Sith/staticfiles/processors.py

import logging
import subprocess
from dataclasses import dataclass
from pathlib import Path
from typing import Iterable

import rjsmin
import sass
from django.conf import settings

from staticfiles.apps import GENERATED_ROOT


class Webpack:
    @staticmethod
    def compile():
        """Bundle js files with webpack for production."""
        process = subprocess.Popen(["npm", "run", "compile"])
        process.wait()
        if process.returncode:
            raise RuntimeError(f"Webpack failed with returncode {process.returncode}")

    @staticmethod
    def runserver() -> subprocess.Popen:
        """Bundle js files automatically in background when called in debug mode."""
        logging.getLogger("django").info("Running webpack server")
        return subprocess.Popen(["npm", "run", "serve"])


class Scss:
    @dataclass
    class CompileArg:
        absolute: Path  # Absolute path to the file
        relative: Path  # Relative path inside the folder it has been collected

    @staticmethod
    def compile(files: CompileArg | Iterable[CompileArg]):
        """Compile scss files to css files."""
        # Generate files inside the generated folder
        # .css files respects the hierarchy in the static folder it was found
        # This converts arg.absolute -> generated/{arg.relative}.scss
        # Example:
        #   app/static/foo.scss          -> generated/foo.css
        #   app/static/bar/foo.scss      -> generated/bar/foo.css
        #   custom/location/bar/foo.scss -> generated/bar/foo.css
        if isinstance(files, Scss.CompileArg):
            files = [files]

        base_args = {"output_style": "compressed", "precision": settings.SASS_PRECISION}

        compiled_files = {
            file.relative.with_suffix(".css"): sass.compile(
                filename=str(file.absolute), **base_args
            )
            for file in files
        }
        for file, content in compiled_files.items():
            dest = GENERATED_ROOT / file
            dest.parent.mkdir(exist_ok=True, parents=True)
            dest.write_text(content)


class JS:
    @staticmethod
    def minify():
        to_exec = [
            p for p in settings.STATIC_ROOT.rglob("*.js") if ".min" not in p.suffixes
        ]
        for path in to_exec:
            p = path.resolve()
            minified = rjsmin.jsmin(p.read_text())
            p.write_text(minified)
            logging.getLogger("main").info(f"Minified {path}")