infra: switch to flit

CHANGELOG.rst

@@ -3,6 +3,16 @@ Changelog
 +++++++++
 
 
+Unreleased
+==========
+
+- Change build backend from ``setuptools`` to ``flit``
+  (`PR #470`_, Fixes `#394`_)
+
+.. _PR #470: https://github.com/pypa/build/pull/470
+.. _#394: https://github.com/pypa/build/issues/394
+
+
 0.9.0 (2022-10-27)
 ==================
 

pyproject.toml

@@ -1,6 +1,79 @@
 [build-system]
-requires = ["setuptools >=42.0"]
-build-backend = "setuptools.build_meta"
+requires = ["flit-core >= 3.4"]
+build-backend = "flit_core.buildapi"
+
+[project]
+name = "build"
+version = "0.9.0"
+description = "A simple, correct PEP 517 build frontend"
+readme = "README.md"
+requires-python = ">= 3.6"
+license.file = "LICENSE"
+authors = [
+  { name = "Filipe Laíns", email = "lains@riseup.net" },
+  { name = "Bernát Gábor", email = "gaborjbernat@gmail.com" },
+  { name = "layday", email = "layday@protonmail.com" },
+  { name = "Henry Schreiner", email = "henryschreineriii@gmail.com" },
+]
+classifiers = [
+  "License :: OSI Approved :: MIT License",
+  "Programming Language :: Python :: 3",
+  "Programming Language :: Python :: 3 :: Only",
+  "Programming Language :: Python :: 3.6",
+  "Programming Language :: Python :: 3.7",
+  "Programming Language :: Python :: 3.8",
+  "Programming Language :: Python :: 3.9",
+  "Programming Language :: Python :: 3.10",
+  "Programming Language :: Python :: 3.11",
+  "Programming Language :: Python :: Implementation :: CPython",
+  "Programming Language :: Python :: Implementation :: PyPy",
+]
+urls.homepage = "https://github.com/pypa/build"
+urls.changelog = "https://pypa-build.readthedocs.io/en/stable/changelog.html"
+
+dependencies = [
+  "packaging >= 19.0",
+  "pep517 >= 0.9.1",
+  # not actually a runtime dependency, only supplied as there is not "recommended dependency" support
+  'colorama; os_name == "nt"',
+  'importlib-metadata >= 0.22; python_version < "3.8"',
+  # toml can be used instead -- in case it makes bootstrapping easier
+  'tomli >= 1.0.0; python_version < "3.11"',
+]
+
+[project.optional-dependencies]
+docs = [
+  "furo >= 2021.08.31",
+  "sphinx ~= 4.0",
+  "sphinx-argparse-cli >= 1.5",
+  "sphinx-autodoc-typehints >= 1.10",
+]
+test = [
+  "filelock >= 3",
+  "pytest >= 6.2.4",
+  "pytest-cov >= 2.12",
+  "pytest-mock >= 2",
+  "pytest-rerunfailures >= 9.1",
+  "pytest-xdist >= 1.34",
+  "toml >= 0.10.0",
+  "wheel >= 0.36.0",
+  'setuptools >= 42.0.0; python_version < "3.10"',
+  'setuptools >= 56.0.0; python_version >= "3.10"',
+]
+typing = [
+  "importlib-metadata >= 4.6.4",
+  "mypy == 0.942",
+  "typing-extensions >= 3.7.4.3",
+]
+virtualenv = [
+  "virtualenv >= 20.0.35",
+]
+
+[project.scripts]
+pyproject-build = "build.__main__:entrypoint"
+
+[project.entry-points."pipx.run"]
+build = "build.__main__:entrypoint"
 
 [tool.coverage.run]
 source = [
@@ -49,7 +122,6 @@ strict = true
 show_error_codes = true
 enable_error_code = ["ignore-without-code", "truthy-bool", "redundant-expr"]
 
-
 [[tool.mypy.overrides]]
 module = [
   "colorama",   # Optional dependency

tests/test_integration.py

@@ -93,8 +93,8 @@ def _ignore_folder(base, filenames):
 )
 @pytest.mark.isolated
 def test_build(monkeypatch, project, args, call, tmp_path):
-    if project == 'flit' and '--no-isolation' in args:
-        pytest.xfail("can't build flit without isolation due to missing dependencies")
+    if project in {'build', 'flit'} and '--no-isolation' in args:
+        pytest.xfail(f"can't build {project} without isolation due to missing dependencies")
     if project == 'Solaar' and IS_WINDOWS and IS_PYPY3:
         pytest.xfail('Solaar fails building wheels via sdists on Windows on PyPy 3')
 

tests/test_self_packaging.py

@@ -18,17 +18,6 @@
     'PKG-INFO',
     'README.md',
     'pyproject.toml',
-    'setup.cfg',
-    'setup.py',
-    'src',
-    'src/build',
-    'src/build.egg-info',
-    'src/build.egg-info/PKG-INFO',
-    'src/build.egg-info/SOURCES.txt',
-    'src/build.egg-info/dependency_links.txt',
-    'src/build.egg-info/entry_points.txt',
-    'src/build.egg-info/requires.txt',
-    'src/build.egg-info/top_level.txt',
     'src/build/__init__.py',
     'src/build/__main__.py',
     'src/build/env.py',
@@ -47,7 +36,6 @@
     'dist-info/RECORD',
     'dist-info/WHEEL',
     'dist-info/entry_points.txt',
-    'dist-info/top_level.txt',
 }
 
 
@@ -70,7 +58,7 @@ def test_build_sdist(monkeypatch, tmpdir):
     (sdist,) = tmpdir.visit('*.tar.gz')
 
     with tarfile.open(str(sdist), 'r:gz') as tar:
-        simpler = {n.split('/', 1)[-1] for n in tar.getnames()[1:]}
+        simpler = {n.split('/', 1)[-1] for n in tar.getnames()}
 
     assert simpler == sdist_files