ES6 Javascript functions are not working with esbuild

Hi,

I converted a few functions to use the es6 syntax. They run fine with “netlify dev” locally but when deployed they throw an error:

{"errorType":"Runtime.UserCodeSyntaxError","errorMessage":"SyntaxError: Unexpected token 'export'","trace":["Runtime.UserCodeSyntaxError: SyntaxError: Unexpected token 'export'","    at _loadUserApp (/var/runtime/UserFunction.js:98:13)","    at Object.module.exports.load (/var/runtime/UserFunction.js:140:17)","    at Object.<anonymous> (/var/runtime/index.js:43:30)","    at Module._compile (internal/modules/cjs/loader.js:999:30)","    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1027:10)","    at Module.load (internal/modules/cjs/loader.js:863:32)","    at Function.Module._load (internal/modules/cjs/loader.js:708:14)","    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:60:12)","    at internal/main/run_main_module.js:17:47"]}

Here is the function that fails:

export const handler = async (event, _context) => {
  const subject = event.queryStringParameters.name || 'World';

  try {
    return {
      statusCode: 200,
      body: JSON.stringify({
        message: `Hello ${subject}`
      })
    };
  } catch (error) {
    return { statusCode: 500, body: error.toString() };
  }
};

In my netlify.toml file I do specify esbuild:

[functions]
  directory = "functions"
  node_bundler = "esbuild"

I also have a Typescript function and it runs just fine both locally and deployed.

CJS Version (works) - https://scottwalter.netlify.app/.netlify/functions/hello-world?name=Scott Typescript Version (works) - https://scottwalter.netlify.app/.netlify/functions/hello-typescript?type=hotdog ES Version (does not work) - https://scottwalter.netlify.app/.netlify/functions/hello-world-es?name=Scott

[eduardoboucas]

Thanks, @scottfwalter. That additional context was super helpful in pointing us to the right direction. It seems to be a problem with the plugin you mentioned.

@ehmicky from our team has raised an issue in the plugin’s repo. We can keep this one open until there’s a resolution.

[eduardoboucas]

Closing as this is an issue with a plugin, not zip-it-and-ship-it.