prisma-json-types-generator

⚒️ Prisma Json Types Generator

A generator that changes the Prisma Client output to strongly type Json fields

// schema.prisma

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

/// >>> ALWAYS PUT AFTER THE PRISMA CLIENT GENERATOR <<<
generator test {
  provider = "prisma-json-types-generator"
  // namespace = "PrismaJson"
  // clientOutput = ".prisma/client" // (./ -> relative to schema, or an importable path to require() it)
}

model Test {
  /// [NormalType]
  field Json

  /// [OptionalType]
  field2 Json

  /// [ArrayType]
  field3 Json
}

// index.ts

declare global {
  namespace PrismaJson {
    type NormalType = boolean;

    type OptionalType = { a: number } | null;

    type ArrayType = { a: number }[];

    // you can use classes, interfaces, types, etc.
  }
}

// myFile.ts

import { Test } from '@prisma/client';

const test: Test = {
  // Intellisense works!
};

How it works

It works by using the typescript compiler api to interpret all emitted type declarations and changes their field type in the original file.

⚠️ It just changes the declaration files of your generated client, no runtime code is affected!

Some types are still json!

There's some complex json types like JsonFilter and JsonWithAggregatesFilter that still aren't supported. Feel free to make a PR!

https://github.com/arthurfiorette/prisma-json-types-generator/blob/9b2ceea0a8372629d224287a5590dbce1f0ca6dd/src/handler/module.ts#L92-L98

Limitations

• This project is a temporary workaround (and possible solution) to https://github.com/prisma/prisma/issues/3219.
• Json types inside type declarations won't work. (see https://github.com/prisma/prisma/issues/13726)