This commit introduces a complete structural and architectural refactor of

Analysis-Ready Code (ARC). The project is now fully migrated to a modern
src/-based Python package layout, with proper packaging via pyproject.toml,
a clean Nix flake, and improved CLI entry points.

Major changes:

• Add `src/arc/` package with clean module structure:
  - arc/__init__.py now contains the main() dispatcher and clipboard helpers
  - arc/__main__.py provides a proper `python -m arc` entry point
  - arc/cli.py rewritten with full argparse-based interface
  - arc/code_processor.py modernized and relocated
  - arc/directory_handler.py rewritten with output_stream support
  - arc/tee.py added for multi-stream output (stdout + buffer)

• Remove legacy top-level modules:
  - cli.py
  - directory_handler.py
  - main.py

• Introduce fully PEP-517 compliant pyproject.toml with console script:
  - arc = arc.__main__:main

• Add Nix flake (`flake.nix`) providing:
  - buildPythonApplication package `arc`
  - `nix run .#arc` app
  - development shell with Python + xclip

• Add Makefile overhaul:
  - automatic detection of Nix vs Python installation
  - unified install/uninstall targets
  - Nix wrapper installation into ~/.local/bin
  - improved help text and shell safety

• Add GitHub CI pipelines:
  - ci-python.yml for Python builds + Makefile tests + arc --help
  - ci-nix.yml for Nix builds, flake checks, dev-shell tests, and `nix run .#arc`

• Refactor and extend unit tests:
  - test_arc.py updated for src/ imports
  - new tests: test_cli.py, test_main.py, test_tee.py
  - improved CodeProcessor and DirectoryHandler tests

• Add egg-info metadata for local builds

• Add build/lib/ tree for compatibility with setuptools (generated)

Overall, this commit modernizes ARC into a clean, robust, and fully packaged
Python/Nix hybrid tool, enabling reproducible builds, solid CLI behavior,
testable architecture, and CI automation.

https://chatgpt.com/share/693933a0-e280-800f-9cf0-26036d15be04

tests/unit/test_cli.py

@@ -0,0 +1,60 @@
+# tests/unit/test_cli.py
+import os
+import sys
+import unittest
+from unittest.mock import patch
+
+# Ensure src/ is on sys.path when running via discover
+PROJECT_ROOT = os.path.abspath(os.path.join(os.path.dirname(__file__), "..", ".."))
+SRC_ROOT = os.path.join(PROJECT_ROOT, "src")
+if SRC_ROOT not in sys.path:
+    sys.path.insert(0, SRC_ROOT)
+
+from arc.cli import parse_arguments  # noqa: E402
+
+
+class TestCliParseArguments(unittest.TestCase):
+    def test_basic_paths_and_defaults(self):
+        with patch.object(sys, "argv", ["arc", "foo", "bar"]):
+            args = parse_arguments()
+
+        self.assertEqual(args.paths, ["foo", "bar"])
+        self.assertEqual(args.file_types, [])
+        self.assertEqual(args.ignore_file_strings, [])
+        self.assertFalse(args.clipboard)
+        self.assertFalse(args.quiet)
+        # show_hidden default is False → ignore_hidden should be True
+        self.assertFalse(args.show_hidden)
+        self.assertTrue(args.ignore_hidden)
+
+    def test_clipboard_and_quiet_short_flags(self):
+        with patch.object(sys, "argv", ["arc", ".", "-x", "-q"]):
+            args = parse_arguments()
+
+        self.assertTrue(args.clipboard)
+        self.assertTrue(args.quiet)
+
+    def test_ignore_file_strings_short_and_long(self):
+        # Test only the short form -I collecting multiple values
+        with patch.object(
+            sys,
+            "argv",
+            ["arc", ".", "-I", "build", "dist", "node_modules"],
+        ):
+            args = parse_arguments()
+
+        self.assertEqual(
+            args.ignore_file_strings,
+            ["build", "dist", "node_modules"],
+        )
+
+    def test_show_hidden_switches_ignore_hidden_off(self):
+        with patch.object(sys, "argv", ["arc", ".", "--show-hidden"]):
+            args = parse_arguments()
+
+        self.assertTrue(args.show_hidden)
+        self.assertFalse(args.ignore_hidden)
+
+
+if __name__ == "__main__":
+    unittest.main()