TypeError: Cannot convert object to primitive value

Issue type:

[ ] question [x] bug report [ ] feature request [ ] documentation issue

Database system/driver:

[ ] cordova [ ] mongodb [ ] mssql [ ] mysql / mariadb [ ] oracle [x] postgres [ ] sqlite [ ] sqljs [ ] react-native

TypeORM version:

[ ] latest [ ] @next [x] 0.2.0 (or put your version here)

Steps to reproduce or a small repository showing the problem:

I am using NestJs with Typeorm I get the request object form graphql, graphql parameters do not have __proto__ set. I am directly passing the graphql paramter object to the save method. I am getting the below error when I do that:

TypeError: Cannot convert object to primitive value
    at new MustBeEntityError (/Users/shashikiranms/projects/vcbackend/src/error/MustBeEntityError.ts:10:43)
    at EntityPersistExecutor.execute (/Users/shashikiranms/projects/vcbackend/node_modules/typeorm/persistence/EntityPersistExecutor.js:77:35)
    at EntityManager.save (/Users/shashikiranms/projects/vcbackend/src/entity-manager/EntityManager.ts:298:14)
    at UserRepository.Repository.save (/Users/shashikiranms/projects/vcbackend/src/repository/Repository.ts:138:29)

When I debugged the issue, it is beacause EntityPersistExecutor.js checks for the entity to be an instanceof Object, which is false, because __proto__ is not set for the entity

if (!this.entity || !(this.entity instanceof Object)) {
     return Promise.reject(new MustBeEntityError_1.MustBeEntityError(this.mode, this.entity));
}

I think changing the above condition this.entity instanceof Object to typeof this.entity === 'object' solves the problem

PS: It was working in version 0.1.20. It is breaking once I upgraded to 0.2.0

[amille14]

Just ran into this issue using type-graphql, typeorm and nestjs and was scratching my head for a while. This is a really obtuse issue and causes silent bugs. There are workarounds but it really needs to be fixed.

[jpoppe]

I solved it for my use case in NestJS with a simple object spread (required for input):

@Mutation(() => Item)               
public createItem(@Args('input') input: ItemCreateInput): Promise<Item>         
  return this.itemsService.create({...input}) // spread operator to clone input to new object                            
 } 

Hope it helps…