docs: add Bun.SQL support

Kysely's built-in PGliteDialect uses the same introspector as PostgreSQL, so KyselyTypegenPostgresDialect works with it as-is.

.github/workflows/ci.yml

@@ -15,18 +15,25 @@ jobs:
       TZ: "Europe/Paris"
       DO_NOT_TRACK: "1"
     steps:
-      - uses: "actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd" # v6.0.2
+      - uses: "actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1" # v7.0.1
 
       - name: "Setup Node.js"
-        uses: "actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e" # v6.4.0
+        uses: "actions/setup-node@820762786026740c76f36085b0efc47a31fe5020" # v7.0.0
         with:
-          node-version: "24.15.0"
+          node-version: "24.16.0"
           cache: "npm"
       - run: "node --version"
 
+      - name: "Setup Bun"
+        uses: "oven-sh/setup-bun@0c5077e51419868618aeaa5fe8019c62421857d6" # v2.2.0
+        with:
+          bun-version: "1.4.3"
+      - run: "bun --revision"
+
       - run: "npm clean-install"
       # - run: "node --run lint:typescript" # already covered by oxlint
       - run: "node --run lint:oxlint"
       - run: "node --run lint:oxfmt"
       - run: "node --run test"
+      - run: "node --run test:bun"
       - run: "node --run build"

.github/workflows/release.yml

@@ -17,15 +17,15 @@ jobs:
       pull-requests: "write"
       id-token: "write"
     steps:
-      - uses: "actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd" # v6.0.2
+      - uses: "actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1" # v7.0.1
         with:
           fetch-depth: 0
           persist-credentials: false
 
       - name: "Setup Node.js"
-        uses: "actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e" # v6.4.0
+        uses: "actions/setup-node@820762786026740c76f36085b0efc47a31fe5020" # v7.0.0
         with:
-          node-version: "24.15.0"
+          node-version: "24.16.0"
           registry-url: "https://registry.npmjs.org"
           package-manager-cache: false
 

CONTRIBUTING.md

@@ -47,6 +47,7 @@ node --run lint:oxfmt
 
 # Tests
 node --run test
+node --run test:bun
 
 # Build
 node --run build

README.md

@@ -16,7 +16,7 @@ Why `kysely-typegen` if there is already `kysely-codegen`? Comparison:
 | **Dependencies**              | 35 total                                 | 0 (no runtime dependencies)                                                         |
 | **Type**                      | CLI                                      | Library/Programmatic Usage                                                          |
 | **Code Size/Maintainability** | Heavy                                    | Lightweight/Simple and straightforward (string manipulation instead of complex AST) |
-| **Database Support**          | PostgreSQL, MySQL, SQLite, MSSQL, LibSQL | PostgreSQL, MySQL, SQLite (**can be easily extended to more**)                      |
+| **Database Support**          | PostgreSQL, MySQL, SQLite, MSSQL, LibSQL | PostgreSQL, PGlite, MySQL, SQLite (**can be easily extended to more**)              |
 
 `kysely-typegen` is a **library** (not a CLI), which means you are in control of where and how to run it, and is designed to be **extensible**, easy to add support for more database dialects.
 
@@ -50,7 +50,7 @@ Create your Kysely database instance and export a `databaseTypegen` for the scri
 
 #### PostgreSQL
 
-`KyselyTypegenPostgresDialect` works with any Kysely PostgreSQL dialect, including the built-in [`PostgresDialect`](https://kysely.dev/docs/dialects/postgres) (using [`pg`](https://npmx.dev/package/pg)) and [`PostgresJSDialect`](https://npmx.dev/package/kysely-postgres-js) (using [`postgres`](https://npmx.dev/package/postgres)). The example below uses `kysely-postgres-js`.
+`KyselyTypegenPostgresDialect` works with any Kysely PostgreSQL dialect, including the built-in [`PostgresDialect`](https://kysely.dev/docs/dialects/postgres) (using [`pg`](https://npmx.dev/package/pg)) and [`PostgresJSDialect`](https://npmx.dev/package/kysely-postgres-js) (using [`postgres`](https://npmx.dev/package/postgres) or [`Bun.SQL`](#bunsql)). The example below uses `kysely-postgres-js`.
 
 ```sh
 npm install kysely-postgres-js postgres
@@ -79,6 +79,62 @@ export const database = new Kysely<DB>({ dialect })
 export const databaseTypegen = new KyselyTypegenPostgresDialect({ database })
 ```
 
