Add SEA support to pkg

[robertsLando]

Hi everyone, I'm a maintainer of pkg, I would like to know if someone could help/guide me adding SEA support to it. I have read docs about SEA but I'm not sure about how it could work together with pkg.

Actually what pkg does is (more info here):

• traverses the source code of an application and its dependencies looking for things like require()
• converts all the js files in v8 snapshots
• downloads a patched nodejs executable that will be used to create the application. Patches are needed to patch Node.js executable with a proxy around fs. This proxy adds the ability to look into something called a snapshot file system, which is where your project is stored. Patches are handled by pkg-fetch. It is used to create and download patched nodejs executables based on the target os/arch and node version.
• creates a snapshot filesystem
• patches fs module in order to serve file from the snapshot file system
• creates the final executable

In order to handle native addons, it simply copy them into a temporary folder on startup and the patched fs will return the temporary path when them are required in code.

I think this already covers some limitation of SEA as actually it's missing all the things related to the snapshot file system and it's actually working with a single file. Anyway the hardest part of pkg is to maintain the patched nodejs executables, that's the reason why the project is almost unmaintained right now and all maintainers give up at some point.

If we could find a way to use the features of SEA in pkg without the need of creating custom patched nodejs executable it would be awesome!

[GabenGar]

In order to avoid hacking and patching NodeJS runtime you have to implement Virtual File System first. I don't think there is a support for it by NodeJS as of now, but only because there is no reference implementation either.

[guymguym]

@roberto-slopez no, we haven't actually tried bpgk, I just thought the approach is interesting as it embeds native addons as if it was statically compiled into the executable.

[JoCat]

@roberto-slopez I've been researching this topic (using SEA to create an executable) all day today and I finally managed to connect an external module (in this case webview) only thanks to bpkg

[roberto-slopez]

@JoCat Oh, that sounds great, could you give me an example of how you did it?

[JoCat]

@roberto-slopez Yes, I'll have an example repository ready in half an hour.

[JoCat]

@roberto-slopez https://github.com/AuroraTeam/Glacier/tree/dev
Run npm i and npm run test, this will create the application