v0.30.0-beta.2

Hey 👋

0.30 season is upon us. pnpm i kysely@next and get a sneak peak into the future!

We've got a new transactionMode: 'per-run' | 'per-migration' | 'none' property you can pass to Migrator or it's methods.

• 'per-run' is the classic behavior you're used to where kysely wrap the entire run in a transaction when your dialect supports transactional DDL.
• 'per-migration' enables each migration to pick whether it runs in its own transaction or not. Just expose config: { transaction: false } from the module, right next to the up/down functions.
• 'none' means no transactions are used, which is similar to the now deprecated disableTransactions: true.

import * as fs from 'node:fs/promises'
import * as path from 'node:path'
import { FileMigrationProvider, Migrator } from 'kysely/migration'

const migrator = new Migrator({
  db,
  provider: new FileMigrationProvider({
    fs,
    migrationFolder: path.join(import.meta.dirname, 'migrations'),
  }),
  transactionMode: 'per-migration', // <-------------------------------
})

await migrator.migrateToLatest()

We've got a new defineMigration helper function that you can use to easily write your migrations and meet the contract requirements:

import { defineMigration } from 'kysely/migration'

export default defineMigration({
  up: async (db) => {
    // ...
  },

  config: { transaction: false }, // <--------------------
})

You can now use mysql2/promise, where in the past it would hang forever since we only supported the callback style of mysql2 root import.

We're trying various type-level solutions that provide compilation performance and type-safety improvements of Kysely, Transaction, ControlledTransaction and their readonly variants. QueryCreator, FunctionModule, MergeQueryBuilder too.

We've got a new stream method on RawBuilder that allows you to:

import { sql } from 'kysely'
import { db } from 'path/to/db'

for await (const row of sql`select * from person`.stream(db)) {
  // ...
}

🚀 Features

• feat(migrator): add migrateTo(name, { direction: 'Up' | 'Down' }) to enforce direction. by @igalklebanov in #1957
• feat(introspector): add where option for partial introspection. by @igalklebanov in #2005
• feat(introspector): add where option in getSchemas. by @igalklebanov in #2006
• feat(introspector): add comment property in table metadata. by @igalklebanov in #2008
• feat: stream raw query results. by @igalklebanov in #2037

PostgreSQL 🐘 / MSSQL 🥅

• feat: Per-migration transaction configuration by @lourd & @igalklebanov in #1671

PostgreSQL 🐘

• feat(postgres): support introspecting materialized views. by @igalklebanov in #2010

MySQL 🐬

• feat(mysql): support both mysql2 and mysql2/promise in MysqlDialect. by @igalklebanov in #1958
• feat(mysql): add withNonDefaultDatabases to support introspection of non-default databases. by @igalklebanov in #2007

SQLite 📘

• feat: deny passing BLOB-like columns to SQLite JSON helpers by @hwisu & @igalklebanov in #1698
• feat(sqlite): stream queries that return rows. by @igalklebanov in
  #2036

🐞 Bugfixes

• fix: reject database assignments with missing tables. by @igalklebanov in #2015
• fix: allow transactions with extra tables to satisfy narrower schemas. by @igalklebanov in #2017
• fix: accept Kysely instances with extra tables on TypeScript 5. by @igalklebanov in #2018
• fix: preserve column read and write types in assignments. by @igalklebanov in #2019
• fix: preserve controlled transaction column write assignability. by @igalklebanov in #2022
• fix: preserve generic table extension assignability. by @igalklebanov in #2025
• fix: allow ControlledTransaction<any> to satisfy Transaction<DB>. by @igalklebanov in #2027
• fix: preserve readonly schema guarantees during assignment. by @igalklebanov in #2029
• fix: allow compatible readonly transactions as database handles. by @igalklebanov in #2033
• fix: allow compatible readonly controlled transactions as parent handles. by @igalklebanov in #2034

📖 Documentation

• docs: correct DummyDriver execution JSDoc. by @igalklebanov in #2032

📦 CICD & Tooling

• test: add Vitest typechecking to TypeScript CI. by @igalklebanov in #2014

⚠️ Breaking Changes

• disableTransactions is deprecated. Use the new transactionMode: 'none', or transactionMode: 'per-migration' with combination of config: { transaction: false }.
• MySQL introspection now always excludes system databases - mysql, information_schema, performance_schema, sys and nbinfo tables will not be returned.
• You might start seeing invocations of some your custom helpers failing compilation now that Kysely, Transaction, ControlledTransaction and their readonly variants are compared more tightly. QueryCreator, FunctionModule, MergeQueryBuilder too. Please report these cases.

SQLite 📘

• Trying to pass records with BLOB columns in JSON helpers emits compile-time errors - e.g.

   KyselyTypeError<'SQLite does not support passing `BLOB` values to `json_object`. Cast to `TEXT`.'>

🐤 New Contributors

What's Changed

Full Changelog: v0.29.5...v0.30.0-beta.2