Test for circular imports in project (#779)

Test for circular imports in project

Resolves: #778
Test for circular imports in all local packages and modules.
This ensures all internal packages can be imported right away without any need to import some other module before doing so.
Related: #777

Reviewed-by: Sviatoslav Sydorenko <webknjaz+github/profile@redhat.com>
Reviewed-by: None <None>
Reviewed-by: Sorin Sbarnea <sorin.sbarnea@gmail.com>
Reviewed-by: Bradley A. Thornton <bthornto@redhat.com>

tests/unit/test_circular_imports.py

@@ -0,0 +1,95 @@
+"""Tests for circular imports in all local packages and modules.
+
+This ensures all internal packages can be imported right away without
+any need to import some other module before doing so.
+
+This module is based on an idea that pytest uses for self-testing:
+* https://github.com/sanitizers/octomachinery/blob/be18b54/tests/circular_imports_test.py
+* https://github.com/pytest-dev/pytest/blob/d18c75b/testing/test_meta.py
+* https://twitter.com/codewithanthony/status/1229445110510735361
+* https://github.com/aio-libs/aiohttp/blob/master/tests/test_circular_imports.py
+"""  # noqa: E501
+import os
+import pkgutil
+import subprocess
+import sys
+from itertools import chain
+from pathlib import Path
+from types import ModuleType
+from typing import Generator
+from typing import List
+
+import pytest
+
+import ansible_navigator
+
+
+def _find_all_importables(pkg: ModuleType) -> List[str]:
+    """Find all importables in the project.
+
+    Return them in order.
+    """
+    return sorted(
+        set(
+            chain.from_iterable(
+                _discover_path_importables(Path(p), pkg.__name__)
+                for p in pkg.__path__  # type: ignore[attr-defined]
+            ),
+        ),
+    )
+
+
+def _discover_path_importables(
+    pkg_pth: Path,
+    pkg_name: str,
+) -> Generator[str, None, None]:
+    """Yield all importables under a given path and package."""
+    for dir_path, _d, file_names in os.walk(pkg_pth):
+        pkg_dir_path = Path(dir_path)
+
+        if pkg_dir_path.parts[-1] == "__pycache__":
+            continue
+
+        if all(Path(_).suffix != ".py" for _ in file_names):
+            continue
+
+        rel_pt = pkg_dir_path.relative_to(pkg_pth)
+        pkg_pref = ".".join((pkg_name,) + rel_pt.parts)
+        yield from (
+            pkg_path
+            for _, pkg_path, _ in pkgutil.walk_packages(
+                (str(pkg_dir_path),),
+                prefix=f"{pkg_pref}.",
+            )
+        )
+
+
+@pytest.mark.parametrize(
+    "import_path",
+    _find_all_importables(ansible_navigator),
+)
+def test_no_warnings(import_path: str) -> None:
+    """Verify that exploding importables doesn't explode.
+
+    This is seeking for any import errors including ones caused
+    by circular imports.
+
+    DeprecationWarnings related to distutils in ansible_runner are ignored
+    """
+    imp_cmd = (
+        sys.executable,
+        "-W",
+        "error",
+        # NOTE: This exclusion is only necessary because ansible-runner still uses `distutils`
+        # NOTE: but this project already aims to target Python 3.10 as well.
+        # TODO: Remove this exclusion once the runner issue is addressed.
+        # Ref: https://github.com/ansible/ansible-runner/issues/969
+        "-W",
+        "ignore:The distutils package is deprecated and slated for removal in Python 3.12."
+        " Use setuptools or check PEP 632 for potential alternatives:DeprecationWarning:"
+        "ansible_runner.config.runner",
+        "-c",
+        f"import {import_path!s}",
+    )
+
+    subprocess.check_call(imp_cmd)