+#### Bun.SQL
+
+With [Bun](https://bun.com/), pass the built-in [`Bun.SQL`](https://bun.com/docs/runtime/sql) client to `PostgresJSDialect` instead of `postgres`, so no extra driver is required.
+
+```sh
+bun add kysely-postgres-js
+```
+
+```ts
+// database.ts
+import Bun from "bun"
+import { Kysely } from "kysely"
+import { PostgresJSDialect } from "kysely-postgres-js"
+import { KyselyTypegenPostgresDialect } from "kysely-typegen/postgres"
+
+import type { DB } from "./codegen.ts"
+
+const dialect = new PostgresJSDialect({
+  postgres: new Bun.SQL({
+    adapter: "postgres",
+    database: process.env["DATABASE_NAME"] ?? "database",
+    hostname: process.env["DATABASE_HOST"] ?? "localhost",
+    username: process.env["DATABASE_USER"] ?? "user",
+    password: process.env["DATABASE_PASSWORD"] ?? "password",
+    port: Number.parseInt(process.env["DATABASE_PORT"] ?? "5432", 10),
+  }),
+})
+
+export const database = new Kysely<DB>({ dialect })
+export const databaseTypegen = new KyselyTypegenPostgresDialect({ database })
+```
+
+#### PGlite
+
+[PGlite](https://pglite.dev/) is PostgreSQL compiled to WebAssembly that runs in-process. Use Kysely's built-in [`PGliteDialect`](https://kysely-org.github.io/kysely-apidoc/classes/PGliteDialect.html) with `KyselyTypegenPostgresDialect`: PGlite is introspected exactly like PostgreSQL. Because `kysely-typegen` is a library, you pass it the `Kysely` instance you already have, so it works with in-process databases like PGlite, including in-memory ones, without a connection string or CLI-specific dialect support.
+
+```sh
+npm install @electric-sql/pglite
+```
+
+```ts
+// database.ts
+import { PGlite } from "@electric-sql/pglite"
+import { Kysely, PGliteDialect } from "kysely"
+import { KyselyTypegenPostgresDialect } from "kysely-typegen/postgres"
+
+import type { DB } from "./codegen.ts"
+
+const dialect = new PGliteDialect({
+  pglite: new PGlite(process.env["DATABASE_PATH"] ?? "./pgdata"),
+})
+
+export const database = new Kysely<DB>({ dialect })
+export const databaseTypegen = new KyselyTypegenPostgresDialect({ database })
+```
+
 #### MySQL
 
 ```sh
@@ -155,6 +211,12 @@ Run with Node.js (using `--env-file` to load environment variables, no `dotenv`
 node --env-file=.env scripts/typegen.ts
 ```
 
+Or run with Bun (loads `.env` automatically):
+
+```sh
+bun scripts/typegen.ts
+```
+
 ### Using the type definitions
 
 Import `DB` into `new Kysely<DB>`, and you're done!
@@ -168,6 +230,19 @@ const rows = await database.selectFrom("User").selectAll().execute()
 
 Fully type-safe queries derived from your actual database schema.
 
+### Column comments
+
+Column comments (`COMMENT ON COLUMN` in PostgreSQL, `COMMENT '...'` in MySQL) are emitted as JSDoc above the column, so they show up in your editor on hover:
+
+```ts
+export interface Users {
+  /** Contact email address. */
+  email: string | null
+}
+```
+
+SQLite has no column comments, so none are generated.
+
 ## Extending to other database dialects
 
 `kysely-typegen` ships with `KyselyTypegenPostgresDialect`, `KyselyTypegenMySQLDialect`, and `KyselyTypegenSQLiteDialect`, but you can add support for any database by extending the abstract `KyselyTypegenDialect` class.

package.json

@@ -36,28 +36,31 @@
     "lint:oxlint": "oxlint .",
     "lint:oxfmt": "oxfmt . --check",
     "oxfmt": "oxfmt .",
-    "test": "node --test",
+    "test": "node --test \"src/_test/*.test.ts\"",
+    "test:bun": "bun test src/_test/bun",
     "build": "tsdown",
     "release": "semantic-release"
   },
   "devDependencies": {
-    "@testcontainers/mysql": "12.0.0",
-    "@testcontainers/postgresql": "12.0.0",
-    "@types/better-sqlite3": "7.6.13",
-    "@types/node": "25.9.1",
-    "@types/pg": "8.20.0",
-    "better-sqlite3": "12.10.0",
-    "kysely": "0.29.2",
-    "kysely-postgres-js": "3.0.0",
-    "mysql2": "3.22.3",
-    "oxfmt": "0.51.0",
-    "oxlint": "1.66.0",
-    "oxlint-tsgolint": "0.23.0",
-    "pg": "8.21.0",
+    "@electric-sql/pglite": "0.5.8",
+    "@testcontainers/mysql": "12.2.0",
+    "@testcontainers/postgresql": "12.2.0",
+    "@types/better-sqlite3": "9.6.0",
+    "@types/bun": "1.4.3",
+    "@types/node": "26.6.4",
+    "@types/pg": "8.23.1",
+    "better-sqlite3": "13.0.3",
+    "kysely": "0.29.6",
+    "kysely-postgres-js": "5.0.1",
+    "mysql2": "3.24.5",
+    "oxfmt": "0.71.0",
+    "oxlint": "1.86.0",
+    "oxlint-tsgolint": "7.0.2003",
+    "pg": "8.23.1",
     "postgres": "3.4.9",
-    "semantic-release": "25.0.3",
-    "tsdown": "0.22.0",
-    "typescript": "6.0.3"
+    "semantic-release": "25.0.9",
+    "tsdown": "0.23.0",
+    "typescript": "7.0.2"
   },
   "peerDependencies": {
     "kysely": ">=0.29.0"

src/_test/__snapshots__/mysql.test.ts.snapshot

@@ -62,10 +62,16 @@ exports[`typegen MySQL > generate types matching snapshot 1`] = `
     "}",
     "",
     "export interface Orders {",
+    "  /**",
+    "   * Total amount in cents.",
+    "   *",
+    "   * Excludes taxes.",
+    "   */",
     "  amountCents: number",
     "  createdAt: Generated<Timestamp>",
     "  currency: Generated<\\"EUR\\" | \\"GBP\\" | \\"USD\\">",
     "  id: Generated<Int8>",
+    "  /** Free text, may contain *\\\\/ characters. */",
     "  note: string | null",
     "  status: Generated<\\"cancelled\\" | \\"paid\\" | \\"pending\\" | \\"shipped\\">",
     "  userId: number",
@@ -73,6 +79,7 @@ exports[`typegen MySQL > generate types matching snapshot 1`] = `
     "",
     "export interface Users {",
     "  createdAt: Generated<Timestamp>",
+    "  /** Contact email address. */",
     "  email: string | null",
     "  id: Generated<number>",
     "  isActive: Generated<number>",

