datasette/database.py

@@ -33,6 +33,18 @@ class Database:
                     for key, value in self.ds.inspect_data[self.name]["tables"].items()
                 }
 
+    def connect(self):
+        if self.is_memory:
+            return sqlite3.connect(":memory:")
+        # mode=ro or immutable=1?
+        if self.is_mutable:
+            qs = "mode=ro"
+        else:
+            qs = "immutable=1"
+        return sqlite3.connect(
+            "file:{}?{}".format(self.path, qs), uri=True, check_same_thread=False
+        )
+
     @property
     def size(self):
         if self.is_memory: