test: add pytest suite for core modules

- Add pytest dependency and config to pyproject.toml
- Test project_root: env var priority, fallback, directory creation
- Test CLI: help, version, subcommands, default behavior, options

tests/test_project_root.py

@@ -0,0 +1,80 @@
+"""Tests for myclaude.project_root."""
+
+import os
+from pathlib import Path
+from unittest.mock import patch
+
+from myclaude.project_root import get_myclaude_project_root, get_workspace_root
+
+
+class TestGetMyclaudeProjectRoot:
+    """Tests for get_myclaude_project_root."""
+
+    def test_env_var_takes_priority(self, tmp_path: Path) -> None:
+        """MYCLAUDE_PROJECT_ROOT env var should be used when set."""
+        fake_root = tmp_path / "fake_repo"
+        fake_root.mkdir()
+        (fake_root / "pyproject.toml").write_text('name = "myclaude"\n')
+
+        with patch.dict(os.environ, {"MYCLAUDE_PROJECT_ROOT": str(fake_root)}):
+            result = get_myclaude_project_root()
+            assert result == fake_root.resolve()
+
+    def test_fallback_when_not_in_repo(self) -> None:
+        """When not in a repo, fallback to ~/.myclaude."""
+        with patch.dict(os.environ, {}, clear=True):
+            with patch("pathlib.Path.cwd", side_effect=OSError):
+                with patch("myclaude.project_root._pyproject_names_myclaude", return_value=False):
+                    result = get_myclaude_project_root()
+                    assert result == Path.home() / ".myclaude"
+
+
+class TestGetWorkspaceRoot:
+    """Tests for get_workspace_root."""
+
+    def test_env_var_takes_priority(self, tmp_path: Path) -> None:
+        """MYCLAUDE_WORKSPACE_ROOT env var should be used when set."""
+        custom = tmp_path / "custom_workspace"
+
+        with patch.dict(os.environ, {"MYCLAUDE_WORKSPACE_ROOT": str(custom)}):
+            result = get_workspace_root()
+            assert result == custom.resolve()
+            assert result.is_dir()
+
+    def test_creates_directory_if_missing(self, tmp_path: Path) -> None:
+        """Should create the workspace directory if it doesn't exist."""
+        new_ws = tmp_path / "new_workspace"
+        assert not new_ws.exists()
+
+        with patch.dict(os.environ, {"MYCLAUDE_WORKSPACE_ROOT": str(new_ws)}):
+            result = get_workspace_root()
+            assert result == new_ws.resolve()
+            assert result.is_dir()
+
+    def test_defaults_to_project_workspace(self, tmp_path: Path) -> None:
+        """When project_root/workspace exists, use it."""
+        project_root = tmp_path / "myclaude"
+        project_root.mkdir()
+        workspace = project_root / "workspace"
+        workspace.mkdir()
+        (project_root / "pyproject.toml").write_text('name = "myclaude"\n')
+
+        with patch.dict(os.environ, {"MYCLAUDE_PROJECT_ROOT": str(project_root)}, clear=True):
+            result = get_workspace_root()
+            assert result == workspace.resolve()
+
+    def test_defaults_to_home_workspace(self, tmp_path: Path) -> None:
+        """When no env var and no project workspace, default to ~/workspace."""
+        with (
+            patch.dict(os.environ, {}, clear=True),
+            patch("myclaude.project_root.get_myclaude_project_root", return_value=tmp_path / ".myclaude"),
+            patch.dict(os.environ, {}, clear=True),
+        ):
+            with patch.dict(os.environ, {}, clear=True):
+                # Ensure HOME is set for Path.home()
+                home = tmp_path / "home"
+                home.mkdir()
+                with patch("pathlib.Path.home", return_value=home):
+                    result = get_workspace_root()
+                    assert result == home / "workspace"
+                    assert result.is_dir()