Mapping doesn't await child using AfterMappingAsync (Async package)

[Bjorn-Anamatch]

When mapping objects using the Async package:

        await _mapper.From(result).AdaptToTypeAsync<ParentDto>();

We see that the mapping is not complete when the result is already returned.

        config.NewConfig<Parent, ParentDto>()
            .Map(dest => dest.ParentDetailsInternal, src => src.ParentDetails)
            .AfterMappingAsync(AfterMappingParentToDto)
            ;

        config.NewConfig<ParentDetail, ParentDetailDto>()
            .Include<ParentDetailSubType, ParentDetailSubTypeDto>()
            .AfterMappingAsync(AfterMappingChildToDto)
            ;

It seems the .Map method is not expecting async methods further down the mapping chain. The AfterMappingAsync on the child is not yet finished.

[Bjorn-Anamatch]

Found a work-around for now by adding this in the AfterMappingSync method of the parent:

    private async Task AfterMappingParentToDto(Parent source, ParentDto target)
    {
        // Wait for previous tasks to end to make sure all child mappings have finished.
        var tasks = (List<Task>)MapContext.Current?.Parameters.GetValueOrDefault("Mapster.Async.tasks");
        if(tasks != null && tasks.Any())
        {
            await Task.WhenAll(tasks);
        }

But I don't like using the static name Mapster.Async.tasks directly. (That's not public btw, thank you open source)

I'll try to create a pull request on the async package.

[andrerav]

Good catch there, looking forward to the PR. I will ensure it gets merged quickly and push a prerelease package for you.

[gdoron]

Hi, I got to this thread while try to figure out if we should migrate from automapper to mapster. Basically the biggest motivation for us it async mappers. Does \ will it exist in mapster?

Thanks!