Add support for PEP 639 license expressions.

Author: domdfcoding

pyproject_parser/classes.py

@@ -242,6 +242,8 @@ class License:
 	.. latex:vspace:: 20px
 
 	.. autosummary-widths:: 6/16
+
+	.. versionchanged:: 0.14.0  Add ``expression`` option.
 	"""
 
 	#: The path to the license file.
@@ -250,10 +252,19 @@ class License:
 	#: The content of the license.
 	text: Optional[str] = attr.ib(default=None)
 
+	#: An SPDX License Expression (for :pep:`639`).
+	expression: Optional[str] = attr.ib(default=None)
+
 	def __attrs_post_init__(self) -> None:
 		# Sanity checks the supplied arguments
-		if self.text is None and self.file is None:
-			raise TypeError(f"At least one of 'text' and 'file' must be supplied to {self.__class__!r}")
+		if self.expression:
+			if self.text is not None or self.file is not None:
+				raise TypeError(
+						f"Cannot supply a licence expression alongside 'text' and/or 'file' to {self.__class__!r}"
+						)
+		else:
+			if self.text is None and self.file is None:
+				raise TypeError(f"At least one of 'text' and 'file' must be supplied to {self.__class__!r}")
 
 		# if self.text is not None and self.file is not None:
 		# 	raise TypeError("'text' and 'filename' are mutually exclusive.")
@@ -294,6 +305,8 @@ def to_dict(self) -> Dict[str, str]:
 			as_dict["file"] = self.file.as_posix()
 		if self.text is not None:
 			as_dict["text"] = self.text
+		if self.expression is not None:
+			as_dict["expression"] = self.expression
 
 		return as_dict
 

pyproject_parser/parsers.py

@@ -36,6 +36,7 @@
 from typing import Any, Callable, ClassVar, Dict, Iterable, List, Mapping, Set, Union, cast
 
 # 3rd party
+import license_expression  # type: ignore[import]
 from apeye_core import URL
 from apeye_core.email_validator import EmailSyntaxError, validate_email
 from dom_toml.parser import TOML_TYPES, AbstractConfigParser, BadConfigError, construct_path
@@ -50,7 +51,12 @@
 # this package
 from pyproject_parser.classes import License, Readme, _NormalisedName
 from pyproject_parser.type_hints import Author, BuildSystemDict, DependencyGroupsDict, ProjectDict
-from pyproject_parser.utils import PyProjectDeprecationWarning, content_type_from_filename, render_readme
+from pyproject_parser.utils import (
+		PyProjectDeprecationWarning,
+		content_type_from_filename,
+		indent_join,
+		render_readme
+		)
 
 __all__ = [
 		"RequiredKeysConfigParser",
@@ -599,13 +605,13 @@ def parse_requires_python(config: Dict[str, TOML_TYPES]) -> SpecifierSet:
 			raise
 
 	@staticmethod
-	@_documentation_url("https://whey.readthedocs.io/en/latest/configuration.html#tconf-project.license")
+	@_documentation_url("https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license")
 	def parse_license(config: Dict[str, TOML_TYPES]) -> License:
 		"""
 		Parse the :pep621:`license` key.
 
-		* **Format**: :toml:`Table`
-		* **Core Metadata**: :core-meta:`License`
+		* **Format**: :toml:`Table` or :toml:`String`
+		* **Core Metadata**: :core-meta:`License` or :core-meta:`License-Expression`
 
 		The table may have one of two keys:
 
@@ -615,6 +621,9 @@ def parse_license(config: Dict[str, TOML_TYPES]) -> License:
 
 		These keys are mutually exclusive,  so a tool MUST raise an error if the metadata specifies both keys.
 
