Request to add a cast configuration option

[IanMitchell]

I wanted to file an issue for the discussion we had on Twitter about this problem!

When using the bigint type with PlanetScale or other HTTP drivers there needs to be a translation to convert a bigint into a JSON serializable value. With drizzle-orm, this is accomplished with the cast optional config parameter:

function inflate(field: Field, value: string | null) {
	if (field.type === "INT64" || field.type === "UINT64") {
		return BigInt(value ?? 0);
	}

	return cast(field, value);
}

const client = new Client({
	host: process.env.DATABASE_HOST,
	username: process.env.DATABASE_USERNAME,
	password: process.env.DATABASE_PASSWORD,
	cast: inflate,
});

However when using drizzle-kit, this option doesn't appear to exist. This results in errors when trying to create a table migration with a bigint column that has a default value set on it (JavaScript doesn't know how to serialize the value into JSON).

flags: bigint("flags", { mode: "bigint", unsigned: true }).notNull().default(0n)

You can kind of work around this via .$defaultFn(() => 0n), but you lose out on your database schema enforcing a non-null value. Ideally a cast option would be added to the drizzle-kit configuration options that would allow me to pass in the same inflate function!