Check if any news fragments have invalid filenames

docs/cli.rst

@@ -64,6 +64,11 @@ also remove the fragments directory if now empty.
 
    Don't delete news fragments after the build and don't ask for confirmation whether to delete or keep the fragments.
 
+.. option:: --strict
+
+   Fail if there are any news fragments that have invalid filenames.
+   This is automatically turned on if ``build_ignore_filenames`` has been set in the configuration.
+
 
 ``towncrier create``
 --------------------

docs/configuration.rst

@@ -130,6 +130,13 @@ Top level keys
 
     ``true`` by default.
 
+``build_ignore_filenames``
+    A list of filenames in the news fragments directory to ignore when building the news file.
+
+    If this is configured, it turns on the ``--strict`` build mode which will fail if there are any news fragment files not in this list that have invalid filenames. Note that if a template is used, it should also be included here.
+
+    ``None`` by default.
+
 Extra top level keys for Python projects
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

docs/tutorial.rst

@@ -47,6 +47,11 @@ Create this folder::
 
 The ``.gitignore`` will remain and keep Git from not tracking the directory.
 
+If needed, you can also specify a list of filenames for ``towncrier`` to ignore in the news fragments directory::
+
+   [tool.towncrier]
+   build_ignore_filenames = ["README.rst"]
+
 
 Detecting Version
 -----------------

src/towncrier/_builder.py

@@ -12,6 +12,7 @@
 from pathlib import Path
 from typing import Any, DefaultDict, Iterable, Iterator, Mapping, NamedTuple, Sequence
 
+from click import ClickException
 from jinja2 import Template
 
 from towncrier._settings.load import Config
@@ -106,10 +107,22 @@ def __call__(self, section_directory: str = "") -> str:
 def find_fragments(
     base_directory: str,
     config: Config,
+    strict: bool | None,
 ) -> tuple[Mapping[str, Mapping[tuple[str, str, int], str]], list[tuple[str, str]]]:
     """
     Sections are a dictonary of section names to paths.
+
+    In strict mode, raise ClickException if any fragments have an invalid name.
     """
+    if strict is None:
+        # If strict mode is not set, turn it on only if build_ignore_filenames is set
+        # (this maintains backward compatibility).
+        strict = config.build_ignore_filenames is not None
+
+    ignored_files = {".gitignore"}
+    if config.build_ignore_filenames:
+        ignored_files.update(config.build_ignore_filenames)
+
     get_section_path = FragmentsPath(base_directory, config)
 
     content = {}
@@ -129,10 +142,20 @@ def find_fragments(
         file_content = {}
 
         for basename in files:
+            # Skip files that are deliberately ignored
+            if basename in ignored_files:
+                continue
+
             issue, category, counter = parse_newfragment_basename(
                 basename, config.types
             )
             if category is None:
+                if strict and issue is None:
+                    raise ClickException(
+                        f"Invalid news fragment name: {basename}\n"
+                        "If this filename is deliberate, add it to "
+                        "'build_ignore_filenames' in your configuration."
+                    )
                 continue
             assert issue is not None
             assert counter is not None

src/towncrier/_settings/load.py

@@ -54,6 +54,7 @@ class Config:
     orphan_prefix: str = "+"
     create_eof_newline: bool = True
     create_add_extension: bool = True
+    build_ignore_filenames: list[str] | None = None
 
 
 class ConfigError(ClickException):

src/towncrier/build.py

@@ -106,6 +106,17 @@ def _validate_answer(ctx: Context, param: Option, value: bool) -> bool:
     help="Do not ask for confirmations. But keep news fragments.",
     callback=_validate_answer,
 )
+@click.option(
+    "--strict",
+    "strict",
+    default=None,
+    flag_value=True,
+    help=(
+        "Fail if there are any news fragments that have invalid filenames (this is "
+        "automatically turned on if 'build_ignore_filenames' has been set in the "
+        "configuration)."
+    ),
+)
 def _main(
     draft: bool,
     directory: str | None,
@@ -115,6 +126,7 @@ def _main(
     project_date: str | None,
     answer_yes: bool,
     answer_keep: bool,
+    strict: bool | None,
 ) -> None:
     """
     Build a combined news file from news fragment.
@@ -129,6 +141,7 @@ def _main(
             project_date,
             answer_yes,
             answer_keep,
+            strict,
         )
     except ConfigError as e:
         print(e, file=sys.stderr)
@@ -144,6 +157,7 @@ def __main(
     project_date: str | None,
     answer_yes: bool,
     answer_keep: bool,
+    strict: bool | None,
 ) -> None:
     """
     The main entry point.
@@ -178,7 +192,7 @@ def __main(
 
     click.echo("Finding news fragments...", err=to_err)
 
