I've found weird transaction behaviour on MYSQL. having

object TransactionTestTable: LongIdTable(){
    val foo = integer("foo").check { it greater 0 }
}

when I do

newSuspendedTransaction {
    TransactionTestTable.insert { it[foo] = 1 }
    throw IllegalStateException("FAIL")
}

the transaction performs a rollback correctly and nothing gets inserted into the table but when I do

newSuspendedTransaction {
    TransactionTestTable.insert { it[foo] = 1 }
    TransactionTestTable.insert { it[foo] = 0 }
}

the transaction still fails, but the first value gets inserted in the database. Is this intentional or a bug?

I have exactly the same problem. It seems that

newSuspendedTransaction

always commits at end and don't uses the parent transaction.

and where can I find this property in exposed?

you'd have to set it not in exposed but in your connector