+		Alternatively, for :pep:`639` support, the value may be a string giving an
+		`SPDX License Expression <https://packaging.python.org/en/latest/glossary/#term-License-Expression>`_.
+
 		:bold-title:`Example:`
 
 		.. code-block:: TOML
@@ -631,11 +640,31 @@ def parse_license(config: Dict[str, TOML_TYPES]) -> License:
 			and then the user promises not to redistribute it.
 			\"\"\"
 
+			[project]
+			license = "MIT AND (Apache-2.0 OR BSD-2-Clause)"
+
 		:param config: The unparsed TOML config for the :pep621:`project table <table-name>`.
 		"""  # noqa: D300,D301
 
 		project_license = config["license"]
 
+		if isinstance(project_license, str):
+			# PEP 639
+			if project_license.startswith("LicenseRef-"):
+				return License(expression=project_license)
+			else:
+				licensing = license_expression.get_spdx_licensing()
+				validated_spdx = licensing.validate(project_license)
+				if validated_spdx.errors:
+					# validated_spdx.errors.append("Another Error")
+					warning_msg = "'project.license-key' is not a valid SPDX Expression: "
+					warning_msg += indent_join(validated_spdx.errors)
+					raise BadConfigError(warning_msg)
+				else:
+					# TODO: normalise, maybe from validated_spdx object
+					return License(expression=project_license)
+
+		# Traditional PEP 621
 		if "text" in project_license and "file" in project_license:
 			raise BadConfigError(
 					"The 'project.license.file' and 'project.license.text' keys "

pyproject_parser/utils.py

@@ -31,7 +31,8 @@
 import io
 import os
 import sys
-from typing import TYPE_CHECKING, Any, Dict, Optional
+import textwrap
+from typing import TYPE_CHECKING, Any, Callable, Dict, Iterable, Optional
 
 # 3rd party
 import dom_toml
@@ -43,7 +44,14 @@
 	# this package
 	from pyproject_parser.type_hints import ContentTypes
 
-__all__ = ["render_markdown", "render_rst", "content_type_from_filename", "PyProjectDeprecationWarning"]
+__all__ = [
+		"render_markdown",
+		"render_rst",
+		"content_type_from_filename",
+		"PyProjectDeprecationWarning",
+		"indent_join",
+		"indent_with_tab"
+		]
 
 
 def render_markdown(content: str) -> None:
@@ -187,3 +195,44 @@ def _load_toml(filename: PathLike, ) -> Dict[str, Any]:
 	"""
 
 	return dom_toml.load(filename)
+
+
+def indent_join(iterable: Iterable[str]) -> str:
+	"""
+	Join an iterable of strings with newlines, and indent each line with a tab if there is more then one element.
+
+	:param iterable:
+
+	:rtype:
+
+	.. versionadded:: 0.14.0
+	"""
+
+	iterable = list(iterable)
+	if len(iterable) > 1:
+		if not iterable[0] == '':
+			iterable.insert(0, '')
+
+	return indent_with_tab(textwrap.dedent('\n'.join(iterable)))
+
+
+def indent_with_tab(
+		text: str,
+		depth: int = 1,
+		predicate: Optional[Callable[[str], bool]] = None,
+		) -> str:
+	r"""
+	Adds ``'\t'`` to the beginning of selected lines in 'text'.
+
+	:param text: The text to indent.
+	:param depth: The depth of the indentation.
+	:param predicate: If given, ``'\t'``  will only be added to the lines where ``predicate(line)``
+		is :py:obj`True`. If ``predicate`` is not provided, it will default to adding ``'\t'``
+		to all non-empty lines that do not consist solely of whitespace characters.
+
+	:rtype:
+
+	.. versionadded:: 0.14.0
+	"""
+
+	return textwrap.indent(text, '\t' * depth, predicate=predicate)

requirements.txt

@@ -2,6 +2,7 @@ apeye-core>=1.0.0
 attrs>=20.3.0
 dom-toml>=2.0.0
 domdf-python-tools>=2.8.0
+license-expression>=30.0.0
 natsort>=7.1.1
 packaging>=20.9
 shippinglabel>=1.0.0

tests/test_config.py

@@ -33,6 +33,12 @@
 		[
 				*valid_pep621_config,
 				pytest.param(f"{OPTIONAL_DEPENDENCIES}dev-test = ['black']\n", id="optional-dependencies-hyphen"),
+				pytest.param(f"{MINIMAL_CONFIG}\nlicense = 'GPL-3.0-or-later'\n", id="pep639-gpl"),
+				pytest.param(
+						f"{MINIMAL_CONFIG}\nlicense = 'MIT AND (Apache-2.0 OR BSD-2-Clause)'\n",
+						id="pep639-and-or",
+						),
+				pytest.param(f"{MINIMAL_CONFIG}\nlicense = 'LicenseRef-My-Custom-License'\n", id="pep639-custom"),
 				]
 		)
 def test_pep621_class_valid_config(
@@ -57,7 +63,18 @@ class ReducedPEP621Parser(PEP621Parser, inherit_defaults=True):
 	keys = ["name", "version", "dependencies"]
 
