Migration: @kubb/plugin-ts

Part of the v4 → v5 migration guide. See the full option reference in @kubb/plugin-ts.

Removed: mapper

v4 kubb.config.ts

pluginTs({ mapper: { status: 'string' } })

Use printer.nodes to override specific schema-type renderers, or macros to rewrite AST nodes before printing.

Renamed: transformers.name

resolver.resolveTypeName replaces transformers.name.

Moved to adapterOas

dateType, integerType, unknownType, emptySchemaType, enumSuffix, and contentType moved to adapterOas. See Migration: @kubb/adapter-oas.

Changed: enum options grouped under one object

The loose enumType, enumTypeSuffix, and enumKeyCasing options now live inside one enum object, and a new enum.constCasing sets the casing of the generated const. The old enumType: 'asPascalConst' is gone, so reach for constCasing: 'pascalCase' instead.

v4 (old)	v5 (new)
enumType: 'asConst'	enum: { type: 'asConst' }
enumType: 'asPascalConst'	enum: { type: 'asConst', constCasing: 'pascalCase' }
enumTypeSuffix: 'Value'	enum: { typeSuffix: 'Value' }
enumKeyCasing: 'screamingSnakeCase'	enum: { keyCasing: 'screamingSnakeCase' }

v4 kubb.config.ts

import { defineConfig } from '@kubb/core'
import { pluginTs } from '@kubb/plugin-ts'

export default defineConfig({
  input: { path: './petstore.yaml' },
  output: { path: './src/gen' },
  plugins: [
    pluginTs({
      enumType: 'asConst',
      enumTypeSuffix: 'Key',
      enumKeyCasing: 'none',
    }),
  ],
})

v5 kubb.config.ts

import { defineConfig } from 'kubb'
import { pluginTs } from '@kubb/plugin-ts'

export default defineConfig({
  input: { path: './petstore.yaml' },
  output: { path: './src/gen' },
  plugins: [
    pluginTs({
      enum: { type: 'asConst', constCasing: 'camelCase', typeSuffix: 'Key', keyCasing: 'none' },
    }),
  ],
})

TIP

Set constCasing: 'pascalCase' together with typeSuffix: '' to emit a const and a type that share the schema's exact name. This is the convention most hand-written codebases use, so migrating an existing project keeps every annotation and value reference working.

pluginTs({ enum: { type: 'asConst', constCasing: 'pascalCase', typeSuffix: '' } })

export const VehicleType = {
  Sedan: 'Sedan',
  SUV: 'SUV',
} as const

export type VehicleType = (typeof VehicleType)[keyof typeof VehicleType]

Generated output

Enums: object literal instead of enum

v5 emits a const-asserted object plus a *Key type union. This drops the runtime cost of a TypeScript enum and stays tree-shakable.

v4

export enum ParamsStatusEnum {
  placed = 'placed',
  approved = 'approved',
  delivered = 'delivered',
}

status: ParamsStatusEnum

v5

export enum orderParamsStatusEnum {
  placed = 'placed',
  approved = 'approved',
  delivered = 'delivered',
}

status: OrderParamsStatusEnumKey

• Enum names are now operation-scoped (orderParamsStatusEnum, customerParamsStatusEnum, …) instead of suffix-deduplicated (ParamsStatusEnum, ParamsStatusEnum2, …), so the numeric collisions are gone.
• Configure enum on pluginTs when you want enum, constEnum, literal, or a different const and type casing.

int64 maps to bigint by default

adapterOas now defaults integerType to 'bigint', so OpenAPI fields with format: int64 generate bigint instead of number.

- petId?: number
+ petId?: bigint

Set integerType: 'number' on adapterOas to restore the previous output.

Open string unions use (string & {})

To keep IntelliSense suggestions, v5 writes the known TypeScript trick.

- status?: 'accepted' | string
+ status?: 'accepted' | (string & {})

JSDoc

• @type integer | undefined, int64 → @type integer | undefined. The format suffix is removed, since the schema documents the format rather than the type comment.
• @example is emitted from the OpenAPI example field.
• Object schemas now carry an @type object JSDoc tag.

Discriminated unions are factored

Fields shared by every variant of a oneOf/anyOf move into a common object:

- export type Pet =
-   | { id?: number; name: string; status?: StatusEnum; ... }
-   | { id?: number; name: string; status?: StatusEnum; ... }
+ export type Pet = ({ ... } | { ... }) & {
+   id?: number
+   name: string
+   status?: PetStatusEnumKey
+   ...
+ }