No need to consider license-files when handling PEP 621 metadata for setuptools plugin (#34)

Previously, ini2toml was considering that project.license and project.dynamic were relevant for setting the License-file in PKG-INFO. As clarified in a recent discussion, that is not the case: setuptools can fill License-file even when project.license is static and pyproject.toml' license.file is completely unrelated to setup.cfg' license_files.

Author: abravalheri

CHANGELOG.rst

@@ -2,6 +2,14 @@
 Changelog
 =========
 
+Version 0.10
+============
+
+* ``setuptools`` plugin:
+   * Separate the handling of ``license-files`` and PEP 621 metadata, #34
+   * ``license`` and ``license-files`` are no longer added to ``tool.setuptools.dynamic``.
+      Instead ``license-files`` is added directly to ``tool.setuptools``, and the ``license`` should be added as ``project.license.text``.
+
 Version 0.9
 ===========
 

docs/setuptools_pep621.rst

@@ -30,7 +30,7 @@ proposed by ``ini2toml`` takes the following assumptions:
 - ``[options.*]`` sections in ``setup.cfg`` are translated to sub-tables of
   ``[tool.setuptools]`` in ``pyproject.toml``. For example::
 
-    [options.package_data] => [tool.setuptools.package_data]
+    [options.package_data] => [tool.setuptools.package-data]
 
 - Field and subtables in ``[tool.setuptools]`` have the ``_`` character
   replaced by ``-`` in their keys, to follow the conventions set in :pep:`517`
@@ -41,10 +41,10 @@ proposed by ``ini2toml`` takes the following assumptions:
 
     'file: description.rst' => {file = "description.rst"}
 
-  Notice, however, that these directives are not allowed to be used directly
+  Note, however, that these directives are not allowed to be used directly
   under the ``project`` table. Instead, ``ini2toml`` will rely on ``dynamic``,
   as explained bellow.
-  Also note that for some fields (e.g. ``readme`` or ``license``), ``ini2toml``
+  Also note that for some fields (e.g. ``readme``), ``ini2toml``
   might try to automatically convert the directive into values accepted by
   :pep:`621` (for complex scenarios ``dynamic`` might still be used).
 
@@ -120,8 +120,18 @@ proposed by ``ini2toml`` takes the following assumptions:
   :pypi:`setuptools` maintainers decide so. This eventual change is mentioned
   by some members of the community as a nice quality of life improvement.
 
+- The ``metadata.license_files`` field in ``setup.cfg`` is not translated to
+  ``project.license.file`` in ``pyproject.toml``, even when a single file is
+  given.  The reason behind this choice is that ``project.license.file`` is
+  meant to be used in a different way than ``metadata.license_files`` when
+  generating `core metadata`_ (the first is read and expanded into the
+  ``License`` core metadata field, the second is added as a path - relative to
+  the project root - as the ``License-file`` core metadata field). This might
+  change in the future if :pep:`639` is accepted.  Meanwhile,
+  ``metadata.license_files`` is translated to ``tool.setuptools.license-files``.
 
-Please notice these conventions are part of a proposal and will probably
+
+Please note these conventions are part of a proposal and will probably
 change as soon as a pattern is established by the :pypi:`setuptools` project.
 The implementation in ``ini2toml`` is flexible to quickly adapt to these
 changes.
@@ -130,3 +140,4 @@ changes.
 .. _TOML: https://toml.io/en/
 .. _setuptools own configuration file: https://setuptools.pypa.io/en/latest/userguide/declarative_config.html
 .. _entry-points file: https://packaging.python.org/en/latest/specifications/entry-points/
+.. _core metadata: https://packaging.python.org/en/latest/specifications/core-metadata/

setup.cfg

@@ -81,7 +81,7 @@ testing =
     tomli
     pytest
     pytest-cov
-    validate-pyproject>=0.3.2,<2
+    validate-pyproject>=0.6,<2
 
 typechecking =
     typing-extensions; python_version<"3.8"

src/ini2toml/drivers/full_toml.py

@@ -105,7 +105,7 @@ def _collapse_commented_kv(
     len_key = len(_key)
     _as_dict = obj.as_dict()
 
