Bug: Bundling with esbuild (format ESM) fails with version >=2.28

[grimmbraten]

Expected Behavior

It works as before (version 2.27).

Current Behavior

Compiled code with esbuild (format ESM) throws an error.

Code snippet

Reproducible repository available here: https://github.com/grimmbraten/powertools-logger-esm-support.

Steps to Reproduce

Follow the instructions in the reproducible repository.

Possible Solution

No response

Powertools for AWS Lambda (TypeScript) version

latest

AWS Lambda function runtime

20.x

Packaging format used

npm

Execution logs

[svozza]

Hi there, I'm investigating this now and will update you shortly.

[svozza]

So this looks like the issue is that the InvokeStore dependency we added in #4658, is packaged as a CJS module and because it uses a Node API (node:async_hooks), this causes problems for ESBuild when it tries to bundle to ESM.

We will do a release today to revert this change but as a quick workaround if you need to be unblocked you can ask ESBuild not to bundle your Node.js dependencies by changing your build command to use the --package flag:

esbuild main.js --bundle --format=esm --platform=node --packages=external --outfile=dist/main.js

[grimmbraten]

@svozza thank you! I will await the release of the revert ☺️

[svozza]

No worries, I will ping you as soon as it's done.

[svozza]

So I've been digging into this the past while. This looks like it's a known issue with esbuild and building ESM bundles that contain CJS only modules that use require . The workaround that is proposed is that you have to use the banner option to polyfill require.

In TS:

const buildOptions: BuildOptions = {
  ...common,
  format: "esm",
  target: "esnext",
  platform: "node",
  banner: 'import { createRequire } from 'module';const require = createRequire(import.meta.url);',
  bundle,
};

esbuild(buildOptions);

Or the command line:

esbuild main.js --bundle --format=esm --platform=node --banner:js="import { createRequire } from 'module';const require = createRequire(import.meta.url);" --outfile=dist/main.js

In fact, if you look at some of our end to end tests, they use this functionality:

powertools-lambda-typescript/packages/testing/src/resources/TestNodejsFunction.ts

Line 49 in 6c65c24

? `import { createRequire } from 'module';const require = createRequire(import.meta.url);`

However, we are still going to revert this change as we don't want to require users to have to configure ESBuild when previously they didn't have to.

[powertools-for-aws-oss-automation]

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