Add Hoyolab API integration

tests/test_hoyolab_api.py

@@ -0,0 +1,39 @@
+from __future__ import annotations
+
+from discord_rss_bot.hoyolab_api import extract_post_id_from_hoyolab_url
+
+
+class TestExtractPostIdFromHoyolabUrl:
+    def test_extract_post_id_from_article_url(self) -> None:
+        """Test extracting post ID from a direct article URL."""
+        test_cases: list[str] = [
+            "https://www.hoyolab.com/article/38588239",
+            "http://hoyolab.com/article/12345",
+            "https://www.hoyolab.com/article/987654321/comments",
+        ]
+
+        expected_ids: list[str] = ["38588239", "12345", "987654321"]
+
+        for url, expected_id in zip(test_cases, expected_ids, strict=False):
+            assert extract_post_id_from_hoyolab_url(url) == expected_id
+
+    def test_url_without_post_id(self) -> None:
+        """Test with a URL that doesn't have a post ID."""
+        test_cases: list[str] = [
+            "https://www.hoyolab.com/community",
+        ]
+
+        for url in test_cases:
+            assert extract_post_id_from_hoyolab_url(url) is None
+
+    def test_edge_cases(self) -> None:
+        """Test edge cases like None, empty string, and malformed URLs."""
+        test_cases: list[str | None] = [
+            None,
+            "",
+            "not_a_url",
+            "http:/",  # Malformed URL
+        ]
+
+        for url in test_cases:
+            assert extract_post_id_from_hoyolab_url(url) is None  # type: ignore