Prisma TypeScript Interfaces Generator

Common errors

• Error: Unknown generator option: 'omitRelations'.

  cause The `omitRelations` option (and `optionalRelations`) was removed in version 3.0.0.
  fix Replace `omitRelations` or `optionalRelations` with the new `relations` option. For example, use `relations = "none"` to omit all relations, or `relations = "optional"`.

• TS2304: Cannot find name 'BufferObject'.

  cause The built-in `BufferObject` and `ArrayObject` options for `bytesType` were removed in v3.0.0.
  fix Remove `bytesType = "BufferObject"` (or `ArrayObject`) from your generator configuration. If you need this behavior, define a custom type using the `customTypes` option.

• TS2304: Cannot find name 'satisfies'.

  cause Your project's TypeScript version is older than 4.9, and the generator's `enumType = "object"` configuration uses the `satisfies` keyword.
  fix Upgrade your TypeScript dependency to version 4.9 or higher, or change the `enumType` option in your generator configuration to a different value.

• Type 'Uint8Array' is not assignable to type 'Buffer'.

  cause The default `bytesType` changed to `Uint8Array` in v2.0.0 for Prisma v6 compatibility, but your Prisma client (likely v5) expects `Buffer`.
  fix Explicitly set `bytesType = "Buffer"` in your `generator typescriptInterfaces` block in `schema.prisma` if you are using Prisma v5.

Warnings

• breaking The `omitRelations` and `optionalRelations` options were removed and replaced by a single `relations` option. Users must migrate their configurations.
  Fix: Update your `generator` block in `schema.prisma`. Replace `omitRelations = true` or `optionalRelations = true` with `relations = "none"` or `relations = "optional"` respectively. Use `relations = "required"` for the default behavior.
• breaking The built-in `BufferObject` and `ArrayObject` types for the `bytesType` option have been removed. Attempting to use these will result in configuration errors.
  Fix: To replicate the behavior of `BufferObject` or `ArrayObject`, you must now define a custom type. Refer to the 'Custom Types' documentation for guidance on how to define these via the `customTypes` option.
• breaking When `enumType` is set to `"object"`, the generated code utilizes the TypeScript `satisfies` keyword. This introduces a breaking change for projects using TypeScript versions older than 4.9.
  Fix: Upgrade your project's TypeScript version to 4.9 or newer. Alternatively, avoid using `enumType = "object"` and choose a different `enumType` setting.
• breaking The default type for `Bytes` fields changed from `Buffer` to `Uint8Array` to align with Prisma v6's default behavior. This is a breaking change for projects on Prisma v5 expecting `Buffer` types.
  Fix: If you are using Prisma v5 and require `Buffer` types for compatibility with your Prisma client, explicitly set `bytesType = "Buffer"` in your generator configuration in `schema.prisma`.

Install

• npm install prisma-generator-typescript-interfaces npm
• yarn add prisma-generator-typescript-interfaces yarn
• pnpm add prisma-generator-typescript-interfaces pnpm

Imports

• Person
  wrong:

  const Person = require('../src/dto/interfaces');

  correct:

  import { Person } from '../src/dto/interfaces';

  Imports are for the *generated* TypeScript file, not the generator package itself. Path is relative to your source.
• Gender
  wrong:

  import Gender from '../src/dto/interfaces';

  correct:

  import { Gender } from '../src/dto/interfaces';

  Enums are generated as named exports. Ensure `exportEnums` is not `false` in your config.
• PersonJson

  import { PersonJson } from '../src/dto/json-interfaces';

  This example assumes a second generator instance configured with `output` and `modelSuffix` options.

Quickstart

This quickstart demonstrates how to configure the generator in `schema.prisma`, run the generation command, and then import and use the generated `User` interface and `Gender` enum in a TypeScript application.

/* prisma/schema.prisma */
datasource db {
  provider = "postgresql"
  url      = env("DATABASE_URL")
}

generator client {
  provider = "prisma-client-js"
}

generator typescriptInterfaces {
  provider = "prisma-generator-typescript-interfaces"
  output   = "../src/types/interfaces.ts"
  prettier = true
}

enum Gender {
  Male
  Female
  Other
}

model User {
  id        Int      @id @default(autoincrement())
  email     String   @unique
  name      String?
  age       Int
  gender    Gender
  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt
}

// Then, from your terminal:
// npm install --save-dev prisma-generator-typescript-interfaces prisma typescript
// npx prisma generate

// --- Example Usage in a TypeScript file (e.g., src/app.ts) ---

import { User, Gender } from './types/interfaces'; // Path relative to the output

const newUser: User = {
  id: 1,
  email: 'test@example.com',
  name: 'John Doe',
  age: 30,
  gender: Gender.Male,
  createdAt: new Date(),
  updatedAt: new Date()
};

function processUser(user: User) {
  console.log(`Processing user: ${user.name || user.email}, Age: ${user.age}`);
  if (user.gender === Gender.Female) {
    console.log('User is female.');
  }
}

processUser(newUser);