Table of Contents

• Installation
• Usage
• Customizations
• Roadmap
• Inspirations

Installation

• This package assumes you have project initialized with Prisma, Next.JS.

• Works best with a few dependencies to validate api-routes and keep code DRY

Using pnpm:

 pnpm add -D prisma-zod-generator && pnpm add next-api-middleware zod superjson

Using yarn:

 yarn add -D prisma-zod-generator && yarn add next-api-middleware zod superjson

Using npm:

 npm install -D prisma-zod-generator && npm install next-api-middleware zod superjson

Example Project

This repository contains an example project to play with.

git clone https://github.com/justinsgithub/prisma-generator-next && \
cd prisma-generator-next/usage && \
npm install && npm run gen && npm run dev

Usage

1. Add the generator to your Prisma schema

generator zod {
  provider = "prisma-zod-generator"
}

2. Enable strict mode in tsconfig as it is required by Zod, and considered a Typescript best practice

{
  "compilerOptions": {
    "strict": true
  }
}

3. Run npx prisma generate

If your prisma.schema looked like this...

model User {
  id    Int     @id @default(autoincrement())
  email String  @unique
  name  String?
  posts Post[]
}

model Post {
  id        Int      @id @default(autoincrement())
  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt
  title     String
  content   String?
  published Boolean  @default(false)
  viewCount Int      @default(0)
  author    User?    @relation(fields: [authorId], references: [id])
  authorId  Int?
  likes     BigInt
}

...it would generate the following files

4. edit the generated files as needed

WARNING: certain files should be thought of as "read-only", as they will be regenerated every time prisma generate is ran. Any changes to the "read-only" files would be lost, files clarify if they are okay to modify at the top.

import { PostCreateOneSchema } from './prisma/generated/schemas/createOnePost.schema';

app.post('/blog', async (req, res, next) => {
  const { body } = req;
  await PostCreateOneSchema.parse(body);
});

Customizations

You can add options to your prisma.schema to customize generator output

Please feel free to submit an issue if you have a good idea for any new customizations or features to be added.

Skipping entire models

/// @@Gen.model(hide: true)
model User {
  id    Int     @id @default(autoincrement())
  email String  @unique
  name  String?
}

Additional Options

• The output option is relative to the prisma.schema file, so the default ./generated would output to prisma/generated (unless you have your schema file in a custom location)

• The outputSuffix option is to try and protect against overwriting any files you already have in your project

  • example: if output = "../" and outputSuffix = "" then if you have files named db.ts and middleware.ts in the src directory, they would be overwritten!! Along with any other files you have with the same name as the generated files.

| Option | Description | Type | Default | | ------------------- | -------------------------------------------------------------------------- | --------- | ------------- | | output | Output directory for the generated files | string | ../src | | outputSuffix | Directory the files will be output to (inside the output directory) | string | pgen | | apiRoutePrefix | Namespace to avoid overwriting api-routes you already have of the same name | boolean | pgen | | prismaVarName | Incase you use a different variable name to initialize PrismaClient | string | prisma | | prismaFilePath | Path to the file where you export the prisma file | string | ../src/pgen/db.ts| | useBigInt | have Zod validate BigInt types as bigint instead of number (not recommended) | boolean | false | | isGenerateSelect | Enables the generation of Select related schemas and the select property | boolean | true | | isGenerateInclude | Enables the generation of Include related schemas and the include property | boolean | true |

Use additional options in the schema.prisma

Important

• useBigInt defaults to false because sending a BigInt value from a web client is complicated.
• I think it is perfectly fine for Zod to just validate that it is a number because Prisma will accept it just fine.
• The BigInt type is why superjson is used to serialize the Prisma data before sending Response to client.

generator next {
  provider = "prisma-generator-next"
  output   = "../src"
  outputSuffix = "pgen" // ${output}/pgen/${generatedFiles}
  apiRoutePrefix = "pgen" // pages/api/pgen/${modelName}
  prismaFilePath = "../src/pgen/db.ts"
  prismaVarName = "prisma"
  useBigInt = false
  isGenerateSelect  = true
  isGenerateInclude = true
}

Roadmap

• Turn this project into a complete Next.JS app generator, including generating a front-end client for the api routes.

• Any feedback and suggestions will be greatly appreciated.

Inspirations

Huge thanks to other generator projects that I was able to learn and take from.

Especially prisma-zod-generator, the code responsible for generating the Zod schemas for this project.

• [typegraphql-prisma] (https://github.com/MichalLytek/typegraphql-prisma)
• [prisma-trpc-generator] (https://github.com/omar-dulaimi/prisma-trpc-generator)

Also big shout out to create-prisma-generator for giving me somewhere to start from