-    fragment_contents, fragment_files = find_fragments(base_directory, config)
+    fragment_contents, fragment_files = find_fragments(base_directory, config, strict)
     fragment_filenames = [filename for (filename, _category) in fragment_files]
 
     click.echo("Rendering news fragments...", err=to_err)

src/towncrier/check.py

@@ -101,12 +101,14 @@ def __main(
         click.echo(f"{n}. {change}")
     click.echo("----")
 
+    # This will fail if any fragment files have an invalid name:
+    all_fragment_files = find_fragments(base_directory, config, strict=True)[1]
+
     news_file = os.path.normpath(os.path.join(base_directory, config.filename))
     if news_file in files:
         click.echo("Checks SKIPPED: news file changes detected.")
         sys.exit(0)
 
-    all_fragment_files = find_fragments(base_directory, config)[1]
     fragments = set()  # will only include fragments of types that are checked
     unchecked_fragments = set()  # will include fragments of types that are not checked
     for fragment_filename, category in all_fragment_files:

src/towncrier/newsfragments/622.feature.rst

@@ -0,0 +1,3 @@
+``towncrier check`` will now fail if any news fragments have invalid filenames.
+
+Added a new configuration option called ``build_ignore_filenames`` that allows you to specify a list of filenames that should be ignored. If this is set, ``towncrier build`` will also fail if any filenames are invalid, except for those in the list.

src/towncrier/test/test_build.py

@@ -1530,3 +1530,60 @@ def test_orphans_in_non_showcontent_markdown(self, runner):
 
         self.assertEqual(0, result.exit_code, result.output)
         self.assertEqual(expected_output, result.output)
+
+    @with_project(
+        config="""
+        [tool.towncrier]
+        package = "foo"
+        build_ignore_filenames = ["template.jinja", "CAPYBARAS.md"]
+        """
+    )
+    def test_invalid_fragment_names(self, runner):
+        """
+        When build_ignore_filenames is set, files with those names are ignored.
+        """
+        opts = ["--draft", "--date", "01-01-2001", "--version", "1.0.0"]
+        # Valid filename:
+        with open("foo/newsfragments/123.feature", "w") as f:
+            f.write("Adds levitation")
+        # Files that should be ignored:
+        with open("foo/newsfragments/template.jinja", "w") as f:
+            f.write("Jinja template")
+        with open("foo/newsfragments/CAPYBARAS.md", "w") as f:
+            f.write("Peanut butter")
+        # Automatically ignored:
+        with open("foo/newsfragments/.gitignore", "w") as f:
+            f.write("!.gitignore")
+
+        result = runner.invoke(_main, opts)
+        # Should succeed
+        self.assertEqual(0, result.exit_code, result.output)
+
+        # Invalid filename:
+        with open("foo/newsfragments/feature.124", "w") as f:
+            f.write("Extends levitation")
+
+        result = runner.invoke(_main, opts)
+        # Should now fail
+        self.assertEqual(1, result.exit_code, result.output)
+        self.assertIn("Invalid news fragment name: feature.124", result.output)
+
+    @with_project()
+    def test_invalid_fragment_names_strict(self, runner):
+        """
+        When using --strict, any invalid filenames will cause an error even if
+        build_ignore_filenames is NOT set.
+        """
+        opts = ["--draft", "--date", "01-01-2001", "--version", "1.0.0"]
+        # Invalid filename:
+        with open("foo/newsfragments/feature.124", "w") as f:
+            f.write("Extends levitation")
+
+        result = runner.invoke(_main, opts)
+        # Should succeed in normal mode
+        self.assertEqual(0, result.exit_code, result.output)
+
+        result = runner.invoke(_main, [*opts, "--strict"])
+        # Should now fail
+        self.assertEqual(1, result.exit_code, result.output)
+        self.assertIn("Invalid news fragment name: feature.124", result.output)

src/towncrier/test/test_check.py

@@ -470,3 +470,23 @@ def test_in_different_dir_with_nondefault_newsfragments_directory(self, runner):
         self.assertTrue(
             result.output.endswith("No new newsfragments found on this branch.\n")
         )
+
+    @with_isolated_runner
+    def test_invalid_fragment_name(self, runner):
+        create_project("pyproject.toml")
+        opts = ["--compare-with", "main"]
+
+        write("foo/bar.py", "# Scorpions!")
+        write("foo/newsfragments/123.feature", "Adds scorpions")
+        write("foo/newsfragments/.gitignore", "!.gitignore")
+        commit("add stuff")
+
+        result = runner.invoke(towncrier_check, opts)
+        self.assertEqual(0, result.exit_code, result.output)
+
+        # Make invalid filename:
+        os.rename("foo/newsfragments/123.feature", "foo/newsfragments/feature.123")
+
+        result = runner.invoke(towncrier_check, opts)
+        self.assertEqual(1, result.exit_code, result.output)
+        self.assertIn("Invalid news fragment name: feature.123", result.output)