Flatten the value of the license-files key, only globs are specified

Author: befeleme

peps/pep-0639.rst

@@ -520,87 +520,61 @@ paths in the project source tree relative to ``pyproject.toml`` to file(s)
 containing licenses and other legal notices to be distributed with the package.
 It corresponds to the ``License-File`` fields in the Core Metadata.
 
-Its value is a table, which if present MUST contain one of two optional,
-mutually exclusive subkeys, ``paths`` and ``globs``; if both are specified,
-tools MUST raise an error. Both are arrays of strings; the ``paths`` subkey
-contains verbatim file paths, and the ``globs`` subkey valid glob patterns,
-which MUST be parsable by the ``glob`` `module <globmodule_>`__ in the
-Python standard library.
-
+Its value is an array of strings which MUST contain valid glob patterns,
+as specified below.
+The glob patterns MAY contain special glob characters: ``*``, ``?``, ``**``
+and character ranges: ``[]``, and tools MUST support them.
 Path delimiters MUST be the forward slash character (``/``),
 and parent directory indicators (``..``) MUST NOT be used.
 Tools MUST assume that license file content is valid UTF-8 encoded text,
 and SHOULD validate this and raise an error if it is not.
 
-If the ``paths`` subkey is a non-empty array, build tools:
-
-- MUST treat each value as a verbatim, literal file path, and
-  MUST NOT treat them as glob patterns.
-
-- MUST include each listed file in all distribution archives.
-
-- MUST NOT match any additional license files beyond those explicitly
-  statically specified by the user under the ``paths`` subkey.
+Literal paths (e.g. ``LICENSE``) are treated as valid globs which means they
+can also be defined.
 
-- MUST list each file path under a ``License-File`` field in the Core Metadata.
+To achieve better portability, the filenames to match should only contain
+the alphanumeric characters and dot (``.``).
 
-- MUST raise an error if one or more paths do not correspond to a valid file
-  in the project source that can be copied into the distribution archive.
-
-If the ``globs`` subkey is a non-empty array, build tools:
+Build tools:
 
 - MUST treat each value as a glob pattern, and MUST raise an error if the
   pattern contains invalid glob syntax.
 
-- MUST include all files matched by at least one listed pattern in all
+- MUST include all files matched by a listed pattern in all
   distribution archives.
 
-- MAY exclude files matched by glob patterns that can be unambiguously
-  determined to be backup, temporary, hidden, OS-generated or VCS-ignored.
-
 - MUST list each matched file path under a ``License-File`` field in the
   Core Metadata.
 
-- SHOULD issue a warning and MAY raise an error if no files are matched.
-
-- MAY issue a warning if any individual user-specified pattern
+- MUST raise an error if any individual user-specified pattern
   does not match at least one file.
 
-If the ``license-files`` key is present, and the ``paths`` or ``globs`` subkey
+If the ``license-files`` key is present and
 is set to a value of an empty array, then tools MUST NOT include any
 license files and MUST NOT raise an error.
 
-
 Examples of valid license files declaration:
 
 .. code-block:: toml
 
     [project]
-    license-files = { globs = ["LICEN[CS]E*", "AUTHORS*"] }
+    license-files = ["LICEN[CS]E*", "AUTHORS*"]
 
     [project]
-    license-files.paths = ["licenses/LICENSE.MIT", "licenses/LICENSE.CC0"]
+    license-files = ["licenses/LICENSE.MIT", "licenses/LICENSE.CC0"]
 
     [project]
-    license-files = { paths = [] }
+    license-files = ["LICENSE.txt", "licenses/*"]
 
     [project]
-    license-files.globs = []
+    license-files = []
 
 Examples of invalid license files declaration:
 
 .. code-block:: toml
 
     [project]
-    license-files.globs = ["LICEN[CS]E*", "AUTHORS*"]
-    license-files.paths = ["LICENSE.MIT"]
-
-Reason: license-files.paths and license-files.globs are mutually exclusive.
-
-.. code-block:: toml
-
-    [project]
-    license-files = { paths = ["..\LICENSE.MIT"] }
+    license-files = ["..\LICENSE.MIT"]
 
 Reason: ``..`` must not be used.
 ``\`` is an invalid path delimiter, ``/`` must be used.
@@ -609,7 +583,7 @@ Reason: ``..`` must not be used.
 .. code-block:: toml
 
     [project]
-    license-files = { globs = ["LICEN{CSE*"] }
+    license-files = ["LICEN{CSE*"]
 
 Reason: "LICEN{CSE*" is not a valid glob.
 