 
-@pytest.mark.parametrize("toml_config", valid_pep621_config)
+@pytest.mark.parametrize(
+		"toml_config",
+		[
+				*valid_pep621_config,
+				pytest.param(f"{MINIMAL_CONFIG}\nlicense = 'GPL-3.0-or-later'\n", id="pep639-gpl"),
+				pytest.param(
+						f"{MINIMAL_CONFIG}\nlicense = 'MIT AND (Apache-2.0 OR BSD-2-Clause)'\n",
+						id="pep639-and-or",
+						),
+				pytest.param(f"{MINIMAL_CONFIG}\nlicense = 'LicenseRef-My-Custom-License'\n", id="pep639-custom"),
+				]
+		)
 def test_pep621_subclass(
 		toml_config: str,
 		tmp_pathplus: PathPlus,
@@ -387,6 +404,24 @@ def test_pep621_class_bad_config_license(
 						"Invalid extra name 'number#1'",
 						id="extra_invalid_c",
 						),
+				pytest.param(
+						f"{MINIMAL_CONFIG}\nlicense = 'GPL-4.0'\n",
+						BadConfigError,
+						r"'project.license-key' is not a valid SPDX Expression: \tUnknown license key\(s\): GPL-4.0",
+						id="pep639-gpl4",
+						),
+				pytest.param(
+						f"{MINIMAL_CONFIG}\nlicense = 'MIX an (Apache-2.0'\n",
+						BadConfigError,
+						r"'project.license-key' is not a valid SPDX Expression: \tInvalid expression nesting such as \(AND xx\) for token: \"\(\" at position: 7",
+						id="pep639-mangled",
+						),
+				pytest.param(
+						f"{MINIMAL_CONFIG}\nlicense = 'My-Custom-License'\n",
+						BadConfigError,
+						r"'project.license-key' is not a valid SPDX Expression: \tUnknown license key\(s\): My-Custom-License",
+						id="pep639-custom",
+						),
 				]
 		)
 def test_pep621_class_bad_config(

tests/test_config_/test_pep621_class_valid_config_pep639_and_or_False_.yml

@@ -0,0 +1,5 @@
+dynamic: []
+license:
+  expression: MIT AND (Apache-2.0 OR BSD-2-Clause)
+name: spam
+version: 2020.0.0

tests/test_config_/test_pep621_class_valid_config_pep639_and_or_True_.yml

@@ -0,0 +1,18 @@
+authors: []
+classifiers: []
+dependencies: []
+description: null
+dynamic: []
+entry-points: {}
+gui-scripts: {}
+keywords: []
+license:
+  expression: MIT AND (Apache-2.0 OR BSD-2-Clause)
+maintainers: []
+name: spam
+optional-dependencies: {}
+readme: null
+requires-python: null
+scripts: {}
+urls: {}
+version: 2020.0.0

tests/test_config_/test_pep621_class_valid_config_pep639_custom_False_.yml

@@ -0,0 +1,5 @@
+dynamic: []
+license:
+  expression: LicenseRef-My-Custom-License
+name: spam
+version: 2020.0.0

tests/test_config_/test_pep621_class_valid_config_pep639_custom_True_.yml

@@ -0,0 +1,18 @@
+authors: []
+classifiers: []
+dependencies: []
+description: null
+dynamic: []
+entry-points: {}
+gui-scripts: {}
+keywords: []
+license:
+  expression: LicenseRef-My-Custom-License
+maintainers: []
+name: spam
+optional-dependencies: {}
+readme: null
+requires-python: null
+scripts: {}
+urls: {}
+version: 2020.0.0

tests/test_config_/test_pep621_class_valid_config_pep639_gpl_False_.yml

@@ -0,0 +1,5 @@
+dynamic: []
+license:
+  expression: GPL-3.0-or-later
+name: spam
+version: 2020.0.0