contract.ts

import type {MigrationParams} from '../types'

export type UmzugStorage<Ctx = unknown> = {
  /**
   * Logs migration to be considered as executed.
   */
  logMigration: (params: MigrationParams<Ctx>) => Promise<void>

  /**
   * Unlogs migration (makes it to be considered as pending).
   */
  unlogMigration: (params: MigrationParams<Ctx>) => Promise<void>

  /**
   * Gets list of executed migrations.
   */
  executed: (meta: Pick<MigrationParams<Ctx>, 'context'>) => Promise<string[]>
}

export function isUmzugStorage(arg: Partial<UmzugStorage>): arg is UmzugStorage {
  return (
    arg &&
    typeof arg.logMigration === 'function' &&
    typeof arg.unlogMigration === 'function' &&
    typeof arg.executed === 'function'
  )
}

export const verifyUmzugStorage = (arg: Partial<UmzugStorage>): UmzugStorage => {
  if (!isUmzugStorage(arg)) {
    throw new Error(`Invalid umzug storage`)
  }

  return arg
}