Replace pkg_resources by importlib.resources (#496)

pyproject.toml

@@ -32,9 +32,9 @@ requires-python = ">=3.7"
 dependencies = [
     "click",
     "click-default-group",
+    "importlib-resources>1.3; python_version<'3.9'",
     "incremental",
     "jinja2",
-    "setuptools",
     "tomli; python_version<'3.11'",
 ]
 

src/towncrier/_settings/load.py

@@ -3,15 +3,15 @@
 
 from __future__ import annotations
 
+import atexit
 import os
 import sys
 
 from collections import OrderedDict
+from contextlib import ExitStack
 from dataclasses import dataclass
 from typing import TYPE_CHECKING, Any, Mapping
 
-import pkg_resources
-
 from .._settings import fragment_types as ft
 
 
@@ -23,6 +23,12 @@
     else:
         from typing import Literal
 
+if sys.version_info < (3, 9):
+    import importlib_resources as resources
+else:
+    from importlib import resources
+
+
 if sys.version_info < (3, 11):
     import tomli as tomllib
 else:
@@ -106,6 +112,11 @@ def load_config_from_file(directory: str, config_file: str) -> Config:
     return parse_toml(directory, config)
 
 
+# Clean up possible temporary files on exit.
+_file_manager = ExitStack()
+atexit.register(_file_manager.close)
+
+
 def parse_toml(base_path: str, config: Mapping[str, Any]) -> Config:
     if "tool" not in config:
         raise ConfigError("No [tool.towncrier] section.", failing_option="all")
@@ -146,14 +157,18 @@ def parse_toml(base_path: str, config: Mapping[str, Any]) -> Config:
 
     template = config.get("template", _template_fname)
     if template.startswith("towncrier:"):
-        resource_name = "templates/" + template.split("towncrier:", 1)[1] + ".rst"
-        if not pkg_resources.resource_exists("towncrier", resource_name):
+        resource_name = f"templates/{template.split('towncrier:', 1)[1]}.rst"
+        resource_path = _file_manager.enter_context(
+            resources.as_file(resources.files("towncrier") / resource_name)
+        )
+
+        if not resource_path.is_file():
             raise ConfigError(
                 "Towncrier does not have a template named '%s'."
                 % (template.split("towncrier:", 1)[1],)
             )
 
-        template = pkg_resources.resource_filename("towncrier", resource_name)
+        template = str(resource_path)
     else:
         template = os.path.join(base_path, template)
 

src/towncrier/newsfragments/496.feature

@@ -0,0 +1 @@
+Towncrier no longer depends on setuptools & uses importlib.resources (or its backport) instead.

src/towncrier/test/helpers.py

@@ -1,12 +1,20 @@
 from __future__ import annotations
 
+import sys
+
 from functools import wraps
 from pathlib import Path
 from typing import Any, Callable
 
 from click.testing import CliRunner
 
 
+if sys.version_info < (3, 9):
+    import importlib_resources as resources
+else:
+    from importlib import resources
+
+
 def read(filename: str | Path) -> str:
     return Path(filename).read_text()
 
@@ -20,6 +28,13 @@ def write(path: str | Path, contents: str) -> None:
     p.write_text(contents)
 
 
+def read_pkg_resource(path: str) -> str:
+    """
+    Read *path* from the towncrier package.
+    """
+    return (resources.files("towncrier") / path).read_text("utf8")
+
+
 def with_isolated_runner(fn: Callable[..., Any]) -> Callable[..., Any]:
     """
     Run *fn* within an isolated filesystem and add the kwarg *runner* to its

src/towncrier/test/test_format.py

@@ -4,11 +4,10 @@
 
 from collections import OrderedDict
 
-import pkg_resources
-
 from twisted.trial.unittest import TestCase
 
 from .._builder import render_fragments, split_fragments
+from .helpers import read_pkg_resource
 
 
 class FormatterTests(TestCase):
@@ -119,9 +118,7 @@ def test_basic(self):
 - Web fixed. (#3)
 """
 
-        template = pkg_resources.resource_string(
-            "towncrier", "templates/default.rst"
-        ).decode("utf8")
+        template = read_pkg_resource("templates/default.rst")
 
         fragments = split_fragments(fragments, definitions)
         output = render_fragments(
@@ -208,9 +205,7 @@ def test_issue_format(self):
 - xxbar, xx1, xx9, xx142
 """
 
-        template = pkg_resources.resource_string(
-            "towncrier", "templates/default.rst"
-        ).decode("utf8")
+        template = read_pkg_resource("templates/default.rst")
 
         fragments = split_fragments(fragments, definitions)
         output = render_fragments(
@@ -266,9 +261,7 @@ def test_line_wrapping(self):
   a a (#3)
 """
 
-        template = pkg_resources.resource_string(
-            "towncrier", "templates/default.rst"
-        ).decode("utf8")
+        template = read_pkg_resource("templates/default.rst")
 
         fragments = split_fragments(fragments, definitions)
         output = render_fragments(
@@ -317,9 +310,7 @@ def test_line_wrapping_disabled(self):
 - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a (#3)
 """  # NOQA
 
-        template = pkg_resources.resource_string(
-            "towncrier", "templates/default.rst"
-        ).decode("utf8")
+        template = read_pkg_resource("templates/default.rst")
 
         fragments = split_fragments(fragments, definitions)
         output = render_fragments(

src/towncrier/test/test_write.py

@@ -7,14 +7,13 @@
 from pathlib import Path
 from textwrap import dedent
 
-import pkg_resources
-
 from click.testing import CliRunner
 from twisted.trial.unittest import TestCase
 
 from .._builder import render_fragments, split_fragments
 from .._writer import append_to_newsfile
 from ..build import _main
+from .helpers import read_pkg_resource
 
 
 class WritingTests(TestCase):
@@ -92,9 +91,7 @@ def test_append_at_top(self):
 
         fragments = split_fragments(fragments, definitions)
 
-        template = pkg_resources.resource_string(
-            "towncrier", "templates/default.rst"
-        ).decode("utf8")
+        template = read_pkg_resource("templates/default.rst")
 
         append_to_newsfile(
             tempdir,
@@ -205,9 +202,7 @@ def test_append_at_top_with_hint(self):
 
         fragments = split_fragments(fragments, definitions)
 
-        template = pkg_resources.resource_string(
-            "towncrier", "templates/default.rst"
-        ).decode("utf8")
+        template = read_pkg_resource("templates/default.rst")
 
         append_to_newsfile(
             tempdir,
@@ -242,9 +237,7 @@ def test_multiple_file_no_start_string(self):
         definitions = {}
         fragments = split_fragments(fragments={}, definitions=definitions)
 
-        template = pkg_resources.resource_string(
-            "towncrier", "templates/default.rst"
-        ).decode("utf8")
+        template = read_pkg_resource("templates/default.rst")
 
         content = render_fragments(
             template=template,