1 files changed, 146 insertions, 0 deletions
diff --git a/sphinx/builders/html/_assets.py b/sphinx/builders/html/_assets.py
new file mode 100644
index 0000000..a72c500
--- /dev/null
+++ b/sphinx/builders/html/_assets.py
@@ -0,0 +1,146 @@
+from __future__ import annotations
+
+import os
+import warnings
+import zlib
+from typing import TYPE_CHECKING
+
+from sphinx.deprecation import RemovedInSphinx90Warning
+from sphinx.errors import ThemeError
+
+if TYPE_CHECKING:
+    from pathlib import Path
+
+
+class _CascadingStyleSheet:
+    filename: str | os.PathLike[str]
+    priority: int
+    attributes: dict[str, str]
+
+    def __init__(
+        self,
+        filename: str | os.PathLike[str], /, *,
+        priority: int = 500,
+        rel: str = 'stylesheet',
+        type: str = 'text/css',
+        **attributes: str,
+    ) -> None:
+        object.__setattr__(self, 'filename', filename)
+        object.__setattr__(self, 'priority', priority)
+        object.__setattr__(self, 'attributes', {'rel': rel, 'type': type, **attributes})
+
+    def __str__(self):
+        attr = ', '.join(f'{k}={v!r}' for k, v in self.attributes.items())
+        return (f'{self.__class__.__name__}({self.filename!r}, '
+                f'priority={self.priority}, '
+                f'{attr})')
+
+    def __eq__(self, other):
+        if isinstance(other, str):
+            warnings.warn('The str interface for _CascadingStyleSheet objects is deprecated. '
+                          'Use css.filename instead.', RemovedInSphinx90Warning, stacklevel=2)
+            return self.filename == other
+        if not isinstance(other, _CascadingStyleSheet):
+            return NotImplemented
+        return (self.filename == other.filename
+                and self.priority == other.priority
+                and self.attributes == other.attributes)
+
+    def __hash__(self):
+        return hash((self.filename, self.priority, *sorted(self.attributes.items())))
+
+    def __setattr__(self, key, value):
+        msg = f'{self.__class__.__name__} is immutable'
+        raise AttributeError(msg)
+
+    def __delattr__(self, key):
+        msg = f'{self.__class__.__name__} is immutable'
+        raise AttributeError(msg)
+
+    def __getattr__(self, key):
+        warnings.warn('The str interface for _CascadingStyleSheet objects is deprecated. '
+                      'Use css.filename instead.', RemovedInSphinx90Warning, stacklevel=2)
+        return getattr(os.fspath(self.filename), key)
+
+    def __getitem__(self, key):
+        warnings.warn('The str interface for _CascadingStyleSheet objects is deprecated. '
+                      'Use css.filename instead.', RemovedInSphinx90Warning, stacklevel=2)
+        return os.fspath(self.filename)[key]
+
+
+class _JavaScript:
+    filename: str | os.PathLike[str]
+    priority: int
+    attributes: dict[str, str]
+
+    def __init__(
+        self,
+        filename: str | os.PathLike[str], /, *,
+        priority: int = 500,
+        **attributes: str,
+    ) -> None:
+        object.__setattr__(self, 'filename', filename)
+        object.__setattr__(self, 'priority', priority)
+        object.__setattr__(self, 'attributes', attributes)
+
+    def __str__(self):
+        attr = ''
+        if self.attributes:
+            attr = ', ' + ', '.join(f'{k}={v!r}' for k, v in self.attributes.items())
+        return (f'{self.__class__.__name__}({self.filename!r}, '
+                f'priority={self.priority}'
+                f'{attr})')
+
+    def __eq__(self, other):
+        if isinstance(other, str):
+            warnings.warn('The str interface for _JavaScript objects is deprecated. '
+                          'Use js.filename instead.', RemovedInSphinx90Warning, stacklevel=2)
+            return self.filename == other
+        if not isinstance(other, _JavaScript):
+            return NotImplemented
+        return (self.filename == other.filename
+                and self.priority == other.priority
+                and self.attributes == other.attributes)
+
+    def __hash__(self):
+        return hash((self.filename, self.priority, *sorted(self.attributes.items())))
+
+    def __setattr__(self, key, value):
+        msg = f'{self.__class__.__name__} is immutable'
+        raise AttributeError(msg)
+
+    def __delattr__(self, key):
+        msg = f'{self.__class__.__name__} is immutable'
+        raise AttributeError(msg)
+
+    def __getattr__(self, key):
+        warnings.warn('The str interface for _JavaScript objects is deprecated. '
+                      'Use js.filename instead.', RemovedInSphinx90Warning, stacklevel=2)
+        return getattr(os.fspath(self.filename), key)
+
+    def __getitem__(self, key):
+        warnings.warn('The str interface for _JavaScript objects is deprecated. '
+                      'Use js.filename instead.', RemovedInSphinx90Warning, stacklevel=2)
+        return os.fspath(self.filename)[key]
+
+
+def _file_checksum(outdir: Path, filename: str | os.PathLike[str]) -> str:
+    filename = os.fspath(filename)
+    # Don't generate checksums for HTTP URIs
+    if '://' in filename:
+        return ''
+    # Some themes and extensions have used query strings
+    # for a similar asset checksum feature.
+    # As we cannot safely strip the query string,
+    # raise an error to the user.
+    if '?' in filename:
+        msg = f'Local asset file paths must not contain query strings: {filename!r}'
+        raise ThemeError(msg)
+    try:
+        # Remove all carriage returns to avoid checksum differences
+        content = outdir.joinpath(filename).read_bytes().translate(None, b'\r')
+    except FileNotFoundError:
+        return ''
+    if not content:
+        return ''
+    return f'{zlib.crc32(content):08x}'