NestJS Singular Mapper

[BeyondBelief96]

Hello, I had a quick question about how to use a singular mapper in NestJS. I was looking at the docs and couldn't find the answer.

I have my AppModule registering a single mapper like so:

and I have my mapping profile like so:

I want to use the mapper in the OpportunityModule. I have injected the mapper into my OpportunityService like so:

But I get dependency errors saying that it can't resolve the mapper. My OpportunityModule looks like this:

What am I missing here? How do I get the mapper that's initialized at the AppModule level to resolve at the sub module level? For reference, here is the specific error I am recieving:

[Nest] 81886 - 02/28/2022, 12:06:57 PM ERROR [ExceptionHandler] Nest can't resolve dependencies of the OpportunityService (OpportunityRepository, ?). Please make sure that the argument automapper:nestjs:dto-mapper at index [1] is available in the OpportunityModule context.

Potential solutions:

• If automapper:nestjs:dto-mapper is a provider, is it part of the current OpportunityModule?
• If automapper:nestjs:dto-mapper is exported from a separate @module, is that module imported within OpportunityModule?
  @module({
  imports: [ /* the Module containing automapper:nestjs:dto-mapper */ ]
  })

[nartc]

Use @InjectMapper() without the argument.

[BeyondBelief96]

Wow, thanks for that. I saw that it was "optional" in the docs and assumed that wouldn't cause an issue.

[nartc]

Let me clarify. The context here is that you can (technically) have many different Mappers in one application. So when you provide the options with AutomapperModule.forRoot(), you provide it as an Array. And the name is the identifier of the Mapper. So you might have:

@InjectMapper('classes-mapper') private classMapper: Mapper,
@InjectMapper('pojos-mapper') private pojosMapper: Mapper

More than often though, you only have one Mapper in one application. singular:true will change the behavior of @InjectMapper()