src/_test/__snapshots__/postgres.test.ts.snapshot

@@ -1,3 +1,121 @@
+exports[`typegen PGlite > generate types matching snapshot 1`] = `
+{
+  "lines": [
+    "// This file was automatically generated by \`kysely-typegen\`.",
+    "// Do not edit this file manually.",
+    "",
+    "import type { ColumnType } from \\"kysely\\"",
+    "",
+    "export type Generated<T> = T extends ColumnType<infer S, infer I, infer U> ? ColumnType<S, I | undefined, U> : ColumnType<T, T | undefined, T>",
+    "",
+    "export type Timestamp = ColumnType<Date, Date | string, Date | string>",
+    "",
+    "export type Numeric = ColumnType<string, number | string, number | string>",
+    "",
+    "export type Int8 = ColumnType<string, bigint | number | string, bigint | number | string>",
+    "",
+    "export type Json = JsonValue",
+    "",
+    "export type JsonArray = JsonValue[]",
+    "",
+    "export interface JsonObject {",
+    "  [x: string]: JsonValue | undefined",
+    "}",
+    "",
+    "export type JsonPrimitive = boolean | number | string | null",
+    "",
+    "export type JsonValue = JsonArray | JsonObject | JsonPrimitive",
+    "",
+    "export type Currency = \\"EUR\\" | \\"GBP\\" | \\"USD\\"",
+    "",
+    "export type OrderStatus = \\"cancelled\\" | \\"paid\\" | \\"pending\\" | \\"shipped\\"",
+    "",
+    "export type UserRole = \\"admin\\" | \\"guest\\" | \\"member\\"",
+    "",
+    "export interface AllTypes {",
+    "  colBit: string",
+    "  colBool: boolean",
+    "  colBoolDefault: Generated<boolean>",
+    "  colBoolNullable: boolean | null",
+    "  colBox: string",
+    "  colBpchar: string",
+    "  colBytea: Buffer",
+    "  colCidr: string",
+    "  colDate: Timestamp",
+    "  colFloat4: number",
+    "  colFloat8: number",
+    "  colInet: string",
+    "  colInt2: number",
+    "  colInt4: number",
+    "  colInt8: Int8",
+    "  colJson: Json",
+    "  colJsonb: Json",
+    "  colJsonbDefault: Generated<Json>",
+    "  colLine: string",
+    "  colLseg: string",
+    "  colMacaddr: string",
+    "  colMoney: string",
+    "  colNumeric: Numeric",
+    "  colOid: number",
+    "  colPath: string",
+    "  colPoint: unknown",
+    "  colPolygon: string",
+    "  colText: string",
+    "  colTextNullable: string | null",
+    "  colTime: string",
+    "  colTimestamp: Timestamp",
+    "  colTimestampDefault: Generated<Timestamp>",
+    "  colTimestamptz: Timestamp",
+    "  colTimetz: string",
+    "  colTsquery: string",
+    "  colTsvector: string",
+    "  colUuid: string",
+    "  colVarbit: string",
+    "  colVarchar: string",
+    "  colXml: string",
+    "  createdAt: Generated<Timestamp>",
+    "  id: Generated<string>",
+    "  updatedAt: Timestamp | null",
+    "}",
+    "",
+    "export interface Orders {",
+    "  /**",
+    "   * Total amount in cents.",
+    "   *",
+    "   * Excludes taxes.",
+    "   */",
+    "  amountCents: number",
+    "  createdAt: Generated<Timestamp>",
+    "  currency: Generated<Currency>",
+    "  id: Generated<Int8>",
+    "  /** Free text, may contain *\\\\/ characters. */",
+    "  note: string | null",
+    "  status: Generated<OrderStatus>",
+    "  userId: string",
+    "}",
+    "",
+    "export interface Users {",
+    "  createdAt: Generated<Timestamp>",
+    "  /** Contact email address. */",
+    "  email: string | null",
+    "  id: Generated<string>",
+    "  isActive: Generated<boolean>",
+    "  role: Generated<UserRole>",
+    "  username: string",
+    "}",
+    "",
+    "export interface DB {",
+    "  AllTypes: AllTypes",
+    "  Orders: Orders",
+    "  Users: Users",
+    "}"
+  ],
+  "tablesCount": 3,
+  "enumsCount": 3,
+  "inlineEnumsCount": 0
+}
+`;
+
 exports[`typegen PostgreSQL > generate types matching snapshot (kysely-postgres-js) 1`] = `
 {
   "lines": [
@@ -79,10 +197,16 @@ exports[`typegen PostgreSQL > generate types matching snapshot (kysely-postgres-
     "}",
     "",
     "export interface Orders {",
+    "  /**",
+    "   * Total amount in cents.",
+    "   *",
+    "   * Excludes taxes.",
+    "   */",
     "  amountCents: number",
     "  createdAt: Generated<Timestamp>",
     "  currency: Generated<Currency>",
     "  id: Generated<Int8>",
+    "  /** Free text, may contain *\\\\/ characters. */",
     "  note: string | null",
     "  status: Generated<OrderStatus>",
     "  userId: string",
@@ -90,6 +214,7 @@ exports[`typegen PostgreSQL > generate types matching snapshot (kysely-postgres-
     "",
     "export interface Users {",
     "  createdAt: Generated<Timestamp>",
+    "  /** Contact email address. */",
     "  email: string | null",
     "  id: Generated<string>",
     "  isActive: Generated<boolean>",
@@ -190,10 +315,16 @@ exports[`typegen PostgreSQL > generate types matching snapshot (pg) 1`] = `
     "}",
     "",
     "export interface Orders {",
+    "  /**",
+    "   * Total amount in cents.",
+    "   *",
+    "   * Excludes taxes.",
+    "   */",
     "  amountCents: number",
     "  createdAt: Generated<Timestamp>",
     "  currency: Generated<Currency>",
     "  id: Generated<Int8>",
+    "  /** Free text, may contain *\\\\/ characters. */",
     "  note: string | null",
     "  status: Generated<OrderStatus>",
     "  userId: string",
@@ -201,6 +332,7 @@ exports[`typegen PostgreSQL > generate types matching snapshot (pg) 1`] = `
     "",
     "export interface Users {",
     "  createdAt: Generated<Timestamp>",
+    "  /** Contact email address. */",
     "  email: string | null",
     "  id: Generated<string>",
     "  isActive: Generated<boolean>",