@@ -638,7 +612,7 @@ the ``license-files`` key instead.
 If the specified license ``file`` is present in the source tree,
 build tools SHOULD use it to fill the ``License-File`` field
 in the core metadata, and MUST include the specified file
-as if it were specified in a ``license-file.paths`` field.
+as if it were specified in a ``license-file`` field.
 If the file does not exist at the specified path,
 tools MUST raise an informative error as previously specified.
 
@@ -725,9 +699,9 @@ and license classifiers retain backwards compatibility. A removal is
 left to a future PEP and a new version of the Core Metadata specification.
 
 Specification of the new ``License-File`` Core Metadata field and adding the
-files in the distribution codifies the existing practices of many packaging
-tools. It is designed to be largely backwards-compatible with their existing
-use of that field. The new ``license-files`` key in the ``[project]`` table of
+files in the distribution is designed to be largely backwards-compatible with
+the existing use of that field in many packaging tools.
+The new ``license-files`` key in the ``[project]`` table of
 ``pyproject.toml`` will only have an effect once users and tools adopt it.
 
 This PEP specifies that license files should be placed in a dedicated
@@ -781,7 +755,8 @@ If an invalid ``License-Expression`` is used, the users will not be able
 to publish their package to PyPI and an error message will help them
 understand they need to use SPDX identifiers.
 It will be possible to generate a distribution with incorrect license metadata,
-but not to publish one on PyPI or any other index server that enforces ``License-Expression`` validity.
+but not to publish one on PyPI or any other index server that enforces
+``License-Expression`` validity.
 For authors using the now-deprecated ``License`` field or license classifiers,
 packaging tools may warn them and inform them of the replacement,
 ``License-Expression``.

peps/pep-0639/appendix-examples.rst

@@ -127,29 +127,30 @@ Putting it all together, our ``setup.cfg`` would be:
         setuptools/_vendor/packaging/LICENSE.APACHE
         setuptools/_vendor/packaging/LICENSE.BSD
 
-In the ``[project]`` table of ``pyproject.toml``, with license files
-specified explicitly via the ``paths`` subkey, this would look like:
+In the ``[project]`` table of ``pyproject.toml``, license files
+can be specified via glob patterns:
 
 .. code-block:: toml
 
     [project]
     license = "MIT AND (Apache-2.0 OR BSD-2-Clause)"
-    license-files.paths = [
-        "LICENSE",
-        "setuptools/_vendor/LICENSE",
-        "setuptools/_vendor/LICENSE.APACHE",
-        "setuptools/_vendor/LICENSE.BSD",
+    license-files = [
+        "LICENSE*",
+        "setuptools/_vendor/LICENSE*",
     ]
 
-Or alternatively, matched via glob patterns, this could be:
+Or alternatively, they can be specified explicitly (paths will be interpreted
+as glob patterns):
 
 .. code-block:: toml
 
     [project]
     license = "MIT AND (Apache-2.0 OR BSD-2-Clause)"
-    license-files.globs = [
-        "LICENSE*",
-        "setuptools/_vendor/LICENSE*",
+    license-files = [
+        "LICENSE",
+        "setuptools/_vendor/LICENSE",
+        "setuptools/_vendor/LICENSE.APACHE",
+        "setuptools/_vendor/LICENSE.BSD",
     ]
 
 With either approach, the output Core Metadata in the distribution
@@ -211,6 +212,7 @@ Some additional examples of valid ``License-Expression`` values:
     License-Expression: GPL-3.0-only WITH Classpath-Exception-2.0 OR BSD-3-Clause
     License-Expression: LicenseRef-Public-Domain OR CC0-1.0 OR Unlicense
     License-Expression: LicenseRef-Proprietary
+    License-Expression: LicenseRef-Custom-License
 
 
 .. _packaginglicense: https://github.com/pypa/packaging/blob/21.2/LICENSE