-    comments = list(obj._all_comments())
+    comments = list(obj._iter_comments())
     len_comments = sum(len(c) for c in comments) + 4
     # ^-- extra 4 for `  # `
 
@@ -217,6 +217,9 @@ def _convert_irepr_to_toml(irepr: IntermediateRepr, out: T) -> T:
                 ):
                     child = out.setdefault(parent_key, inline_table())
                     child[nested_key] = collapsed_value
+                    cmt = list(getattr(value, "_iter_comments", lambda: [])())
+                    if cmt:
+                        child.comment(" ".join(cmt))
                     continue
             else:
                 nested_key = tuple(rest)

src/ini2toml/intermediate_repr.py

@@ -217,6 +217,10 @@ def as_commented_list(self) -> "CommentedList[T]":
     def __repr__(self):
         return f"{self.__class__.__name__}({self.value!r}, {self.comment!r})"
 
+    def _iter_comments(self) -> Iterable[str]:
+        if self.comment:
+            yield self.comment
+
 
 class CommentedList(Generic[T], UserList):
     def __init__(self, data: Sequence[Commented[List[T]]] = ()):
@@ -235,6 +239,9 @@ def insert_line(self, i, values: Iterable[T], comment: Optional[str] = None):
         if values or comment:
             self.insert(i, Commented(values, comment))
 
+    def _iter_comments(self: Iterable[Commented]) -> Iterable[str]:
+        return chain.from_iterable(entry._iter_comments() for entry in self)
+
 
 class CommentedKV(Generic[T], UserList):
     def __init__(self, data: Sequence[Commented[List[KV[T]]]] = ()):
@@ -261,10 +268,7 @@ def as_dict(self) -> dict:
                 out[k] = v
         return out
 
-    def _all_comments(self) -> Iterable[str]:
-        for entry in self:
-            if entry.has_comment():
-                yield entry.comment
+    _iter_comments = CommentedList._iter_comments
 
     def to_ir(self) -> IntermediateRepr:
         """:class:`CommentedKV` are usually intended to represent INI options, while

src/ini2toml/plugins/setuptools_pep621.py

@@ -3,20 +3,7 @@
 import warnings
 from functools import partial, reduce
 from itertools import chain, zip_longest
-from typing import (
-    Any,
-    Dict,
-    List,
-    Mapping,
-    Optional,
-    Sequence,
-    Set,
-    Tuple,
-    Type,
-    TypeVar,
-    Union,
-    cast,
-)
+from typing import Any, Dict, List, Mapping, Sequence, Set, Tuple, Type, TypeVar, Union
 
 try:
     from packaging.requirements import Requirement
@@ -86,8 +73,6 @@
     "bdist_wheel",
     *getattr(distutils_commands, "__all__", []),
 )
-DEFAULT_LICENSE_FILES = ("LICEN[CS]E*", "COPYING*", "NOTICE*", "AUTHORS*")
-# defaults from the `wheel` package
 
 
 def activate(translator: Translator):
@@ -152,8 +137,8 @@ def processing_rules(self) -> ProcessingRules:
             #            `merge_and_rename_long_description_and_content_type`
             # ---
             ("metadata", "license-files"): split_list_comma,
-            # => NOTICE: in PEP 621, it should be a single file
-            #            further processed via `handle_license_and_files`
+            # => NOTICE: not standard for now, needs PEP 639
+            #            further processed via `remove_metadata_not_in_pep621`
             # ---
             ("metadata", "url"): split_url,
             ("metadata", "download-url"): split_url,
@@ -341,50 +326,20 @@ def merge_and_rename_long_description_and_content_type(self, doc: R) -> R:
         metadata.rename("long-description", "readme")
         return doc
 
-    def handle_license_and_files(self, doc: R) -> R:
-        """In :pep:`621` we have a single field for license, which might have a single
-        value (file path) or a dict-like structure::
-
-            license-files => license.file
-            license => license.text
+    def handle_license(self, doc: R) -> R:
+        """In :pep:`621` we have a single field for license, which is not compatible
+        with setuptools ``license-files``.
+        This field is meant to fill the ``License`` core metadata as a plain license
+        text (not a path to a file). Even when the ``project.license.file`` table field
+        is given, the idea is that the file should be expanded into text.
 
