Discussion: some genelar thoughts and bundling

[hrgdavor]

I started a small personal project to play with provisioning VPS or some VMs using JS for shell scripting instead of bash,
many things I do leave as bash command as it looks ok, but I really love using JS when complex things are needed.

For start I am using Bun, as it does have a lot included, I am just bit annoyed it is 100MB binary. I still love using it, but I am on lookout for thinner JS runtime. I was looking to creating something like yavascript with quickjs as basis, but luckily bumped into this project, and I see a lot of effort has been done and it has a lot of stuff covered.

I even use bun build to generate binary for certain scripts so I can distribute it more easily. This use case would benefit a lot from size difference yavascript provides.

This project in a way already does the bundling, so I am interested in trying to making custom builds, but it would be much more easy if done by providing a binary that can be repackaged.

... just some thought, anyway thanks for building this. Hope I can make nice use of it in the future.

[suchipi]

EDIT: I had forgotten, but there's a simpler way to do this; see next comment.

There are actually already some affordances that could help you make custom builds. yavascript is built using a feature of my quickjs fork called "qjsbootstrap", where instead of having to cross-compile C binaries to build yavascript, you append JS code to the end of an already-compiled binary from QuickJS, and the modified binary executes the appended code when it's run.

In order to allow others to make custom yavascript binaries using this method, yavascript creates a side bundle called "primordials" for this purpose- it registers all the globals and other APIs yavascript uses, but doesn't contain any of the code in it specific to the yavascript CLI, like the file runner or the repl. So, to make a custom build, you would:

• Clone the yavascript repo and run its build to generate dist/bundles/primordials-arm64.js and dist/bundles/primordials-x86_64.js
  • The only difference between these two is the value of yavascript.arch.
• Get the same version of QuickJS that yavascript uses from npm. At time of writing, this is @suchipi/quickjs 0.15.0.
• Append your own code (whatever you like) to the end of (a copy of) the primordials bundle.
• Append your modified primordials bundle to the end of (a copy of) the qjsbootstrap binaries (in node_modules/@suchipi/quickjs/build/*/bin/), for each platform you want to support.

If you want slightly smaller binaries with a faster startup time, you can use qjsbootstrap-bytecode instead of the normal qjsbootstrap. Just be aware qjsbootstrap-bytecode doesn't work on windows. To do this:

• Convert your modified primordials bundle to QuickJS bytecode by running node_modules/@suchipi/quickjs/build/*/bin/file-to-bytecode.js with node_modules/@suchipi/quickjs/build/*/bin/quickjs-run.
• Append your modified primordials bundle's bytecode to the end of the qjsbootstrap-bytecode binaries (in node_modules/@suchipi/quickjs/build/*/bin/) for each platform you want to support.

yavascript's official binaries use qjsbootstrap-bytecode for all platforms except windows. For windows, the normal, non-bytecode qjsbootstrap is used.

[suchipi]

Wait, I forgot- there is a yavascript-bootstrap binary distributed with yavascript that simplifies all of this. Just append your JS code to the end of yavascript-bootstrap and it turns into a program that runs your code :)

[hrgdavor]

yavascript's official binaries use qjsbootstrap-bytecode for all platforms except windows. For windows, the normal, non-bytecode qjsbootstrap is used.

I do not care much about windows (I am still on windows but have been preparing all I need to switch to linux) ... I am just curious why there is not bytecode version for windows.

[suchipi]

It doesn't work and I haven't figured out why yet. I had a theory but it didn't end up being what I thought it was. If you're interested in debugging why, I would be super appreciative!