src/_test/_postgres.ts

@@ -0,0 +1,200 @@
+import type { Kysely } from "kysely"
+import { sql } from "kysely"
+
+export const POSTGRES_IMAGE =
+  "docker.io/postgres:18.4@sha256:f7ce845ee6873dd84be93c9828fe0d1fab0f9707dc9ac569694657398b290bce"
+
+export const createSchema = async (database: Kysely<any>): Promise<void> => {
+  await database.schema.createType("Currency").asEnum(["EUR", "USD", "GBP"]).execute()
+  await database.schema.createType("UserRole").asEnum(["admin", "member", "guest"]).execute()
+  await database.schema
+    .createType("OrderStatus")
+    .asEnum(["pending", "paid", "shipped", "cancelled"])
+    .execute()
+
+  await database.schema
+    .createTable("AllTypes")
+    .addColumn("id", "uuid", (column) => {
+      return column
+        .notNull()
+        .primaryKey()
+        .defaultTo(sql`uuidv7()`)
+    })
+    .addColumn("colBool", "boolean", (column) => {
+      return column.notNull()
+    })
+    .addColumn("colBoolNullable", "boolean")
+    .addColumn("colBoolDefault", "boolean", (column) => {
+      return column.notNull().defaultTo(false)
+    })
+    .addColumn("colInt2", "smallint", (column) => {
+      return column.notNull()
+    })
+    .addColumn("colInt4", "integer", (column) => {
+      return column.notNull()
+    })
+    .addColumn("colInt8", "bigint", (column) => {
+      return column.notNull()
+    })
+    .addColumn("colFloat4", "real", (column) => {
+      return column.notNull()
+    })
+    .addColumn("colFloat8", "double precision", (column) => {
+      return column.notNull()
+    })
+    .addColumn("colNumeric", sql`numeric(12, 2)`, (column) => {
+      return column.notNull()
+    })
+    .addColumn("colMoney", sql`money`, (column) => {
+      return column.notNull()
+    })
+    .addColumn("colText", "text", (column) => {
+      return column.notNull()
+    })
+    .addColumn("colVarchar", "varchar(255)", (column) => {
+      return column.notNull()
+    })
+    .addColumn("colBpchar", sql`char(10)`, (column) => {
+      return column.notNull()
+    })
+    .addColumn("colBytea", "bytea", (column) => {
+      return column.notNull()
+    })
+    .addColumn("colDate", "date", (column) => {
+      return column.notNull()
+    })
+    .addColumn("colTime", "time", (column) => {
+      return column.notNull()
+    })
+    .addColumn("colTimetz", sql`timetz`, (column) => {
+      return column.notNull()
+    })
+    .addColumn("colTimestamp", "timestamp", (column) => {
+      return column.notNull()
+    })
+    .addColumn("colTimestamptz", "timestamptz", (column) => {
+      return column.notNull()
+    })
+    .addColumn("colJson", "json", (column) => {
+      return column.notNull()
+    })
+    .addColumn("colJsonb", "jsonb", (column) => {
+      return column.notNull()
+    })
+    .addColumn("colUuid", "uuid", (column) => {
+      return column.notNull()
+    })
+    .addColumn("colInet", sql`inet`, (column) => {
+      return column.notNull()
+    })
+    .addColumn("colCidr", sql`cidr`, (column) => {
+      return column.notNull()
+    })
+    .addColumn("colMacaddr", sql`macaddr`, (column) => {
+      return column.notNull()
+    })
+    .addColumn("colBit", sql`bit(8)`, (column) => {
+      return column.notNull()
+    })
+    .addColumn("colVarbit", sql`varbit(16)`, (column) => {
+      return column.notNull()
+    })
+    .addColumn("colXml", sql`xml`, (column) => {
+      return column.notNull()
+    })
+    .addColumn("colTsvector", sql`tsvector`, (column) => {
+      return column.notNull()
+    })
+    .addColumn("colTsquery", sql`tsquery`, (column) => {
+      return column.notNull()
+    })
+    .addColumn("colPoint", sql`point`, (column) => {
+      return column.notNull()
+    })
+    .addColumn("colLine", sql`line`, (column) => {
+      return column.notNull()
+    })
+    .addColumn("colLseg", sql`lseg`, (column) => {
+      return column.notNull()
+    })
+    .addColumn("colBox", sql`box`, (column) => {
+      return column.notNull()
+    })
+    .addColumn("colPath", sql`path`, (column) => {
+      return column.notNull()
+    })
+    .addColumn("colPolygon", sql`polygon`, (column) => {
+      return column.notNull()
+    })
+    .addColumn("colOid", sql`oid`, (column) => {
+      return column.notNull()
+    })
+    .addColumn("colTextNullable", "text")
+    .addColumn("colJsonbDefault", "jsonb", (column) => {
+      return column.notNull().defaultTo(sql`'{}'::jsonb`)
+    })
+    .addColumn("colTimestampDefault", "timestamp", (column) => {
+      return column.notNull().defaultTo(sql`now()`)
+    })
+    .addColumn("createdAt", "timestamptz", (column) => {
+      return column.notNull().defaultTo(sql`now()`)
+    })
+    .addColumn("updatedAt", "timestamptz")
+    .execute()
+
+  await database.schema
+    .createTable("Users")
+    .addColumn("id", "uuid", (column) => {
+      return column
+        .notNull()
+        .primaryKey()
+        .defaultTo(sql`uuidv7()`)
+    })
+    .addColumn("username", "varchar(50)", (column) => {
+      return column.notNull().unique()
+    })
+    .addColumn("email", "text")
+    .addColumn("role", sql`"UserRole"`, (column) => {
+      return column.notNull().defaultTo("member")
+    })
+    .addColumn("isActive", "boolean", (column) => {
+      return column.notNull().defaultTo(true)
+    })
+    .addColumn("createdAt", "timestamptz", (column) => {
+      return column.notNull().defaultTo(sql`now()`)
+    })
+    .execute()
+
+  await database.schema
+    .createTable("Orders")
+    .addColumn("id", "bigserial", (column) => {
+      return column.notNull().primaryKey()
+    })
+    .addColumn("userId", "uuid", (column) => {
+      return column.notNull().references("Users.id")
+    })
+    .addColumn("status", sql`"OrderStatus"`, (column) => {
+      return column.notNull().defaultTo("pending")
+    })
+    .addColumn("currency", sql`"Currency"`, (column) => {
+      return column.notNull().defaultTo("EUR")
+    })
+    .addColumn("amountCents", "integer", (column) => {
+      return column.notNull()
+    })
+    .addColumn("note", "text")
+    .addColumn("createdAt", "timestamptz", (column) => {
+      return column.notNull().defaultTo(sql`now()`)
+    })
+    .execute()
+
+  await sql`comment on column ${sql.ref("Users.email")} is ${sql.lit("Contact email address.")}`.execute(
+    database,
+  )
+  await sql`comment on column ${sql.ref("Orders.amountCents")} is ${sql.lit("Total amount in cents.\n\nExcludes taxes.")}`.execute(
+    database,
+  )
+  await sql`comment on column ${sql.ref("Orders.note")} is ${sql.lit("Free text, may contain */ characters.")}`.execute(
+    database,
+  )
+}

