Config option to define Node.js build directory

[bram-l]

- Do you want to request a feature or report a bug?
Feature

- What is the current behavior?
When Node.js functions are built with source maps enabled the hash of the ZIP file will be different each time because the name of the temporary build folder is included in the source map.

In our deployment pipeline we are using Terraform with the source_code_hash argument to detect code changes, but this is now different for each deployment regardless of any change being made.

- What is the expected behavior?
Being able to supply a build directory, similar to the rustTargetDirectory would resolve this issue.

- Please mention your node.js, and operating system version.
Node.js v14

[bram-l]

I just came across this PR evanw/esbuild#1234

@eduardoboucas is it correct that this would also fix the issue? Ideally the source map uses paths relative to the source root instead of using the temporary build directory as absolute path

[eduardoboucas]

Hi @bram-l! Thanks for raising this and apologies for the slow response.

The esbuild PR you linked would indeed solve this issue, and I think it'd be the best course of action. We can integrate it into Netlify's fork of esbuild.

I'm afraid I don't have an exact timeline for this, but I'll make sure to keep this issue updated with any progress.