Sam build duplicates dependency packages even if they share the same manifest about aws-sam-cli

[kalpaitch]

I'll address those two suggestions separately:

1. a) Changing the directory structure is a far from ideal solution in our use case. b) Nor do I feel caching the dependencies should be related to the CodeUri, I'm referring to the .aws-sam/deps/ directory, which only contains npm dependencies, not the .aws-sam/build/ or /.aws-sam/cache directories. c) many of these lambdas are in the same directory, and with the CodeUri specified it's still building to different .aws-sam/deps/ directories, see the manifest hash and CodeUri below are all the same but the dependency folder is different:

Manifest file is changed (new hash: ea718884c53ee6b0028d7c088f8fefeb) or dependency folder (.aws-sam/deps/70501117-f47d-4d63-84e2-1ed000911263) is missing for (Lambda1Function)                                                                                     
Building codeuri: backend/api/src/handlers/subfolder1
Manifest file is changed (new hash: ea718884c53ee6b0028d7c088f8fefeb) or dependency folder (.aws-sam/deps/5af21d52-0418-420a-82bd-775da3082ff6) is missing for (Lambda2Function)                                                                           
Building codeuri: backend/api/src/handlers/subfolder1
Manifest file is changed (new hash: ea718884c53ee6b0028d7c088f8fefeb) or dependency folder (.aws-sam/deps/1c6738a0-e3f2-4f74-9c6e-f983a96cd008) is missing for (Lambda3Function)                                                                              
Building codeuri: backend/api/src/handlers/subfolder1

2. We are using esbuild to bundle these functions which is a far better solution in this case than use a layer, so this isn't an option.

In short, I think there probably is still an issue here, either documentation related or build related.

[lucashuy]

Hi, the build dependencies are cached based on the manifest file (the package.json file), and the value of the CodeUri for each of the functions. If you tried moving the handler files to the same directory (and updating the corresponding CodeUris in the template), you should see that the deps are shared. Alternatively, you can utilize a Lambda Layer to share common dependencies, instead of having a single package.json shared between Lambda Functions.