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"
  binaryTargets = ["windows", "native"]
}

/// >>> ALWAYS PUT AFTER THE PRISMA CLIENT GENERATOR <<<
generator test {
  provider = "prisma-json-types-generator"
  namespace = "PrismaJson" // default
  output = "./custom.d.ts" // defaults to where the prisma client is generated.
  // uses ./ to resolve from this schema path, or an importable path to resolve with require.resolve
}

model Test {
  /// @json("NormalType")
  field Json

  /// @json("OptionalType")
  field2 Json

  /// @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!

Limitations

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