Unnecessary Helpers?

[evanplaice]

I'm using ESBuild to bundle ESM -> ESM bundle and it includes the following

let __defineProperty = Object.defineProperty;
let __markAsModule = (target) => {
  return __defineProperty(target, "__esModule", {value: true});
};
let __export = (target, all) => {
  __markAsModule(target);
  for (let name in all)
    __defineProperty(target, name, {get: all[name], enumerable: true});
};

AFAIK, pure ESM -> ESM transform shouldn't require anything additional to work. Is this unnecessary bloat?

I'm using the following settings

esbuild --format=esm --bundle src/wc-blink.js --outfile=index2.js

[evanw]

Thanks for calling this out. I had also noticed this recently and it's been on my list of things to fix, but I might as well fix it now.

This is a result of cross-contamination between dependencies for ES6 namespace exports and ES6 entry point exports. ES6 namespace exports (the ns object from import * as ns from 'path') are always generated for every file but are removed by tree shaking if they are unused. The same code that generates ES6 namespace exports also generates the exports for entry points when using the esm format because the two tasks are very similar. They were accidentally sharing the same dependency list instead of maintaining two separate dependency lists.

I'll get this fixed soon.

[evanplaice]

Awesome! I just started using ESBuild so I wasn't sure if this was necessary or extra. I'll keep an eye out for the fix.

BTW, great job on ESBuild 👍. Bundling is shockingly fast. I can't wait to update all of my projects to use it.