Cannot find any-observable

I ran into the issue as mentioned in the title and as it is documented here. I was able to fix it as the documentation suggested, however it is

1. suboptimal, because it requires to move the shared library code into every application library
2. also really weird to me. I don’t understand what the underlying issue is, ie how the shared library code causes the error.

Note: The PR that fixed it for me is here - specifically deleting the faast.useCase.ts file that exports a FaastUseCase class that abstracts faast implementation for downstream code.

[acchou]

BTW you can now add credentials to faastAws as part of AwsOptions, see #527.

[acchou]

Basically the issue is that faast cannot be used in the remote module because faast cannot pack itself up. In theory it’s possible you might want to invoke a lambda function from within a lambda function, but for now that cannot be done by importing faast into the remote module. Most likely, that’s not what you were trying to do in the first place…

The documentation refers to a case where the remote module and local code both imported a common file, which contained a utility function that used FaastError imported from faast itself. In this case, the utility function was only used on the local side (in the remote code, there’s no point in checking for a timeout, it’s just reported as an error to the caller). But when a faast is called on the remote code, it uses webpack to package the code for execution on lambda. When webpack runs, it finds all the dependencies of the remote code, including faast itself, through the importing of FaastError. When webpack tries to pack up faast, it fails because some of the dependencies of faast are not statically determined (for example, webpack itself. So you might say that “faast cannot be used on itself because it depends on webpack, and webpack cannot webpack itself”).

The solution was simple: just move the utility function that used FaastError into a non-shared file that was only imported on the local side, not the remote module. There’s no point in trying to see timeout errors on the remote side, after all. It was just a spurious dependency.

If you could share a little about how you’re using faast.js, I’d be happy to give some pointers.