NestJS · Senior · Question 10 of 75

Why might an injected value be `undefined` inside a constructor but defined later, with circular dependencies?

1Constructors run after onModuleInit
2Nest injects lazily by default for all providers
✓Correct answer: With forwardRef, one side may be created before the other is ready; access it after init (e.g. in onModuleInit), not in the constructor

Explanation

Avoid doing work in constructors that depends on other providers' state.

Further reading

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