When do you inject vs. just import? (config)

[danielbrauer]

My guess is that injecting dependencies is more important when they own resources, but I'm still curious why something like config isn't injected.

[salmanahmad94]

My guess is that the configuration is supposed to be part of the runtime environment and not a dependency. For example, if all your configuration is being imported by dotenv and loaded in the src/config/app.js file, it'd be better to add src/config as a global module resolved by babel. And then in individual services, you could import config like import config from 'config';

My guess is that injecting dependencies is more important when they own resources, but I'm still curious why something like config isn't injected.

[silesky]

I don’t know if there are any hard and fast rules about this. It is a good question of “where do you draw the line”?

I think — since we are talking about global configuration of services that themselves are injected, its idiomatic for config to be an imported module.

Because node has a proper module system and imports can be stubbed about as easily as DI services, there isn’t any reason to use DI other than you prefer the semantics.

[elemanhillary]

You inject when Dependency is registered in the container and its not decorated with @service, and you imported when dependency is not registered but its decorated with @service