Modernize the packaging setup via PEP 621 and Hatch.

Doing so jettisons setuptools in favor of a more modern, well-designed,
legacy-free, and now well-supported packaging tool, Hatch.

No end-user facing behavior changes are expected for any users using a
recent packaging setup (within the past 2-3 years), so please report any
issues.

Hatch: https://hatch.pypa.io/latest/
PEP 621: https://peps.python.org/pep-0621/

.flake8

@@ -0,0 +1,10 @@
+[flake8]
+ban-relative-imports = true
+inline-quotes = "
+exclude =
+    jsonschema/__init__.py
+    jsonschema/_reflect.py
+ignore =
+    B008,  # Barring function calls in default args. Ha, no.
+    B306,  # See https://github.com/PyCQA/flake8-bugbear/issues/131
+    W503,  # (flake8 default) old PEP8 boolean operator line breaks

docs/validate.rst

@@ -205,7 +205,7 @@ to validate. Their names can be viewed by inspecting the
 `FormatChecker.checkers` attribute. Certain checkers will only be
 available if an appropriate package is available for use. The easiest way to
 ensure you have what is needed is to install ``jsonschema`` using the
-``format`` or ``format_nongpl`` setuptools extra -- i.e.
+``format`` or ``format_nongpl`` collection of optional dependencies -- e.g.
 
 .. code-block:: sh
 

pyproject.toml

@@ -1,16 +1,97 @@
 [build-system]
-requires = [
-    # The minimum setuptools version is specific to the PEP 517 backend,
-    # and may be stricter than the version required in `setup.py`
-    "setuptools>=40.6.0",
-    "setuptools_scm[toml]>=3.4",
-    "wheel",
+requires = ["hatchling", "hatch-vcs"]
+build-backend = "hatchling.build"
+
+[tool.hatch.version]
+source = "vcs"
+
+[project]
+name = "jsonschema"
+description = "An implementation of JSON Schema validation for Python"
+readme = "README.rst"
+requires-python = ">=3.7"
+license = {text = "MIT"}
+keywords = ["validation", "data validation", "jsonschema", "json"]
+authors = [
+  {email = "Julian+jsonschema@GrayVines.com"},
+  {name = "Julian Berman"},
+]
+classifiers = [
+  "Development Status :: 5 - Production/Stable",
+  "Intended Audience :: Developers",
+  "License :: OSI Approved :: MIT License",
+  "Operating System :: OS Independent",
+  "Programming Language :: Python",
+  "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",
+]
+dynamic = ["version"]
+
+dependencies = [
+  "attrs>=17.4.0",
+  "pyrsistent>=0.14.0,!=0.17.0,!=0.17.1,!=0.17.2",
+
+  "importlib_metadata;python_version<'3.8'",
+  "typing_extensions;python_version<'3.8'",
+  "importlib_resources>=1.4.0;python_version<'3.9'",
+]
+
+[project.optional-dependencies]
+format = [
+  "fqdn",
+  "idna",
+  "isoduration",
+  "jsonpointer>1.13",
+  "rfc3339-validator",
+  "rfc3987",
+  "uri_template",
+  "webcolors>=1.11",
+]
+format_nongpl = [
+  "fqdn",
+  "idna",
+  "isoduration",
+  "jsonpointer>1.13",
+  "rfc3339-validator",
+  "rfc3986-validator>0.1.0",
+  "uri_template",
+  "webcolors>=1.11",
 ]
-build-backend = "setuptools.build_meta"
+
+[project.scripts]
+jsonschema = "jsonschema.cli:main"
+
+[project.urls]
+homepage = "github.com/python-jsonschema/jsonschema"
+documentation = "python-jsonschema.readthedocs.io/en/latest/"
+issues = "github.com/python-jsonschema/jsonschema/issues/"
+funding = "github.com/sponsors/Julian"
+tidelift = "tidelift.com/subscription/pkg/pypi-jsonschema?utm_source=pypi-jsonschema&utm_medium=referral&utm_campaign=pypi-link"
+changelog = "github.com/python-jsonschema/jsonschema/blob/main/CHANGELOG.rst"
+source = "github.com/python-jsonschema/jsonschema"
 
 [tool.isort]
 from_first = true
 include_trailing_comma = true
 multi_line_output = 3
 
-[tool.setuptools_scm]
+[tool.mypy]
+ignore_missing_imports = true
+
+[tool.pydocstyle]
+match = "(?!(test_|_|compat|cli)).*\\.py"  # see PyCQA/pydocstyle#323
+add-select = [
+  "D410", # Trailing whitespace plz
+]
+add-ignore = [
+  "D107",  # Hah, no
+  "D200",  # 1-line docstrings don't need to be on one line
+  "D202",  # One line is fine.
+  "D412",  # Trailing whitespace plz
+  "D413",  # No trailing whitespace plz
+]

tox.ini

@@ -97,7 +97,7 @@ deps =
     pyrsistent
     types-attrs
     types-requests
-commands = {envpython} -m mypy --config {toxinidir}/setup.cfg {posargs} {toxinidir}/jsonschema
+commands = {envpython} -m mypy --config {toxinidir}/pyproject.toml {posargs} {toxinidir}/jsonschema
 
 [testenv:docs-dirhtml]
 commands = {envpython} -m sphinx -b dirhtml {toxinidir}/docs/ {envtmpdir}/build {posargs:-a -n -q -T -W}