Return array object from resolver in nest js graphql Apollo play ground

I need to return array of objects in the nest js graphql resolver. I have a mongodb schema which have multiple object array in the schema.

@Schema()
@ObjectType()
export class Ingredient{
  @Field(() => ID)
  _id: string;

  @Prop()
  @Field({})
  ingredient_name: string;

  @Prop({type: mongoose.Types.Array})
  suppliers: [IngredientSupplier]
}

Supplier field is an object array which keep the relationship with Supplier schema with supplier_id.

@Schema()
export class IngredientSupplier {
  @Field(() => ID)
  _id: string;

  @Prop({ type: mongoose.Schema.Types.ObjectId, ref: 'Supplier' })
  @Field()
  supplier_id: string;

  @Prop({ required: true })
  @Field({})
  supplier_name: string

  @Prop({ nullable: true, default:0 })
  @Field({})
  unit_size: number;

  @Prop({ nullable: true, default: "" } )
  @Field({})
  unit_type:  string;
}

I created (mutation) ingredient records successfully in my mongodb.

{
  _id: new ObjectId("640746a5959b153fd91be321"),
  ingredient_name: 'test ingredient',
  suppliers: [
    {
      supplier_id: new ObjectId("63f8618d7f193739fac93d51"),
      supplier_name: 'test',
      unit_size: 112,
      unit_type: 'KG',
      _id: new ObjectId("640746a5959b153fd91be322")
    },
    {
      supplier_id: new ObjectId("63f880447f193739fac93d5d"),
      supplier_name: 'test11',
      unit_size: 114,
      unit_type: 'KG',
      _id: new ObjectId("640746a5959b153fd91be323")
    }
  ],

But when I am querying this record. My apollo server playground not allowing me to get the suppliers. I and successfully run the query to import *** ingredient_name**** and *** _id ****. My return type is ResultIngredientDto.

@ObjectType()
export class ResultIngredientDto {

    @Field(()=>ID)
    _id: string

    @Field()
    ingredient_name: string

    suppliers: suppliers[]
}

@ObjectType()
export class suppliers {
    @Field(()=>ID)
    _id: string

    @Field()
    supplier_id: string

    @Field({})
    supplier_name: string

    @Field()
    unit_size: number

    @Field({})
    unit_type: string

}

My graphql play ground only show

type ResultIngredientDto {
  _id: ID!
  ingredient_name: String!
}

Can some one advice me what is the change I have to do to get the supplier object array. I have printed my query output it printing all the details. Thank you in advance.

suppliers property also needs @Field decorator so you can add

@Field(() => [suppliers])