This is an attempt to run dart-sass using QuickJS.

Steps:

Get the QuickJS command line tool. An easy way to do this is to simply download the cosmopolitan binary from the QuickJS page and unzip it: https://bellard.org/quickjs/

Then run:

qjs sass.js examples/test.scss

To compile Bootstrap 5, I needed to use a larger stack size:

qjs --stack-size 1000000 sass.js bootstrap5/bootstrap.scss > bootstrap.css

Note: There currently seems to be a bug handling comments with Bootstrap. This may be due to the workarounds that I added (see Notes section below) not being quite right.

This will compile it to a standalone binary file named sass:

qjsc -S 1000000 -o sass sass.js

Then the binary can be used like this:

./sass examples/test.scss

The following command will emit C source code which can be compiled into a standalone executable:

qjsc -S 1000000 -e -o sass.c sass.js

To compile to a binary, you will need to specify the include dir and library dir for QuickJS. These directories can typically be found by running which qjsc and searching around in the relative paths.

gcc -I /nix/store/f1sfjkih8mxyn2hh04gnz8zhkn8i79lq-quickjs-2021-03-27/include/quickjs -L /nix/store/f1sfjkih8mxyn2hh04gnz8zhkn8i79lq-quickjs-2021-03-27/lib/quickjs -lquickjs -o sass sass.c

There is a bug in QuickJS that I worked around by modifying code in sass.dart.js. Once QuickJS fixes this bug, those workarounds shouldn't be needed anymore.

The QuickJS environment is missing some common things from a browser or NodeJS runtime, like URL() and console.error. Some of those things also needed to be added explicitly to globalThis. These things are done in browser-shims.js.