-        We also have to be aware that :pep:`621` accepts a single file, so the option of
-        combining multiple files as presented in ``setup.cfg`` have to be handled via
-        ``dynamic``.
+        This will likely change once :pep:`639` is accepted.
+        Meanwhile we have to translate ``license-files`` into a setuptools specific
+        configuration.
         """
         metadata: IR = doc["metadata"]
-        files: Optional[CommentedList[str]] = metadata.get("license-files")
-        # Setuptools automatically includes license files if not present
-        # so let's make it dynamic
-        files_as_list = (files and files.as_list()) or list(DEFAULT_LICENSE_FILES)
-        text = metadata.get("license")
-
-        # PEP 621 specifies a single "file". If there is more, we need to use "dynamic"
-        if files_as_list and (
-            len(files_as_list) > 1
-            or any(char in files_as_list[0] for char in "*?[")  # glob pattern
-            or text  # PEP 621 forbids both license and license-files at the same time
-        ):
-            metadata.setdefault("dynamic", []).append("license")
-            dynamic = doc.setdefault("options.dynamic", IR())
-            if text:
-                dynamic.append("license", text)
-            dynamic.append("license-files", files_as_list)
-            # 'file' and 'text' are mutually exclusive in PEP 621
-            metadata.pop("license", None)
-            metadata.pop("license-files", None)
-            return doc
-
-        if files_as_list:
-            files = cast(CommentedList[str], files)
-            license = IR(file=Commented(files_as_list[0], files[0].comment))
-        elif text:
-            license = IR(text=metadata["license"])
-        else:
-            return doc
-
-        fields = ("license-files", "license")
-        metadata.replace_first_remove_others(fields, "license", license)
+        if "license" in metadata:
+            metadata.rename("license", ("license", "text"))
         return doc
 
     def move_and_split_entrypoints(self, doc: R) -> R:
@@ -438,9 +393,14 @@ def remove_metadata_not_in_pep621(self, doc: R) -> R:
         """:pep:`621` does not cover all project metadata in ``setup.cfg "metadata"``
         section. That is left as "tool" specific configuration.
         """
-        specific = ["platforms", "provides", "obsoletes"]
-        metadata, options = doc["metadata"], doc["options"]
-        options.update({k: metadata.pop(k) for k in specific if k in metadata})
+        # TODO: PEP 621 does not specify an equivalent for 'License-file' metadata,
+        #       but once PEP 639 is approved this will change
+        metadata = doc.get("metadata", IR())
+        non_standard = ("platforms", "provides", "obsoletes", "license-files")
+        specific = [k for k in non_standard if k in metadata]
+        if specific:
+            options = doc.setdefault("options", IR())
+            options.update({k: metadata.pop(k) for k in specific})
         return doc
 
     def rename_script_files(self, doc: R) -> R:
@@ -665,7 +625,7 @@ def pep621_transform(self, doc: R) -> R:
             self.merge_and_rename_urls,
             self.merge_authors_maintainers_and_emails,
             self.merge_and_rename_long_description_and_content_type,
-            self.handle_license_and_files,
+            self.handle_license,
             self.move_and_split_entrypoints,
             self.move_options_missing_in_pep621,
             self.remove_metadata_not_in_pep621,

tests/examples/django/pyproject.toml

@@ -7,6 +7,7 @@ name = "Django"
 authors = [{name = "Django Software Foundation", email = "[email protected]"}]
 description = "A high-level Python web framework that encourages rapid development and clean, pragmatic design."
 readme = "README.rst"
+license = {text = "BSD-3-Clause"}
 classifiers = [
     "Development Status :: 2 - Pre-Alpha",
     "Environment :: Web Environment",
@@ -25,14 +26,14 @@ classifiers = [
     "Topic :: Software Development :: Libraries :: Application Frameworks",
     "Topic :: Software Development :: Libraries :: Python Modules",
 ]
-dynamic = ["license", "version"]
 requires-python = ">=3.8"
 dependencies = [
     "asgiref >= 3.3.2",
     'backports.zoneinfo; python_version<"3.9"',
     "sqlparse >= 0.2.2",
     "tzdata; sys_platform == 'win32'",
 ]
+dynamic = ["version"]
 
