Unable to infer GraphQL type from TypeScript reflection system

[hmz22]

Describe the Bug
I create this model

import { getModelForClass } from "@typegoose/typegoose";
import { GraphQLObjectID } from "graphql-scalars";
import { Field, ObjectType } from "type-graphql";
import { publicConnection } from "../../startup/db";

@ObjectType()
export class Member {
  @Field(() => GraphQLObjectID)
  _id!: string;

  @Field()
  firstname?: string;

  @Field()
  lastname?: string;
}

export const MemberModel = getModelForClass(Member, {
  existingConnection: publicConnection,
  schemaOptions: {
    timestamps: true,
  },
});

and this my resolver:

import { Query, Resolver } from "type-graphql";
import { Member, MemberModel } from "./member.model";

@Resolver(() => Member)
export default class MemberResolver {
  @Query(() => [Member])
  async members() {
    return await MemberModel.find({});
  }
}

after run project show this error in console

D:\Projects\Tests\node-ts-sample-decorator2\node_modules\type-graphql\dist\helpers\findType.js:19
        throw new errors_1.NoExplicitTypeError(prototype.constructor.name, propertyKey, parameterIndex, argName);
              ^
Error: Unable to infer GraphQL type from TypeScript reflection system. You need to provide explicit type for 'firstname' of 'Member' class.

when I change @Field() to @Field(type => String) this error gone but in your document no need add this

• OS: Windows 11
• Node 14.18.3
• Package version [1.2.0-rc.1]
• TypeScript version 4.7.4

[hmz22]

Describe the Bug I create this model

import { getModelForClass } from "@typegoose/typegoose";
import { GraphQLObjectID } from "graphql-scalars";
import { Field, ObjectType } from "type-graphql";
import { publicConnection } from "../../startup/db";

@ObjectType()
export class Member {
  @Field(() => GraphQLObjectID)
  _id!: string;

  @Field()
  firstname?: string;

  @Field()
  lastname?: string;
}

export const MemberModel = getModelForClass(Member, {
  existingConnection: publicConnection,
  schemaOptions: {
    timestamps: true,
  },
});

and this my resolver:

import { Query, Resolver } from "type-graphql";
import { Member, MemberModel } from "./member.model";

@Resolver(() => Member)
export default class MemberResolver {
  @Query(() => [Member])
  async members() {
    return await MemberModel.find({});
  }
}

after run project show this error in console

D:\Projects\Tests\node-ts-sample-decorator2\node_modules\type-graphql\dist\helpers\findType.js:19
        throw new errors_1.NoExplicitTypeError(prototype.constructor.name, propertyKey, parameterIndex, argName);
              ^
Error: Unable to infer GraphQL type from TypeScript reflection system. You need to provide explicit type for 'firstname' of 'Member' class.

when I change @Field() to @Field(type => String) this error gone but in your document no need add this

• OS: Windows 11
• Node 14.18.3
• Package version [1.2.0-rc.1]
• TypeScript version 4.7.4

I forget say I use esbuild for run this program

[MichalLytek]

That's the root cause. See #55

[samrith-s]

@MichalLytek I couldn't gather much from the really long discussion in that issue. Any leads on how to solve it for esbuild?

[hmz22]

I install @anatine/esbuild-decorators and solved my problem because esbuild not support decorator.

[samrith-s]

I tried it with the plugin, still same issue. This is my esbuild.config.js:

/* eslint-disable @typescript-eslint/no-var-requires */
const { esbuildDecorators } = require('@anatine/esbuild-decorators');

module.exports = () => ({
  packager: 'yarn',
  packagerOptions: {
    scripts: [
      'rm -rf node_modules',
      'cp ../../prisma/schema.prisma src/schema.prisma',
    ],
  },
  keepOutputDirectory: true,
  external: [
    'cache-manager',
    '@nestjs/websockets',
    '@nestjs/microservices',
    'superagent-proxy',
    'apollo-server-fastify',
    'class-transformer',
    '@apollo/federation',
    'fsevents',
  ],
  plugins: [esbuildDecorators()],
});

[samrith-s]

My bad! I was running the wrong command. I needed to invoke the local function, not the errored one which has been deployed:

- sls invoke -f main
+ sis invoke local -f main

[jingjiezhou2021]

For anyone who already configured

{
  "emitDecoratorMetadata": true,
  "experimentalDecorators": true
}

in tsconfig.json but still run into NoExplicitTypeError, you might be using tsx which doesn't support emitDecoratorMetadata: tsx compiler limitations