src/_test/bun/__snapshots__/postgres.test.ts.snap

@@ -0,0 +1,119 @@
+// Bun Snapshot v1, https://bun.sh/docs/test/snapshots
+
+exports[`typegen PostgreSQL (Bun.SQL) generate types matching snapshot 1`] = `
+{
+  "enumsCount": 3,
+  "inlineEnumsCount": 0,
+  "lines": [
+    "// This file was automatically generated by \`kysely-typegen\`.",
+    "// Do not edit this file manually.",
+    "",
+    "import type { ColumnType } from "kysely"",
+    "",
+    "export type Generated<T> = T extends ColumnType<infer S, infer I, infer U> ? ColumnType<S, I | undefined, U> : ColumnType<T, T | undefined, T>",
+    "",
+    "export type Timestamp = ColumnType<Date, Date | string, Date | string>",
+    "",
+    "export type Numeric = ColumnType<string, number | string, number | string>",
+    "",
+    "export type Int8 = ColumnType<string, bigint | number | string, bigint | number | string>",
+    "",
+    "export type Json = JsonValue",
+    "",
+    "export type JsonArray = JsonValue[]",
+    "",
+    "export interface JsonObject {",
+    "  [x: string]: JsonValue | undefined",
+    "}",
+    "",
+    "export type JsonPrimitive = boolean | number | string | null",
+    "",
+    "export type JsonValue = JsonArray | JsonObject | JsonPrimitive",
+    "",
+    "export type Currency = "EUR" | "GBP" | "USD"",
+    "",
+    "export type OrderStatus = "cancelled" | "paid" | "pending" | "shipped"",
+    "",
+    "export type UserRole = "admin" | "guest" | "member"",
+    "",
+    "export interface AllTypes {",
+    "  colBit: string",
+    "  colBool: boolean",
+    "  colBoolDefault: Generated<boolean>",
+    "  colBoolNullable: boolean | null",
+    "  colBox: string",
+    "  colBpchar: string",
+    "  colBytea: Buffer",
+    "  colCidr: string",
+    "  colDate: Timestamp",
+    "  colFloat4: number",
+    "  colFloat8: number",
+    "  colInet: string",
+    "  colInt2: number",
+    "  colInt4: number",
+    "  colInt8: Int8",
+    "  colJson: Json",
+    "  colJsonb: Json",
+    "  colJsonbDefault: Generated<Json>",
+    "  colLine: string",
+    "  colLseg: string",
+    "  colMacaddr: string",
+    "  colMoney: string",
+    "  colNumeric: Numeric",
+    "  colOid: number",
+    "  colPath: string",
+    "  colPoint: unknown",
+    "  colPolygon: string",
+    "  colText: string",
+    "  colTextNullable: string | null",
+    "  colTime: string",
+    "  colTimestamp: Timestamp",
+    "  colTimestampDefault: Generated<Timestamp>",
+    "  colTimestamptz: Timestamp",
+    "  colTimetz: string",
+    "  colTsquery: string",
+    "  colTsvector: string",
+    "  colUuid: string",
+    "  colVarbit: string",
+    "  colVarchar: string",
+    "  colXml: string",
+    "  createdAt: Generated<Timestamp>",
+    "  id: Generated<string>",
+    "  updatedAt: Timestamp | null",
+    "}",
+    "",
+    "export interface Orders {",
+    "  /**",
+    "   * Total amount in cents.",
+    "   *",
+    "   * Excludes taxes.",
+    "   */",
+    "  amountCents: number",
+    "  createdAt: Generated<Timestamp>",
+    "  currency: Generated<Currency>",
+    "  id: Generated<Int8>",
+    "  /** Free text, may contain *\\/ characters. */",
+    "  note: string | null",
+    "  status: Generated<OrderStatus>",
+    "  userId: string",
+    "}",
+    "",
+    "export interface Users {",
+    "  createdAt: Generated<Timestamp>",
+    "  /** Contact email address. */",
+    "  email: string | null",
+    "  id: Generated<string>",
+    "  isActive: Generated<boolean>",
+    "  role: Generated<UserRole>",
+    "  username: string",
+    "}",
+    "",
+    "export interface DB {",
+    "  AllTypes: AllTypes",
+    "  Orders: Orders",
+    "  Users: Users",
+    "}",
+  ],
+  "tablesCount": 3,
+}
+`;

