ManifestStaticFilesStorage with source maps, and ignoring missing files

storage.py

from django.contrib.staticfiles.storage import ManifestStaticFilesStorage


class ManifestStaticFilesStorageWithSourceMaps(ManifestStaticFilesStorage):
    """
    Adds js and css source map support for ManifestStaticFilesStorage.
    """

    patterns = (
        ("*.css", (
            # django uses only the first two patterns by default:
            r"""(url\(['"]{0,1}\s*(.*?)["']{0,1}\))""",
            (r"""(@import\s*["']\s*(.*?)["'])""", """@import url("%s")"""),
            (r"""(/\*#\s*sourceMappingURL=(.*)\s*\*/)""", """/*# sourceMappingURL=%s */"""),
        )),
        ("*.js", (
            (r"""(//#\s*sourceMappingURL=(.*)$)""", """//# sourceMappingURL=%s"""),
        )),
        # .js.map files can contain filenames too that might have to be hashed as well:
        # ("*.js.map", (
        #     (r"""([^/]+/static/dist/js/([^"]*))""", """%s""")
        # )),
    )

    def __init__(self, *args, **kwargs):
        self.missing_files = []
        super().__init__(*args, **kwargs)

    def hashed_name(self, name, *args, **kwargs):
        """
        Ignore missing files, e.g. non-existent background image referenced from css.
        Returns the original filename if the referenced file doesn't exist.
        """
        try:
            return super().hashed_name(name, *args, **kwargs)
        except ValueError as e:
            message = e.args[0].split(' with ')[0]
            self.missing_files.append(message)
            print(f'\x1b[0;30;41m{message}\x1b[0m')
            return name

    def post_process(self, *args, **kwargs):
        yield from super().post_process(*args, **kwargs)
        for message in sorted(set(self.missing_files)):
            print(f'\x1b[0;30;41m{message}\x1b[0m')