exception in Jest tests: `TypeError: Cannot read property 'module' of undefined` when using `forwardRef` in module `imports`

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

When creating a testing module using Test#createTestingModule method and importing a Module that has a circular dependency with another module(s) implemented using forwardRef, test fails with the following exception:

TypeError: Cannot read property 'module' of undefined

See the screen and the full exception text with a call stack in this gist

However the code itself compiles and works correctly. (see the screen)

Expected behavior

Tests should work

Minimal reproduction of the problem with instructions

Here is the repo of the example project. Just run yarn test:single to reproduce.

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

Can’t test the code containing the circular dependency.

Environment

Nest version: 4.6.6
 
For Tooling issues:
- Node version: 9.4.0
- Platform:  Mac

Others:

[kamilmysliwiec]

v5.0.0-beta.4 is using rxjs v.6.0.0 now

[kamilmysliwiec]

@alexandr2110pro keep in mind that Nest is not compatible with rxjs 6 yet (release took place yesterday)

Thanks for reporting, I’ll verify.