Migration fails with: "TypeError: Cannot redefine property: then"

[EmptySpace99]

I created the following migration file:

import { Kysely, sql } from 'kysely'

export async function up(db: Kysely<any>): Promise<void> {
  await db.schema
    .createTable('person')
    .addColumn('id', 'serial', (col) => col.primaryKey())
    .addColumn('first_name', 'varchar', (col) => col.notNull())
    .addColumn('last_name', 'varchar')
    .addColumn('gender', 'varchar(50)', (col) => col.notNull())
    .addColumn('created_at', 'timestamp', (col) =>
      col.defaultTo(sql`now()`).notNull()
    )
    .execute()
}

export async function down(db: Kysely<any>): Promise<void> {
  await db.schema.dropTable('person').execute()
}

And then I tried to run the migration with npm run kysely migrate:up but it failed with the following error message:

Migration failed with TypeError: Cannot redefine property: then

If I remove the following code and retry the migration, it completes successfully:

.addColumn('created_at', 'timestamp', (col) =>
  col.defaultTo(sql`now()`).notNull()
)

In my kysely.config.ts file I have the following code:

import { Kysely, PostgresDialect } from "kysely";
import { defineConfig } from "kysely-ctl";
import { Pool } from 'pg'

const connectionString = process.env.DATABASE_URL ?? ''

const dialect = new PostgresDialect({
  pool: new Pool({
    connectionString: connectionString
  })
})

export default defineConfig({
  dialect: dialect,
  migrations: {
    migrationFolder: 'migrations',
  },
});

It seems a bug to me but I'm not sure if I'm missing something else.

[igalklebanov]

Hey 👋

Try adding up() to and running this migration using npx tsx <filepath>, does it still happen? Can you provide a reproduction repository?

[EmptySpace99]

I created one: https://github.com/EmptySpace99/test-kysely-ctl

[igalklebanov]

Thanks for the reproduction. I was able to debug and think that https://github.com/kysely-org/kysely/pull/1031 should solve it - it did on my machine.

You should patch kysely in your project for now following the changes in that PR using something like https://www.npmjs.com/package/patch-package OR https://pnpm.io/cli/patch.

This doesn't happen when turning the project to ESM ("type": "module" in package.json), so you could migrate instead.

[EmptySpace99]

Thank you so much, effectively turning the project to ESM fix the problem. Probably this is the easiest fix for now, hope that the real fix will be merged soon. 💪🏻