src/_test/bun/postgres.test.ts

@@ -0,0 +1,54 @@
+import type { StartedPostgreSqlContainer } from "@testcontainers/postgresql"
+import { PostgreSqlContainer } from "@testcontainers/postgresql"
+import Bun from "bun"
+import { afterAll, beforeAll, describe, expect, it } from "bun:test"
+import { Kysely } from "kysely"
+import { PostgresJSDialect } from "kysely-postgres-js"
+
+import { KyselyTypegenPostgresDialect } from "../../postgres.ts"
+import { createSchema, POSTGRES_IMAGE } from "../_postgres.ts"
+
+const CONTAINER_START_TIMEOUT_MILLISECONDS = 120_000
+
+describe("typegen PostgreSQL (Bun.SQL)", () => {
+  let container: StartedPostgreSqlContainer
+  let database: Kysely<any>
+
+  beforeAll(async () => {
+    container = await new PostgreSqlContainer(POSTGRES_IMAGE).start()
+    database = new Kysely<any>({
+      dialect: new PostgresJSDialect({
+        postgres: new Bun.SQL({
+          adapter: "postgres",
+          database: container.getDatabase(),
+          hostname: container.getHost(),
+          port: container.getPort(),
+          username: container.getUsername(),
+          password: container.getPassword(),
+        }),
+      }),
+    })
+    await createSchema(database)
+  }, CONTAINER_START_TIMEOUT_MILLISECONDS)
+
+  afterAll(async () => {
+    await database.destroy()
+    await container.stop()
+  })
+
+  it("generate types matching snapshot", async () => {
+    // Arrange - Given
+    const databaseTypegen = new KyselyTypegenPostgresDialect({ database })
+
+    // Act - When
+    const result = await databaseTypegen.typegen()
+
+    // Assert - Then
+    expect({
+      lines: result.lines,
+      tablesCount: result.tables.length,
+      enumsCount: result.enums.length,
+      inlineEnumsCount: result.inlineEnums.size,
+    }).toMatchSnapshot()
+  })
+})

src/_test/mysql.test.ts

@@ -117,7 +117,9 @@ const createSchema = async (database: Kysely<any>): Promise<void> => {
     .addColumn("username", "varchar(50)", (column) => {
       return column.notNull().unique()
     })
-    .addColumn("email", "text")
+    .addColumn("email", "text", (column) => {
+      return column.modifyEnd(sql`comment ${sql.lit("Contact email address.")}`)
+    })
     .addColumn("role", sql`enum('admin','member','guest')`, (column) => {
       return column.notNull().defaultTo("member")
     })
@@ -144,9 +146,13 @@ const createSchema = async (database: Kysely<any>): Promise<void> => {
       return column.notNull().defaultTo("EUR")
     })
     .addColumn("amountCents", "integer", (column) => {
-      return column.notNull()
+      return column
+        .notNull()
+        .modifyEnd(sql`comment ${sql.lit("Total amount in cents.\n\nExcludes taxes.")}`)
+    })
+    .addColumn("note", "text", (column) => {
+      return column.modifyEnd(sql`comment ${sql.lit("Free text, may contain */ characters.")}`)
     })
-    .addColumn("note", "text")
     .addColumn("createdAt", "timestamp", (column) => {
       return column.notNull().defaultTo(sql`current_timestamp`)
     })

src/_test/postgres.test.ts

@@ -1,202 +1,16 @@
+import { PGlite } from "@electric-sql/pglite"
 import type { StartedPostgreSqlContainer } from "@testcontainers/postgresql"
 import { PostgreSqlContainer } from "@testcontainers/postgresql"
-import { Kysely, PostgresDialect, sql } from "kysely"
+import { Kysely, PGliteDialect, PostgresDialect } from "kysely"
 import { PostgresJSDialect } from "kysely-postgres-js"
 import { after, before, describe, it } from "node:test"
 import pg from "pg"
 import postgres from "postgres"
 
 import { KyselyTypegenPostgresDialect } from "../postgres.ts"
+import { createSchema, POSTGRES_IMAGE } from "./_postgres.ts"
 import "./_setup.ts"
 