 [project.urls]
 Homepage = "https://www.djangoproject.com/"
@@ -57,8 +58,6 @@ zip-safe = false
 find = {namespaces = false}
 
 [tool.setuptools.dynamic]
-license = "BSD-3-Clause"
-license-files = ["LICEN[CS]E*", "COPYING*", "NOTICE*", "AUTHORS*"]
 version = {attr = "django.__version__"}
 
 [tool.distutils.bdist_rpm]

tests/examples/flask/pyproject.toml

@@ -4,6 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "Flask"
+license = {text = "BSD-3-Clause"}
 authors = [{name = "Armin Ronacher", email = "[email protected]"}]
 maintainers = [{name = "Pallets", email = "[email protected]"}]
 description = "A simple framework for building complex web applications."
@@ -20,8 +21,8 @@ classifiers = [
     "Topic :: Internet :: WWW/HTTP :: WSGI :: Application",
     "Topic :: Software Development :: Libraries :: Application Frameworks",
 ]
-dynamic = ["license", "version"]
 requires-python = ">= 3.6"
+dynamic = ["version"]
 
 [project.urls]
 Homepage = "https://palletsprojects.com/p/flask"
@@ -50,8 +51,6 @@ where = ["src"]
 namespaces = false
 
 [tool.setuptools.dynamic]
-license = "BSD-3-Clause"
-license-files = ["LICEN[CS]E*", "COPYING*", "NOTICE*", "AUTHORS*"]
 version = {attr = "flask.__version__"}
 
 [tool.pytest.ini_options]

tests/examples/pandas/pyproject.toml

@@ -6,6 +6,7 @@ build-backend = "setuptools.build_meta"
 name = "pandas"
 description = "Powerful data structures for data analysis, time series, and statistics"
 authors = [{name = "The Pandas Development Team", email = "[email protected]"}]
+license = {text = "BSD-3-Clause"}
 classifiers = [
     "Development Status :: 5 - Production/Stable",
     "Environment :: Console",
@@ -20,13 +21,13 @@ classifiers = [
     "Programming Language :: Python :: 3.9",
     "Topic :: Scientific/Engineering",
 ]
-dynamic = ["license", "version"]
 requires-python = ">=3.8"
 dependencies = [
     "numpy>=1.18.5",
     "python-dateutil>=2.8.1",
     "pytz>=2020.1",
 ]
+dynamic = ["version"]
 
 [project.readme]
 file = "README.md"
@@ -52,6 +53,7 @@ test = [
 include-package-data = true
 zip-safe = false
 platforms = ["any"]
+license-files = ["LICENSE"]
 
 [tool.setuptools.package-data]
 "*" = ["templates/*", "_libs/**/*.dll"]
@@ -63,10 +65,6 @@ include = ["pandas", "pandas.*"]
 # resulting files.
 namespaces = false
 
-[tool.setuptools.dynamic]
-license = "BSD-3-Clause"
-license-files = ["LICENSE"]
-
 [tool.distutils.build_ext]
 inplace = true
 

tests/examples/pluggy/pyproject.toml

@@ -8,6 +8,7 @@ build-backend = "setuptools.build_meta"
 [project]
 name = "pluggy"
 description = "plugin and hook calling mechanisms for python"
+license = {text = "MIT"}
 authors = [{name = "Holger Krekel", email = "[email protected]"}]
 classifiers = [
     "Development Status :: 6 - Mature",
@@ -30,9 +31,9 @@ classifiers = [
     "Programming Language :: Python :: 3.10",
 ]
 urls = {Homepage = "https://github.com/pytest-dev/pluggy"}
-dynamic = ["license", "version"]
 requires-python = ">=3.6"
 dependencies = ['importlib-metadata>=0.12;python_version<"3.8"']
+dynamic = ["version"]
 
 [project.readme]
 file = "README.rst"
@@ -54,9 +55,5 @@ package-dir = {"" = "src"}
 platforms = ["unix", "linux", "osx", "win32"]
 include-package-data = false
 
-[tool.setuptools.dynamic]
-license = "MIT"
-license-files = ["LICEN[CS]E*", "COPYING*", "NOTICE*", "AUTHORS*"]
-
 [tool.devpi.upload]
 formats = "sdist.tgz,bdist_wheel"