Add plugin loader test (ansible#411)

.github/workflows/tox.yml

@@ -50,7 +50,7 @@ jobs:
       matrix: ${{ fromJson(needs.prepare.outputs.matrix) }}
     env:
       FORCE_COLOR: 1
-      PYTEST_REQPASS: 108
+      PYTEST_REQPASS: 109
     steps:
       - uses: actions/checkout@v4
         with:

test/test_runtime.py

@@ -15,6 +15,8 @@
 import pytest
 from packaging.version import Version
 
+from ansible.plugins.loader import module_loader
+
 from ansible_compat.constants import INVALID_PREREQUISITES_RC
 from ansible_compat.errors import (
     AnsibleCommandError,
@@ -742,6 +744,42 @@ def test_install_collection_from_disk(
         runtime.clean()
 
 
+@pytest.mark.parametrize(
+    ("path", "expected_plugins"),
+    (
+        pytest.param(
+            "test/collections/acme.goodies",
+            [
+                "ansible.posix.patch",  # from tests/requirements.yml
+                "community.crypto.acme_account",  # from galaxy.yml as a git dependency
+            ],
+            id="modules",
+        ),
+    ),
+)
+def test_load_plugins(
+    path: str,
+    expected_plugins: list[str],
+) -> None:
+    """Tests ability to load plugin from a collection installed by requirement."""
+    with cwd(Path(path)):
+        from ansible_compat.prerun import get_cache_dir
+        rmtree(get_cache_dir(Path.cwd()), ignore_errors=True)
+        runtime = Runtime(isolated=True, require_module=True)
+        runtime.prepare_environment(install_local=True)
+        for plugin_name in expected_plugins:
+            loaded_module = module_loader.find_plugin_with_context(
+                plugin_name,
+                ignore_deprecated=True,
+                check_aliases=True,
+            )
+            assert (
+                loaded_module.resolved_fqcn is not None
+            ), f"Unable to load module {plugin_name}"
+
+        runtime.clean()
+
+
 def test_install_collection_from_disk_fail() -> None:
     """Tests that we fail to install a broken collection."""
     with cwd(Path("test/collections/acme.broken")):