refactor(testing.pytest): change mock_pkg interface

being more explicit about what the fixture provides as an output, instead of
solely describing the site effects.

Also the consumer is now responsible for the module directory layout.

src/byteb4rb1e/testing/pytest/fixtures.py

@@ -7,6 +7,8 @@ import pytest
 
 from byteb4rb1e.testing.pytest import get_current_test
 
+_SITE_PACKAGE_COUNTER: Dict[str, int] = {}
+
 
 @pytest.fixture
 def current_test() -> Tuple[Path, str]:
@@ -16,25 +18,27 @@ def current_test() -> Tuple[Path, str]:
 
 
 @pytest.fixture
-def mock_pkg(tmp_path):
+def mock_system_site_package_dir(tmp_path):
-    def _create(name: str, files: Dict[str, Union[str, bytes]]):
+    global _SITE_PACKAGE_COUNTER
-        pkg_path = tmp_path / name.replace('.', os.path.sep)
+
+    package_id = _SITE_PACKAGE_COUNTER.setdefault(tmp_path, 0)
+    _SITE_PACKAGE_COUNTER[tmp_path] += 1
+
+    sys_path = tmp_path / str(package_id)
+
+    def _create(name: str) -> Path:
+        pkg_path = sys_path / name.replace('.', os.path.sep)
+
         pkg_path.mkdir(parents=True)
+
         (pkg_path / "__init__.py").touch()
 
-        for fname, content in files.items():
+        sys.path.insert(0, str(sys_path))
-            fpath = (pkg_path / fname)
-            fpath.parent.mkdir(parents=True, exist_ok=True)
-            if isinstance(content, str):
-                fpath.write_text(content)
-            else:
-                fpath.write_bytes(content)
 
-        sys.path.insert(0, str(tmp_path))
+        return pkg_path
-        return name, pkg_path
 
     yield _create
 
     # cleanup sys.path after test
-    if str(tmp_path) in sys.path:
+    if str(sys_path) in sys.path:
-        sys.path.remove(str(tmp_path))
+        sys.path.remove(str(sys_path))

tests/integration/byteb4rb1e/testing/pytest/test_fixtures.py

@@ -6,7 +6,10 @@ import pytest
 pytestmark = pytest.mark.pytest
 
 from byteb4rb1e.testing.pytest.decorators import run_in_subprocess_once
-from byteb4rb1e.testing.pytest.fixtures import current_test, mock_pkg
+from byteb4rb1e.testing.pytest.fixtures import (
+    current_test,
+    mock_system_site_package_dir
+)
 
 
 def test_current_test(current_test):
@@ -19,14 +22,16 @@ def test_current_test(current_test):
 
 
 @run_in_subprocess_once()
-def test_mock_pkg(mock_pkg):
+def test_mock_system_site_package_dir(mock_system_site_package_dir):
     """
     """
     dummy_data = 'Hello'
 
-    mock_pkg('foobarpkg', {
+    pkgdir = mock_system_site_package_dir('foobarpkg')
-        'data.txt': dummy_data
+
-    })
+    (pkgdir / 'data.txt').write_text(dummy_data)
+
+    assert (pkgdir / '__init__.py').exists()
 
     result = next(importlib.resources.files('foobarpkg').glob('data.txt')).read_text()