Expose config as a public property

[SevInf]

In Prisma's driver adapter for Planetscale, we need to be able to get database name from the connection string. Currently, url is not exposed as a public property. In this PR we solve this by exposing config object that we get from user through constructor.

[ayrton]

For the driver the connection URL is always https and naming the function connectionUrl might not be 100% accurate.

All we might need here is a get configUrl () { return config.url } or make config public.

For context is this a convenience method so you don't have to pass the database URL through PrismaPlanetScale and/or PrismaClient?

import { Client } from '@planetscale/database'
import { PrismaPlanetScale } from '@prisma/adapter-planetscale'
import { PrismaClient } from '@prisma/client'
import dotenv from 'dotenv'
import { fetch as undiciFetch } from 'undici'

dotenv.config()
const connectionString = `${process.env.DATABASE_URL}`

const client = new Client({ url: connectionString, fetch: undiciFetch })
const adapter = new PrismaPlanetScale(client)
const prisma = new PrismaClient({ adapter })

[SevInf]

Yes.
For driver adapters, we decided to leave configuration of a DB client to the user. That means that Client is already configured by the time any of our code is executed. At the same time, we need some information from the connection string to build our SQL queries: in MySQL case, this is the database name. We really don't want to require our users to supply it twice, and using different DB name than the one specified in the connection string does not make sense in our world. So, if it is already part of the connection string, it makes a perfect sense to take it from there.