-const POSTGRES_IMAGE =
-  "docker.io/postgres:18.4@sha256:f7ce845ee6873dd84be93c9828fe0d1fab0f9707dc9ac569694657398b290bce"
-
-const createSchema = async (database: Kysely<any>): Promise<void> => {
-  await database.schema.createType("Currency").asEnum(["EUR", "USD", "GBP"]).execute()
-  await database.schema.createType("UserRole").asEnum(["admin", "member", "guest"]).execute()
-  await database.schema
-    .createType("OrderStatus")
-    .asEnum(["pending", "paid", "shipped", "cancelled"])
-    .execute()
-
-  await database.schema
-    .createTable("AllTypes")
-    .addColumn("id", "uuid", (column) => {
-      return column
-        .notNull()
-        .primaryKey()
-        .defaultTo(sql`uuidv7()`)
-    })
-    .addColumn("colBool", "boolean", (column) => {
-      return column.notNull()
-    })
-    .addColumn("colBoolNullable", "boolean")
-    .addColumn("colBoolDefault", "boolean", (column) => {
-      return column.notNull().defaultTo(false)
-    })
-    .addColumn("colInt2", "smallint", (column) => {
-      return column.notNull()
-    })
-    .addColumn("colInt4", "integer", (column) => {
-      return column.notNull()
-    })
-    .addColumn("colInt8", "bigint", (column) => {
-      return column.notNull()
-    })
-    .addColumn("colFloat4", "real", (column) => {
-      return column.notNull()
-    })
-    .addColumn("colFloat8", "double precision", (column) => {
-      return column.notNull()
-    })
-    .addColumn("colNumeric", sql`numeric(12, 2)`, (column) => {
-      return column.notNull()
-    })
-    .addColumn("colMoney", sql`money`, (column) => {
-      return column.notNull()
-    })
-    .addColumn("colText", "text", (column) => {
-      return column.notNull()
-    })
-    .addColumn("colVarchar", "varchar(255)", (column) => {
-      return column.notNull()
-    })
-    .addColumn("colBpchar", sql`char(10)`, (column) => {
-      return column.notNull()
-    })
-    .addColumn("colBytea", "bytea", (column) => {
-      return column.notNull()
-    })
-    .addColumn("colDate", "date", (column) => {
-      return column.notNull()
-    })
-    .addColumn("colTime", "time", (column) => {
-      return column.notNull()
-    })
-    .addColumn("colTimetz", sql`timetz`, (column) => {
-      return column.notNull()
-    })
-    .addColumn("colTimestamp", "timestamp", (column) => {
-      return column.notNull()
-    })
-    .addColumn("colTimestamptz", "timestamptz", (column) => {
-      return column.notNull()
-    })
-    .addColumn("colJson", "json", (column) => {
-      return column.notNull()
-    })
-    .addColumn("colJsonb", "jsonb", (column) => {
-      return column.notNull()
-    })
-    .addColumn("colUuid", "uuid", (column) => {
-      return column.notNull()
-    })
-    .addColumn("colInet", sql`inet`, (column) => {
-      return column.notNull()
-    })
-    .addColumn("colCidr", sql`cidr`, (column) => {
-      return column.notNull()
-    })
-    .addColumn("colMacaddr", sql`macaddr`, (column) => {
-      return column.notNull()
-    })
-    .addColumn("colBit", sql`bit(8)`, (column) => {
-      return column.notNull()
-    })
-    .addColumn("colVarbit", sql`varbit(16)`, (column) => {
-      return column.notNull()
-    })
-    .addColumn("colXml", sql`xml`, (column) => {
-      return column.notNull()
-    })
-    .addColumn("colTsvector", sql`tsvector`, (column) => {
-      return column.notNull()
-    })
-    .addColumn("colTsquery", sql`tsquery`, (column) => {
-      return column.notNull()
-    })
-    .addColumn("colPoint", sql`point`, (column) => {
-      return column.notNull()
-    })
-    .addColumn("colLine", sql`line`, (column) => {
-      return column.notNull()
-    })
-    .addColumn("colLseg", sql`lseg`, (column) => {
-      return column.notNull()
-    })
-    .addColumn("colBox", sql`box`, (column) => {
-      return column.notNull()
-    })
-    .addColumn("colPath", sql`path`, (column) => {
-      return column.notNull()
-    })
-    .addColumn("colPolygon", sql`polygon`, (column) => {
-      return column.notNull()
-    })
-    .addColumn("colOid", sql`oid`, (column) => {
-      return column.notNull()
-    })
-    .addColumn("colTextNullable", "text")
-    .addColumn("colJsonbDefault", "jsonb", (column) => {
-      return column.notNull().defaultTo(sql`'{}'::jsonb`)
-    })
-    .addColumn("colTimestampDefault", "timestamp", (column) => {
-      return column.notNull().defaultTo(sql`now()`)
-    })
-    .addColumn("createdAt", "timestamptz", (column) => {
-      return column.notNull().defaultTo(sql`now()`)
-    })
-    .addColumn("updatedAt", "timestamptz")
-    .execute()
-
-  await database.schema
-    .createTable("Users")
-    .addColumn("id", "uuid", (column) => {
-      return column
-        .notNull()
-        .primaryKey()
-        .defaultTo(sql`uuidv7()`)
-    })
-    .addColumn("username", "varchar(50)", (column) => {
-      return column.notNull().unique()
-    })
-    .addColumn("email", "text")
-    .addColumn("role", sql`"UserRole"`, (column) => {
-      return column.notNull().defaultTo("member")
-    })
-    .addColumn("isActive", "boolean", (column) => {
-      return column.notNull().defaultTo(true)
-    })
-    .addColumn("createdAt", "timestamptz", (column) => {
-      return column.notNull().defaultTo(sql`now()`)
-    })
-    .execute()
-
-  await database.schema
-    .createTable("Orders")
-    .addColumn("id", "bigserial", (column) => {
-      return column.notNull().primaryKey()
-    })
-    .addColumn("userId", "uuid", (column) => {
-      return column.notNull().references("Users.id")
-    })
-    .addColumn("status", sql`"OrderStatus"`, (column) => {
-      return column.notNull().defaultTo("pending")
-    })
-    .addColumn("currency", sql`"Currency"`, (column) => {
-      return column.notNull().defaultTo("EUR")
-    })
-    .addColumn("amountCents", "integer", (column) => {
-      return column.notNull()
-    })
-    .addColumn("note", "text")
-    .addColumn("createdAt", "timestamptz", (column) => {
-      return column.notNull().defaultTo(sql`now()`)
-    })
-    .execute()
-}
-
 describe("typegen PostgreSQL", () => {
   let container: StartedPostgreSqlContainer
   let database: Kysely<any>
@@ -266,3 +80,36 @@ describe("typegen PostgreSQL", () => {
     })
   })
 })
+
+describe("typegen PGlite", () => {
+  let database: Kysely<any>
+
+  before(async () => {
+    database = new Kysely<any>({
+      dialect: new PGliteDialect({
+        pglite: new PGlite(),
+      }),
+    })
+    await createSchema(database)
+  })
+
+  after(async () => {
+    await database.destroy()
+  })
+
+  it("generate types matching snapshot", async (testContext) => {
+    // Arrange - Given
+    const databaseTypegen = new KyselyTypegenPostgresDialect({ database })
+
+    // Act - When
+    const result = await databaseTypegen.typegen()
+
+    // Assert - Then
+    testContext.assert.snapshot({
+      lines: result.lines,
+      tablesCount: result.tables.length,
+      enumsCount: result.enums.length,
+      inlineEnumsCount: result.inlineEnums.size,
+    })
+  })
+})

