AWS lambda esm builds

[emcfarlane]

Thanks for the project! 🙏 The "type": "module" isn't passed down to package.json on built functions. AWS lambda thinks the module is a commonJS module and fails to parse.

Another option tried is editing the esbuild ext:

      "esbuildConfigOverride": {
        "format": "esm",
        "target": "node18",
        "outExtension": {
          ".js": ".mjs"
        }
      },

[emcfarlane]

Just saw this example: https://github.com/doteric/funpack/blob/master/examples/mjs-extension/package.json 👍

[doteric]

Hey @emcfarlane, yes, exactly, you can override all the configuration options of esbuild using the funpack configuration. I would like to also add presets for specific setups, but no ETA's yet so you have to override the esbuild config.

You can also use the "type": "module" from the package.json, here is an example: https://github.com/doteric/funpack/blob/master/examples/module-splitting/package.json#L12
This configuration will also pass the type inside your package.json to the package.json in the output/bundle. packageFieldsToCopy is responsible for this to be exact.

Let me know if this answers your questions. If you have any other problems or ideas feel free to let me know.

[emcfarlane]

Thanks!