support package.json type script

[wenerme]

esbuild bundle systemjs

The "type" field must be set to either "commonjs" or "module".

xref systemjs/systemjs#2420

[evanw]

The type field must be set to either commonjs or module for npm packages: https://nodejs.org/api/packages.html#type. The value script is not one of the valid values for that field. In addition, both esbuild and node only support those two module formats as input.

Edit: That said this is a warning, not an error, so you should still be able to build the package and have it do something. Warnings do not stop a build. Invalid values for the type field are just ignored by esbuild. You are welcome to silence warnings about invalid package.json files with --log-override:package.json=silent if you don't want to see them.

[sapphi-red]

esbuild seems to load a file as JSON when sourcemap: true is set.

Here's the reproduction: https://stackblitz.com/edit/esbuild-template-3mtzn8?file=build.js

[sapphi-red]

No, it wasn't. systemjs's file was incorrect.

system.min.js includes the following code...

//# sourceMappingURL=system.min.js

related: systemjs/systemjs#2421

[guybedford]

@evanw JSPM supports a "type": "script" field to enable distinguishing scripts from modules in ESM CDN workflows, which turned out to be important when ESM is being optimized under different constraints (scripts and modules minify differently). I don't expect it to be supported elsewhere anytime soon, and a warning is no problem though.

[evanw]

Ok. This is still not a module format that either node or esbuild supports, so I think the warning is ok. And with the investigation above about the JSON parsing problems (thanks for investigating this) it sounds like esbuild isn't doing anything wrong here. So I'm going to close this issue.