add unit tests for build scripts

[tejas0077]

Closes #1570

Adds unit tests for 4 build scripts as requested by @romanlutz in #1569.

• test_prepare_package.py — 9 tests covering npm lookup, install/build failures, and frontend copy logic
• test_validate_docs.py — 14 tests covering TOC parsing, missing file detection, and orphaned file checks
• test_generate_rss.py — 10 tests covering date extraction and blog markdown parsing
• test_check_links.py — 13 tests covering URL extraction, fragment stripping, and relative URL resolution

Added 46 unit tests across 4 new test files.
All 65 tests in tests/unit/build_scripts/ pass locally:

python -m pytest tests/unit/build_scripts/ -v

65 passed

No documentation changes required.
No JupyText changes required.

[Copilot]

Pull request overview

This PR adds unit tests under tests/unit/build_scripts/ to cover several Python build/validation scripts, improving reliability across platforms and catching regressions in packaging/docs/link-check tooling.

Changes:

• Added unit tests for validate_docs TOC parsing / missing-file validation / orphan detection.
• Added unit tests for prepare_package frontend build and packaging copy behavior.
• Added unit tests for generate_rss date extraction and blog markdown parsing, plus check_links URL extraction and resolution helpers.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 8 comments.

File	Description
tests/unit/build_scripts/test_prepare_package.py	Tests frontend build failure/success paths and frontend dist copy behavior.
tests/unit/build_scripts/test_validate_docs.py	Tests TOC parsing, referenced-file validation, and orphaned doc detection.
tests/unit/build_scripts/test_generate_rss.py	Tests filename date parsing and blog markdown parsing helpers.
tests/unit/build_scripts/test_check_links.py	Tests URL extraction, fragment stripping, and relative URL resolution.

[Copilot]

Inline import import subprocess inside the test function violates the repo style guide rule that imports must be at the top of the file (unless breaking a circular dependency). Move this import to the module import section.

[Copilot]

Inline import import subprocess inside the test function violates the repo style guide rule that imports must be at the top of the file (unless breaking a circular dependency). Move this import to the module import section.

[tejas0077]

FIXED

[Copilot]

Importing build_scripts.generate_rss executes substantial module-level code (generates/writes the RSS file and may sys.exit) rather than just defining functions. These unit tests import from that module, so they can become flaky and can write into the repo’s doc/_build during a unit test run. Consider refactoring generate_rss.py so executable logic is under a main() guarded by if __name__ == "__main__", or adjust tests to import the functions without executing the script body.

Suggested change

	import tempfile
	from pathlib import Path
	import pytest
	from build_scripts.generate_rss import extract_date_from_filename, parse_blog_markdown
	import ast
	from collections.abc import Callable
	from pathlib import Path
	from typing import Any
	import pytest
	def _load_generate_rss_functions() -> tuple[Callable[[str], str], Callable[[Path], tuple[str, str]]]:
	"""Load the generate_rss helpers without executing the script body."""
	script_path = Path(__file__).resolve().parents[3] / "build_scripts" / "generate_rss.py"
	source = script_path.read_text(encoding="utf-8")
	parsed_module = ast.parse(source, filename=str(script_path))
	target_functions = {"extract_date_from_filename", "parse_blog_markdown"}
	selected_nodes: list[ast.stmt] = []
	for node in parsed_module.body:
	if isinstance(node, (ast.Import, ast.ImportFrom)):
	selected_nodes.append(node)
	continue
	if isinstance(node, ast.FunctionDef) and node.name in target_functions:
	selected_nodes.append(node)
	safe_module = ast.Module(body=selected_nodes, type_ignores=[])
	namespace: dict[str, Any] = {}
	exec(compile(safe_module, filename=str(script_path), mode="exec"), namespace)
	return namespace["extract_date_from_filename"], namespace["parse_blog_markdown"]
	extract_date_from_filename, parse_blog_markdown = _load_generate_rss_functions()

[tejas0077]

FIXED

[Copilot]

Unused imports: tempfile and pytest are imported but never used in this test module. Please remove them to avoid lint failures and keep the test focused.

Suggested change

	import tempfile
	from pathlib import Path
	import pytest
	from pathlib import Path

[tejas0077]

FIXED

[Copilot]

Unused imports: shutil, tempfile, and pytest are imported but never used in this test module. This will fail linting (and adds noise); please remove them.

Suggested change

	import shutil
	import tempfile
	from pathlib import Path
	from unittest.mock import MagicMock, patch
	import pytest
	from pathlib import Path
	from unittest.mock import MagicMock, patch

[tejas0077]

FIXED