Switch parser backend to tinycss2

Author: domdfcoding

dict2css/__init__.py

@@ -31,19 +31,15 @@
 
 # stdlib
 from io import TextIOBase
-from typing import IO, Any, Dict, Mapping, MutableMapping, Sequence, Union, cast
+from typing import IO, Any, Dict, Iterable, List, Mapping, MutableMapping, Sequence, Union, cast
 
 # 3rd party
+import tinycss2
+import tinycss2.ast
 from domdf_python_tools.paths import PathPlus
 from domdf_python_tools.typing import PathLike
 from domdf_python_tools.words import TAB
 
-try:
-	# 3rd party
-	import css_parser  # type: ignore
-except ImportError:  # pragma: no cover
-	import cssutils as css_parser  # type: ignore
-
 # this package
 from dict2css.helpers import em, px, rem  # noqa: F401
 from dict2css.serializer import CSSSerializer
@@ -258,44 +254,46 @@ def loads(styles: str) -> MutableMapping[str, MutableMapping[str, Any]]:
 	:return: The style sheet as a dictionary.
 	"""
 
-	parser = css_parser.CSSParser(validate=False)
-	stylesheet: css_parser.css.CSSStyleSheet = parser.parseString(styles)
+	stylesheet = tinycss2.parse_blocks_contents(styles, skip_comments=True, skip_whitespace=True)
 
 	styles_dict: MutableMapping[str, MutableMapping[str, Any]] = {}
 
-	def parse_style(style: css_parser.css.CSSStyleDeclaration) -> MutableMapping[str, Property]:
+	def parse_style(style: List[tinycss2.ast.Node]) -> MutableMapping[str, Property]:
 		style_dict: Dict[str, Property] = {}
 
-		prop: css_parser.css.Property
-		for prop in style.children():
-			if prop.priority:
-				style_dict[prop.name] = (prop.value, prop.priority)
+		prop: Union[tinycss2.ast.ParseError, tinycss2.ast.Declaration]
+		for prop in tinycss2.parse_declaration_list(style, skip_comments=True, skip_whitespace=True):
+			if isinstance(prop, tinycss2.ast.ParseError):
+				raise ValueError(prop)
+
+			if prop.important:
+				style_dict[prop.name.strip()] = (_serialize(prop.value), IMPORTANT)
 			else:
-				style_dict[prop.name] = prop.value
+				style_dict[prop.name.strip()] = _serialize(prop.value)
 
 		return style_dict
 
-	rule: css_parser.css.CSSRule
-	for rule in stylesheet.cssRules:
-		if isinstance(rule, css_parser.css.CSSStyleRule):
-			styles_dict[rule.selectorText] = parse_style(rule.style)
-
-		elif isinstance(rule, css_parser.css.CSSMediaRule):
-			styles_dict[f"@media {rule.media.mediaText}"] = {}
+	rule: tinycss2.ast.Node
+	for rule in stylesheet:
+		if isinstance(rule, tinycss2.ast.QualifiedRule):
+			styles_dict[_serialize(rule.prelude)] = parse_style(rule.content)
 
-			for child in rule.cssRules:
-				styles_dict[f"@media {rule.media.mediaText}"][child.selectorText] = parse_style(child.style)
+		elif isinstance(rule, tinycss2.ast.AtRule):
+			at_rule_styles = styles_dict[f"@{rule.at_keyword} {_serialize(rule.prelude)}"] = at_rule_styles
 
-		elif isinstance(rule, (css_parser.css.CSSComment)):  # pragma: no cover
-			# Ignore these classes
-			pass
+			for child in tinycss2.parse_blocks_contents(rule.content, skip_comments=True, skip_whitespace=True):
+				at_rule_styles[_serialize(child.prelude)] = parse_style(child.content)
 
 		else:
 			raise NotImplementedError(rule)
 
 	return styles_dict
 
 
+def _serialize(nodes: Iterable[tinycss2.ast.Node]):
+	return tinycss2.serialize(nodes).strip()
+
+
 def load(fp: Union[PathLike, IO]) -> MutableMapping[str, MutableMapping[str, Any]]:
 	r"""
 	Parse a cascading style sheet from the given file and return its dictionary representation.

dict2css/serializer.py

@@ -35,13 +35,6 @@
 # 3rd party
 from domdf_python_tools.words import TAB
 
-try:
-	# 3rd party
-	import css_parser  # type: ignore
-except ImportError:  # pragma: no cover
-	# 3rd party
-	import cssutils as css_parser  # type: ignore
-
 __all__ = ["CSSSerializer"]
 
 

doc-source/conf.py

@@ -101,6 +101,5 @@ def setup(app):
 
 nitpicky = True
 latex_elements["preamble"] = "\\raggedbottom\n\\widowpenalty10000"
-ignore_missing_xrefs = ["^css_parser\\."]
 autosummary_widths_builders = ["latex"]
 changelog_sections_numbered = False

pyproject.toml

@@ -139,9 +139,6 @@ reformat = true
 
 [tool.snippet-fmt.languages.json]
 
-[tool.dep_checker]
-allowed_unused = [ "cssutils",]
-
 [tool.dependency-dash."requirements.txt"]
 order = 10
 

repo_helper.yml

@@ -42,7 +42,6 @@ classifiers:
 sphinx_conf_epilogue:
  - nitpicky = True
  - latex_elements["preamble"] = "\\raggedbottom\n\\widowpenalty10000"
- - ignore_missing_xrefs = ["^css_parser\\."]
  - autosummary_widths_builders = ["latex"]
  - changelog_sections_numbered = False
 
@@ -57,6 +56,3 @@ extra_sphinx_extensions:
  - sphinx_toolbox_experimental.missing_xref
  - sphinx_toolbox_experimental.changelog
  - latex_mu
-
-tox_unmanaged:
- - testenv

requirements.txt

@@ -1,4 +1,2 @@
-# css-parser>=1.0.6
-# Later cssutils polluted by AI and the new licence-breaking chardet
-cssutils<=2.11.0,>=2.2.0
 domdf-python-tools>=2.2.0
+tinycss2>=1.2.1

tests/test_dict2css.py

@@ -2,7 +2,6 @@
 from typing import Dict, Mapping, MutableMapping
 
 # 3rd party
-import cssutils  # type: ignore
 import pytest
 from coincidence.regressions import AdvancedDataRegressionFixture, AdvancedFileRegressionFixture
 from domdf_python_tools.paths import PathPlus

tox.ini

@@ -225,7 +225,4 @@ setenv =
 deps = -r{toxinidir}/tests/requirements.txt
 commands =
     python --version
-    python -m pip uninstall css-parser -y
     python -m pytest --cov=dict2css -r aR tests/ {posargs}
-    python -m pip install "css-parser>=1.0.6"
-    python -m pytest --cov=dict2css -r aR tests/ --cov-append {posargs}