Nest: Request scope providers not instantiated by createTestingModule

Created on 29 Apr 2019 · 8Comments · Source: nestjs/nest

I'm submitting a...


[ ] Regression 
[x ] Bug report
[ ] Feature request
[ ] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead post your question on Stack Overflow.

Current behavior

REQUEST scope providers are not instantiated by Test.createTestingModule(...).compile()

Expected behavior

I'm not sure if this is a bug, or if REQUEST scoped providers should be tested differently.

Minimal reproduction of the problem with instructions

import { Injectable, Scope } from '@nestjs/common'
import { Test } from '@nestjs/testing'

@Injectable({
    scope: Scope.REQUEST,
})
class RequestService {
    public value: string

    constructor() {
        this.value = 'value'
    }
}

describe('Testing module', () => {
    let service: RequestService

    beforeEach(async () => {
        const module = await Test.createTestingModule({
            providers: [RequestService],
        }).compile()
        service = module.get<RequestService>(RequestService)
    })

    it('instantiates request scoped providers', () => {
        expect(service.value).toBeDefined()
    })
})

What is the motivation / use case for changing the behavior?

To be able to unit test REQUEST scope providers.

Environment


Nest version: 6.1.1


For Tooling issues:
- Node version: 10.14.2  
- Platform:  Mac 

Others:

core type

Source

meweltman

👀3

Most helpful comment

I have found one workaround, which is to force my providers to static scope in the test:

const module = await Test.createTestingModule({
    providers: [{ provide: RequestService, useClass: RequestService }],
}).compile()

meweltman on 29 Apr 2019

👍3 🎉1

All 8 comments

I have found one workaround, which is to force my providers to static scope in the test:

const module = await Test.createTestingModule({
    providers: [{ provide: RequestService, useClass: RequestService }],
}).compile()

meweltman on 29 Apr 2019

👍3 🎉1

I'm having a similar issue with my transient provider. I'm sharing my findings that may help devs fix this issue. Thi bug isn't related only to the testing mechanism. I have confirmed that if you use:

const app = await NestFactory.create(AppModule);
const service = app.get(SomeTransientProvider);

Any providers that are injected in SomeTransientProvider constructor are undefined.

Now if you create another normal provider which injects SomeTransientProvider, using this works:

const service = app.get(NormalProviderThatInjectsTransientProvider);

Here all injections work correctly.

murat-mehmet on 1 May 2019

Let's track this here: https://github.com/nestjs/nest/issues/2049

kamilmysliwiec on 13 May 2019

@meweltman Life saver, been looking for this issue for a while - i couldn't figure it out.

Your workaround is this best solution at this point then, i assume ?

iangregsondev on 29 May 2019

@appsolutegeek as far as I can tell, yes

meweltman on 31 May 2019

Dear @meweltman ,

thank you for this issue and your solution. How can you do this, if you want to test a DynamicModule?
For example, my test module init part looks like this:

beforeAll(async () => {
    const module = await Test.createTestingModule({
      imports: [
        MyDynamicModule.forRoot({
          // ... configuration params here
        }),
      ],
    }).compile();

    myDynamicService = module.get<MyService>(MyService);
  });

The MyService is a regular @Injectable() service (i.e., it has the regular Scope.SINGLETON), however, this service has another MyRequestService injected, which is Scope.REQUEST as it needs to access values from the Request itself (i.e., behave different based on values of the request).

Through the Injection Scope Hierarchy, the MyService should (automatically) be also Scope.REQUEST) because it relies on a REQUEST service.

All my tests pass until i add the MyRequestService to the constructor of the MyService - then it fails because the this.myRequestService is undefined (i.e., it cannot be created).

All the best and thanks a lot for your help