NestJS · Senior · Question 4 of 75

A REQUEST-scoped provider is injected into a singleton service. What happens?

✓Correct answer: The service and its consumers become request-scoped too, so the whole chain is instantiated per request
2Nest throws an error at startup
3The singleton gets the first request's instance forever

Explanation

Scope bubbles up. In a busy app this can multiply allocations per request; durable providers or ALS are alternatives for multi-tenancy.

Further reading

NestJS: Injection scopes ↗

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