prisma: Node hangs when `console.log(new PrismaClient())`

I’m running into an issue that may be a different manifestation of this same issue. In Visual Studio Code, whenever I attempt to debug into a class that extends PrismaClient, the node process hangs. Also if I attempt to inspect the instance of this class before stepping into it, the node process hangs. I’m not able to debug any of my classes that extend PrismaClient because of this. I wonder if the debugging issue has something to do with the debugger inspecting the PrismaClient instance for a watch locals or something and this inspecting leads to the same error as logging the PrismaClient instance.

@janpio I’ve just tested and can confirm that the dev version no-longer freezes REPL instance when the command would output anything with prisma instance on it.

With 5.10.2 it does freeze, so the fix must’ve addressed it correcly.

Can’t wait for the release, thanks SevInf and team for the fix 🙌

@llimllib you can work around the issue with this:

const repl = require("node:repl");

const r = repl.start("> ");
r.context.prisma = new (require("@prisma/client").PrismaClient)();
r.context.prisma[Symbol.for('nodejs.util.inspect.custom')] = 'PrismaClient';

as suggested here: https://github.com/prisma/prisma/issues/19648#issuecomment-1680911900

It works with the dev version. Thank you !

Hey everyone that commented in this issue before, could you please try to temporarily install prisma@dev and @prisma/client@dev in your project and see if this fixes the problem? https://github.com/prisma/prisma/pull/23228 should have fixed this and will be included in the next release, but of course a confirmation of it now working as intended would be nice.

I can actually log new PrismaClient() fine:

const { PrismaClient } = require('@prisma/client')

async function main() {
    console.log(new PrismaClient())
}

main()
  .catch(async (e) => {
    console.error(e)
    await prisma.$disconnect()
    process.exit(1)
  })

When I put the output of this into a file, it is 525 MB (551.039.534 bytes) big though - so I would not be surprised if that would crash in some environments.

The output looks recursive to me in 2 places:

{
  _middlewares: MiddlewareHandler { _middlewares: [] },
  _getDmmf: [Function (anonymous)],
  _getProtocolEncoder: [Function (anonymous)],
  '$extends': [Function: $extends],
  _extensions: MergedExtensionsList { head: undefined },
  _previewFeatures: [],
  _rejectOnNotFound: undefined,
  _clientVersion: '4.13.0',
  _activeProvider: 'postgresql',
  _dataProxy: false,
  _tracingConfig: { enabled: [Getter], middleware: [Getter] },
  _clientEngineType: 'library',
  _errorFormat: 'colorless',
  _baseDmmf: {
    datamodel: { enums: [], models: [Array], types: [] },
    datamodelEnumMap: {},
    modelMap: { User: [Object] },
    typeMap: {},
    typeAndModelMap: { User: [Object] },
    mappings: { modelOperations: [Array], otherOperations: [Object] },
    mappingsMap: { User: [Object] }
  },
  _engineConfig: {
    cwd: 'C:\\Users\\Jan\\Documents\\throwaway\\18292\\prisma',
    dirname: 'C:\\Users\\Jan\\Documents\\throwaway\\18292\\node_modules\\.prisma\\client',
    enableDebugLogs: false,
    allowTriggerPanic: undefined,
    datamodelPath: 'C:\\Users\\Jan\\Documents\\throwaway\\18292\\node_modules\\.prisma\\client\\schema.prisma',
    prismaPath: undefined,
    engineEndpoint: undefined,
    datasources: [],
    generator: {
      name: 'client',
      provider: [Object],
      output: [Object],
      config: [Object],
      binaryTargets: [],
      previewFeatures: []
    },
    showColors: false,
    logLevel: undefined,
    logQueries: undefined,
    env: {
      DATABASE_URL: 'postgresql://johndoe:randompassword@localhost:5432/mydb?schema=public'
    },
    flags: [],
    clientVersion: '4.13.0',
    previewFeatures: [],
    activeProvider: 'postgresql',
    inlineSchema: undefined,
    inlineDatasources: undefined,
    inlineSchemaHash: undefined,
    tracingConfig: { enabled: [Getter], middleware: [Getter] },
    logEmitter: EventEmitter {
      _events: [Object: null prototype],
      _eventsCount: 1,
      _maxListeners: undefined,
      [Symbol(kCapture)]: false
    },
    engineProtocol: 'graphql'
  },
  _engine: LibraryEngine {
    datamodel: '// This is your Prisma schema file,\n' +
      '// learn more about it in the docs: https://pris.ly/d/prisma-schema\n' +
      '\n' +
      'generator client {\n' +
      '  provider = "prisma-client-js"\n' +
      '}\n' +
      '\n' +
      'datasource db {\n' +
      '  provider = "postgresql"\n' +
      '  url      = env("DATABASE_URL")\n' +
      '}\n' +
      '\n' +
      'model User {\n' +
      '  id    Int     @id @default(autoincrement())\n' +
      '  email String  @unique\n' +
      '  name  String?\n' +
      '}\n',
    config: {
      cwd: 'C:\\Users\\Jan\\Documents\\throwaway\\18292\\prisma',
      dirname: 'C:\\Users\\Jan\\Documents\\throwaway\\18292\\node_modules\\.prisma\\client',
      enableDebugLogs: false,
      allowTriggerPanic: undefined,
      datamodelPath: 'C:\\Users\\Jan\\Documents\\throwaway\\18292\\node_modules\\.prisma\\client\\schema.prisma',
      prismaPath: undefined,
      engineEndpoint: undefined,
      datasources: [],
      generator: [Object],
      showColors: false,
      logLevel: undefined,
      logQueries: undefined,
      env: [Object],
      flags: [],
      clientVersion: '4.13.0',
      previewFeatures: [],
      activeProvider: 'postgresql',
      inlineSchema: undefined,
      inlineDatasources: undefined,
      inlineSchemaHash: undefined,
      tracingConfig: [Object],
      logEmitter: [EventEmitter],
      engineProtocol: 'graphql'
    },
    libraryStarted: false,
    logQueries: false,
    logLevel: 'error',
    libraryLoader: DefaultLibraryLoader {
      libQueryEnginePath: null,
      platform: null,
      config: [Object]
    },
    logEmitter: EventEmitter {
      _events: [Object: null prototype],
      _eventsCount: 1,
      _maxListeners: undefined,
      [Symbol(kCapture)]: false
    },
    engineProtocol: 'graphql',
    datasourceOverrides: [Object: null prototype] {},
    libraryInstantiationPromise: Promise { <pending> }
  },
  _fetcher: RequestHandler {
    logEmitter: EventEmitter {
      _events: [Object: null prototype],
      _eventsCount: 1,
      _maxListeners: undefined,
      [Symbol(kCapture)]: false
    },
    client: {
       ... RECURSION 1 HERE ...
    },
    dataloader: DataLoader { options: [Object], tickActive: false, batches: {} }
  },
  _metrics: MetricsClient {
    _engine: LibraryEngine {
      datamodel: '// This is your Prisma schema file,\n' +
        '// learn more about it in the docs: https://pris.ly/d/prisma-schema\n' +
        '\n' +
        'generator client {\n' +
        '  provider = "prisma-client-js"\n' +
        '}\n' +
        '\n' +
        'datasource db {\n' +
        '  provider = "postgresql"\n' +
        '  url      = env("DATABASE_URL")\n' +
        '}\n' +
        '\n' +
        'model User {\n' +
        '  id    Int     @id @default(autoincrement())\n' +
        '  email String  @unique\n' +
        '  name  String?\n' +
        '}\n',
      config: [Object],
      libraryStarted: false,
      logQueries: false,
      logLevel: 'error',
      libraryLoader: [DefaultLibraryLoader],
      logEmitter: [EventEmitter],
      engineProtocol: 'graphql',
      datasourceOverrides: [Object: null prototype] {},
      libraryInstantiationPromise: [Promise]
    }
  },
  user: {
    findUnique: [Function (anonymous)],
    findUniqueOrThrow: [Function (anonymous)],
    findFirst: [Function (anonymous)],
    findFirstOrThrow: [Function (anonymous)],
    findMany: [Function (anonymous)],
    create: [Function (anonymous)],
    createMany: [Function (anonymous)],
    delete: [Function (anonymous)],
    update: [Function (anonymous)],
    deleteMany: [Function (anonymous)],
    updateMany: [Function (anonymous)],
    upsert: [Function (anonymous)],
    aggregate: [Function (anonymous)],
    groupBy: [Function (anonymous)],
    count: [Function (anonymous)],
    name: 'User'
  },
  [Symbol()]: {
      ... RECURSION 2 HERE ...
   }
}

Both cases are roughly 100.000 lines long in my file.

Not optimal.

This issue prevents me from using prisma in the node REPL; I don’t literally want to log the output of the client, but I do want to use it in a repl.

Here’s a node REPL script that reproduces the issue:

const repl = require("node:repl");

const r = repl.start("> ");
r.context.prisma = new (require("@prisma/client").PrismaClient)();

run that script, type pri, node tries to autocomplete prisma and the process immediately hangs; it’s not even responsive to ctrl+c interrupt at that point.

Hello, there is an expression in Spanish that says: “Donde dije digo y donde digo Diego”, basically a way of saying that I was wrong. Yesterday after some more time testing I discovered that the problem only occurs when creating a console.log(“prismaclient instance”). So my apologies, and I encourage you to keep working as you have been doing with this great tool. Regards

It’s art 🤣

This is the behaviour that I see on 4.7.0; warning if you’re sensitive to flashing imagery. Not sure that this is necessarily working as intended, but it doesn’t hang at least

https://github.com/prisma/prisma/assets/29753584/bb02a165-bb98-42b9-a54d-fd39545aeecd