Dynamic modules in NestJS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a dynamic module in NestJS?

A dynamic module is a module that can be configured and created at runtime with custom providers, imports, and exports. It allows flexibility to pass parameters and create reusable modules.

intermediate

How do you define a dynamic module in NestJS?

You define a dynamic module by creating a static method (usually called forRoot or forFeature) that returns a DynamicModule object with metadata like providers, imports, and exports based on passed options.

beginner

Why use dynamic modules instead of static modules?

Dynamic modules let you customize module behavior and dependencies at runtime, making your code more flexible and reusable for different configurations or environments.

intermediate

What is the typical signature of a dynamic module factory method?

It is a static method that accepts options as parameters and returns an object with the shape: { module: YourModule, providers: [...], exports: [...], imports?: [...] }.

beginner

Can dynamic modules import other modules in NestJS?

Yes, dynamic modules can import other modules dynamically by including them in the imports array of the returned module metadata.

What does a dynamic module factory method usually return?

A A string with module name

B A plain JavaScript object without module info

C A function that runs on app start

D An object with module metadata including providers and exports

A dynamic module factory method returns an object describing the module, including providers, imports, and exports.

Which keyword is used to define a dynamic module factory method in NestJS?

A static

B async

C private

D export

The factory method is defined as a static method so it can be called without creating an instance.

Why might you use a dynamic module in NestJS?

A To write less code by skipping imports

B To avoid using modules altogether

C To configure module providers based on runtime options

D To make modules static and fixed

Dynamic modules allow configuration of providers and imports based on options passed at runtime.

Which of these is NOT part of a dynamic module's returned object?

A components

B module

C exports

D providers

The returned object includes module, providers, imports, and exports, but not components.

Can dynamic modules be reused with different configurations?

A Only if you use global modules

B Yes, by passing different options to the factory method

C Only if you restart the app

D No, they are fixed once created

Dynamic modules are designed to be reusable with different configurations by passing options.

Explain how to create a dynamic module in NestJS and why it is useful.

Think about how you can pass options to customize a module.

Describe the structure of the object returned by a dynamic module's factory method.

What does NestJS expect to know about the module?