Drop python 3.9 support

[spoorcc]

Summary by CodeRabbit

Release Notes

• Chores

  • Dropped Python 3.9 support; minimum version is now 3.10.
  • Updated CI/CD pipelines to test Python 3.10–3.14.
  • Updated development tools to align with Python 3.10+ standards.

• Refactor

  • Modernized type annotations across the codebase to use Python 3.10+ union syntax for improved code clarity.

[coderabbitai]

Walkthrough

This PR drops Python 3.9 support and modernizes type annotations throughout the codebase to use PEP 604 union syntax. Updates include CI/CD workflows (Python 3.10–3.14 test matrix), tool configurations (pyupgrade, Pyright), minimum Python version requirement in pyproject.toml, and type hints across all modules (replacing Optional[T]/Union[A, B] with T | None/A | B).

Changes

Cohort / File(s)	Summary
CI/CD & Tooling Configuration .github/workflows/run.yml, .github/workflows/test.yml, .pre-commit-config.yaml, pyproject.toml	Updated Python test matrix to 3.10–3.14 (removed 3.9), refactored per-platform SVN installation steps, bumped minimum Python requirement and type-checker target version to 3.10, updated pyupgrade invocation from --py39-plus to --py310-plus.
Core Entry Point dfetch/__main__.py	Updated run() function signature to use union syntax (Console | None instead of Optional[Console]), removed Optional import.
Logging Module dfetch/log.py	Replaced Optional/Union with PEP 604 syntax across configure_root_logger(), setup_root(), get_logger(), and DLogger.status() signatures and internal variable annotations.
Manifest & Configuration dfetch/manifest/manifest.py, dfetch/manifest/parse.py, dfetch/manifest/project.py, dfetch/manifest/remote.py	Converted ManifestDict type fields and method signatures (e.g., Manifest.__init__, from_yaml, _load_yaml) to use union syntax; updated ProjectEntryDict and RemoteDict field types accordingly.
Project & Superproject Handling dfetch/project/__init__.py, dfetch/project/metadata.py, dfetch/project/subproject.py	Updated determine_superproject_vcs(), Options.patch, Metadata.fetched(), and SubProject return/parameter types to union syntax; removed Optional/Union imports.
VCS & Patch Utilities dfetch/vcs/git.py, dfetch/vcs/patch.py, dfetch/vcs/svn.py	Converted GitLocalRepo, SvnRepo, and parse_patch type annotations (path parameters, optional version/ignore parameters, return types) from Optional/Union to PEP 604 syntax.
General Utilities dfetch/util/cmdline.py, dfetch/util/license.py, dfetch/util/purl.py, dfetch/util/util.py, dfetch/util/versions.py, dfetch/commands/update_patch.py	Updated utility function and class signatures (e.g., run_on_cmdline(), guess_license_in_file(), safe_rm(), in_directory()) to use union syntax for optional and multi-type parameters.
Changelog CHANGELOG.rst	Added release note documenting Python 3.9 support removal in 0.12.0 (unreleased).

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

• #985 — Updates patch parsing and handling APIs in dfetch/vcs/patch.py alongside type annotation changes.
• #931 — Modifies manifest, project metadata, and subproject type annotations concurrently with similar union syntax conversions.
• #960 — Introduces Rich-based logging APIs (configure_root_logger, setup_root, get_logger, DLogger.status) that are type-annotated in this PR.

Suggested labels

enhancement

Suggested reviewers

• ben-edna

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and accurately summarizes the main objective of the pull request, which is to drop Python 3.9 support and upgrade to Python 3.10+.
Docstring Coverage	✅ Passed	Docstring coverage is 95.45% which is sufficient. The required threshold is 80.00%.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch drop-py39-support

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No actionable comments were generated in the recent review. 🎉

🧹 Recent nitpick comments

.github/workflows/run.yml (1)

83-102: Good improvement: per-platform SVN installation.

Splitting SVN installation into platform-specific conditional steps is cleaner than a single step. Consider giving each step a distinct name (e.g., "Install SVN (Ubuntu)", "Install SVN (macOS)", "Install SVN (Windows)") for easier log navigation, though this is a minor nit.

dfetch/util/license.py (1)

47-59: Docstring still references old-style type annotations.

The function signature now uses str | PathLike[str] and License | None, but the docstring on lines 56 and 59 still uses Union[str, os.PathLike[str]] and Optional[License]. Consider updating for consistency.

Proposed fix

     Args:
-        filename (Union[str, os.PathLike[str]]): Path to the file to analyze
+        filename (str | os.PathLike[str]): Path to the file to analyze
 
     Returns:
-        Optional[License]: The most probable license if found, None if no license could be detected
+        License | None: The most probable license if found, None if no license could be detected

dfetch/project/subproject.py (1)

44-49: Stale docstring still references old typing syntax.

Line 48 docstring still says Tuple[Optional[Version], Optional[Version]] while the actual return type is now tuple[Version | None, Version | None].

📝 Suggested docstring update

-            Tuple[Optional[Version], Optional[Version]]: Wanted, Have
+            tuple[Version | None, Version | None]: Wanted, Have

dfetch/manifest/manifest.py (1)

146-157: Docstring still uses old-style Union[...] notation.

The docstring on lines 149–151 still references Union[ProjectEntryDict, ProjectEntry, Dict[str, Union[str, list[str]]]] while the actual signature now uses PEP 604 syntax. Consider updating for consistency.

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