src/index.ts

@@ -73,6 +73,24 @@ export abstract class KyselyTypegenDialect {
     return scalars[dataType] ?? "unknown"
   }
 
+  protected formatColumnComment(comment: string): string[] {
+    const trimmedComment = comment.trim()
+    if (trimmedComment.length === 0) {
+      return []
+    }
+    const lines = trimmedComment.replaceAll("*/", "*\\/").split(/\r?\n/u)
+    if (lines.length === 1) {
+      return [`  /** ${lines[0]} */`]
+    }
+    return [
+      "  /**",
+      ...lines.map((line) => {
+        return line.length === 0 ? "   *" : `   * ${line}`
+      }),
+      "   */",
+    ]
+  }
+
   public getTablesTypegen(
     tables: TableMetadata[],
     enums: EnumMetadata[],
@@ -94,6 +112,9 @@ export abstract class KyselyTypegenDialect {
         if (column.hasDefaultValue || column.isAutoIncrementing) {
           columnType = `Generated<${columnType}>`
         }
+        if (column.comment != null) {
+          result.push(...this.formatColumnComment(column.comment))
+        }
         result.push(`  ${column.name}: ${columnType}`)
       }
       result.push("}", "")
@@ -146,14 +167,16 @@ export abstract class KyselyTypegenDialect {
     tables: TableMetadata[]
   }> {
     const [tables, { enums, inlineEnums }] = await Promise.all([this.getTables(), this.getEnums()])
-    const lines: string[] = [...PREAMBLE_LINES]
-    lines.push(...this.getEnumsTypegen(enums))
-    lines.push(...this.getTablesTypegen(tables, enums, inlineEnums))
-    lines.push("export interface DB {")
-    for (const table of tables) {
-      lines.push(`  ${table.name}: ${table.name}`)
-    }
-    lines.push("}")
+    const lines: string[] = [
+      ...PREAMBLE_LINES,
+      ...this.getEnumsTypegen(enums),
+      ...this.getTablesTypegen(tables, enums, inlineEnums),
+      "export interface DB {",
+      ...tables.map((table) => {
+        return `  ${table.name}: ${table.name}`
+      }),
+      "}",
+    ]
     return { lines, enums, inlineEnums, tables }
   }
 }

src/mysql.ts

@@ -52,12 +52,12 @@ export class KyselyTypegenMySQLDialect extends KyselyTypegenDialect {
       ])
       .where("columns.TABLE_SCHEMA", "=", sql`database()`)
       .where("columns.DATA_TYPE", "in", ["enum", "set"])
+      .$castTo<{ tableName: string; columnName: string; columnType: string }>()
       .execute()
 
     const inline = new Map<string, string[]>()
     for (const row of rows) {
-      const data = row as { tableName: string; columnName: string; columnType: string }
-      inline.set(`${data.tableName}.${data.columnName}`, parseMysqlEnumColumnType(data.columnType))
+      inline.set(`${row.tableName}.${row.columnName}`, parseMysqlEnumColumnType(row.columnType))
     }
     return { named: [], inline }
   }

tsconfig.json

@@ -29,6 +29,6 @@
     "resolveJsonModule": true,
 
     "lib": ["ESNext"],
-    "types": ["@types/node"]
+    "types": ["@types/node", "@types/bun"]
   }
 }