wrangler has been, basically from the beginning, a tool that uses toml. They are adding a system to parse JSON into an object that wrangler can use that matches the toml spec, but there may be some points that don't just workwrangler used to be written in Rust, which is why it started out with toml. And you can still run Workers entirely without writing JS(see #workerd, which isn't JS at all. And they are moving toward JSON configs nowe68dccd4-7bf7-4860-ba18-17978966ec10 is on the older alpha backend)error.cause into the top-level error soon. It might break a few folks who are exact string matching: no real way around this. Luck of an alpha error.cause around until open beta, then trim that up.migrations_dir with the cli? I'm working on a pages project and it doesn't have a wrangler.toml file. So I'm trying a script like npx wrangler d1 migrations apply <DB> --migrations-dir=<dir> but it's not working.error.cause 
.cause is standard, unfortunately 
[[ d1_databases ]]
binding = "__D1_BETA__DB_ONE"
database_name = "db-one"
database_id = "<someID>"
migrations_table = "d1_migrations"
migrations_dir = "d1_migrations/db-one"
[[ d1_databases ]]
binding = "__D1_BETA__DB_TWO"
database_name = "db-two"
database_id = "<someId>"
migrations_table = "d1_migrations"
migrations_dir = "d1_migrations/db-two"wranglerwranglerwranglertomltomltomlworkerde68dccd4-7bf7-4860-ba18-17978966ec10error.causeerror.causeerror.causeerrormigrations_dirnpx wrangler d1 migrations apply <DB> --migrations-dir=<dir>.cause