get list of imported chunks for each entrypoint

[nitsky]

The initial load of a web app can be sped up by preloading all javascript chunks it needs using <link> tags. This could be done with the esbuild JS or Go API like it is done with Rollup, where each output chunk has imports and dynamicImports keys specifying paths to the corresponding output files. Rollup's CLI doesn't currently support outputting this information, but perhaps esbuild could optionally emit a manifest file with metadata on all emitted entrypoints, chunks, and assets.

Below is a link to the relevant Rollup docs section:

http://rollupjs.org/guide/en/#rolluprollup

[evanw]

Thanks for logging this. I agree that this would be good to do.

There actually already is a way to emit a metadata file (the --metafile flag) but it probably doesn't yet output all of the information it needs to for code splitting.

[evanw]

This information has been added to the metafile output starting in version 0.6.0. See the release notes for more information.