Feature request: Do not force --enable-source-maps output in build.

intptr-t commented 9 months ago

Describe your idea/feature/enhancement

When creating a TypeScript Lambda function, I would like to avoid forcing the "--enable-source-maps" output of the "Sourcemap: true" standard.

The purpose is to use source-map-support as a result of the following performance measurements. https://github.com/cspotcode/source-map-performance-demo

Proposal

Proposal1. make the output of "NODE_OPTIONS: '--enable-source-maps'" optional if "Sourcemap: true" is specified Proposal2. add a parameter to disable "NODE_OPTIONS: ' --enable-source-maps

Proposal1 example

This one will change the current behavior.

    Metadata:
      BuildMethod: esbuild
      BuildProperties:
        Sourcemap: true
      EnableSourceMap: true  # This one

Proposal2 example

This does not change the current default behavior of outputting "NODE_OPTIONS: '--enable-source-maps'".

    Metadata:
      BuildMethod: esbuild
      BuildProperties:
        Sourcemap: true
      DisableEnableSourcemap: true  # This one

Additional Details

We get the following options

[Current] Sourcemap: If false, *.js.map is not output and NODE_OPTIONS: ' --enable-source-maps' is not output
[Current] Sourcemap: if true, *.js.map is output and NODE_OPTIONS: ' --enable-source-maps
[This issue idea]Sourcemap: if true, *.js.map is output and NODE_OPTIONS: ' --enable-source-maps' is not output
- Once this method is added, third-party libraries (e.g., source-map-support) can be used to handle source maps.

The --enable-source-maps slow issue seems to be resolved in Node 19 from the reference link above, but the current LTS is Node 18. I think it is a good idea to address this in SAM rather than wait for Node 20 to be supported in AWS Lambda We think it is a good idea to support SAM rather than waiting for Node 20 to be supported by AWS Lambda. Also important is the option to use third party libraries.

sriram-mv commented 9 months ago

Does this have environment variable support? if that is the case you could possibly pass this option in by setting an env var in the build? Though I would need to check on how we handle env vars for this specifically.

intptr-t commented 9 months ago

@sriram-mv In terms of current(1.98.0), from what I have been able to ascertain, environment variables are not supported. Input from a template seems to be the current design.

https://github.com/aws/aws-sam-cli/blob/develop/samcli/lib/build/bundler.py#L86

But, I believe it is technically feasible to add new support for metadata output from environment variables. However, it would be very complicated with environment variables to support the case where function A automatically generates --enable-source-maps as before and function B does not.

Assumed sample of cases handled by environment variables

SAM_DISABLE_ENABLE_SOURCE_MAP__FuncA=false
SAM_DISABLE_ENABLE_SOURCE_MAP__FuncB=true
sam build template.yaml

Samples of templates only

Resources:
  #
  # FuncA automatically outputs --enable-source-maps.
  # Example case: This is because cold starts, batch processing, etc., where the speed of the Node.js runtime is not affected.
  #
  FuncA:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: assets/lambdas/funcA
      Handler: app.handler
      Runtime: nodejs18.x
      Timeout: 900
      Environment:
        Variables:
          EnvA: "VarA"
    Metadata:
      BuildMethod: esbuild
      BuildProperties:
        Format: cjs
        Minify: false
        Target: "es2022"
        Sourcemap: true
  #
  # FuncB will output sourcemap files, but not --enable-source-maps.
  # Example case: This is because it is a use case where a relatively fast response is desired.
  #
  FuncB:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: assets/lambdas/funcB
      Handler: app.handler
      Runtime: nodejs18.x
      Timeout: 1
      Environment:
        Variables:
          EnvB: "VarB"
    Metadata:
      BuildMethod: esbuild
      BuildProperties:
        Format: cjs
        Minify: false
        Target: "es2022"
        Sourcemap: true
        DisableEnableSourcemap: true  # This one

aws / aws-sam-cli