Connection validator not honoring :test => false

[normelton]

When connecting to a database, I am passing the parameter :test => false parameter to avoid connecting right away. But when I add the connection_validator plugin, it seems that the parameter is ignored and Sequel is connecting to the database immediately.

Presumably because of

sequel/lib/sequel/extensions/connection_validator.rb

Line 80 in bdeb862

pool.db.send(:valid_connection_sql)

Is there a reason that SQL needs to be precached? Is there a way to suppress this behavior?

[jeremyevans]

The SQL is precached so it is always available and precalculated. You could do the following before loading the extension:

# Or whatever SQL is valid for your database.
def DB.valid_connection_sql = "SELECT NULL"

Note that the :test => false option is working as expected. It prevents checking out a database connection during the Database object initialization. If there are other things you are doing with the Database that require a connection, then Sequel will attempt to connect at that point.

I'm not sure the precaching is required on all Database adapters that Sequel supports. However, it is required on some of them. If the SQL isn't precached, then Sequel would need to try to generate it, but the connection_validator extension calls it when trying to checkout a connection, so you would end up with infinite recursion if it wasn't precached in that case. I can say if the adapter you are using it checks out a connection when calling valid_connection_sql the first time (which is what is happening in your case), then it definitely would not be safe to skip precaching it.

[normelton]

Ahh I see. A static string would work! Thanks!