tests: Add back missing fixtures

Author: pawamoy

tests/conftest.py

@@ -1 +1,80 @@
 """Configuration for the pytest test suite."""
+
+from collections import ChainMap
+
+import pytest
+from markdown.core import Markdown
+from mkdocs import config
+
+try:
+    from mkdocs.config.defaults import get_schema
+except ImportError:
+
+    def get_schema():  # noqa: WPS440
+        """Fallback for old versions of MkDocs."""  # noqa: DAR201
+        return config.DEFAULT_SCHEMA
+
+
+@pytest.fixture(name="mkdocs_conf")
+def fixture_mkdocs_conf(request, tmp_path):
+    """Yield a MkDocs configuration object.
+
+    Parameters:
+        request: Pytest request fixture.
+        tmp_path: Pytest temporary path fixture.
+
+    Yields:
+        MkDocs configuration object.
+    """
+    conf = config.Config(schema=get_schema())
+    while hasattr(request, "_parent_request") and hasattr(request._parent_request, "_parent_request"):  # noqa: WPS437
+        request = request._parent_request  # noqa: WPS437
+
+    conf_dict = {
+        "site_name": "foo",
+        "site_url": "https://example.org/",
+        "site_dir": str(tmp_path),
+        "plugins": [{"mkdocstrings": {"default_handler": "python"}}],
+        **getattr(request, "param", {}),
+    }
+    # Re-create it manually as a workaround for https://github.com/mkdocs/mkdocs/issues/2289
+    mdx_configs = dict(ChainMap(*conf_dict.get("markdown_extensions", [])))
+
+    conf.load_dict(conf_dict)
+    assert conf.validate() == ([], [])
+
+    conf["mdx_configs"] = mdx_configs
+    conf["markdown_extensions"].insert(0, "toc")  # Guaranteed to be added by MkDocs.
+
+    conf = conf["plugins"]["mkdocstrings"].on_config(conf)
+    conf = conf["plugins"]["autorefs"].on_config(conf)
+    yield conf
+    conf["plugins"]["mkdocstrings"].on_post_build(conf)
+
+
+@pytest.fixture(name="plugin")
+def fixture_plugin(mkdocs_conf):
+    """Return a plugin instance.
+
+    Parameters:
+        mkdocs_conf: MkDocs configuration object (fixture).
+
+    Returns:
+        Configurated plugin instance.
+    """
+    plugin = mkdocs_conf["plugins"]["mkdocstrings"]
+    plugin.md = Markdown(extensions=mkdocs_conf["markdown_extensions"], extension_configs=mkdocs_conf["mdx_configs"])
+    return plugin
+
+
+@pytest.fixture(name="ext_markdown")
+def fixture_ext_markdown(plugin):
+    """Return a Markdown instance with MkdocstringsExtension.
+
+    Parameters:
+        plugin: A configurated plugin instance. (fixture).
+
+    Returns:
+        The plugin Markdown instance.
+    """
+    return plugin.md