test+ci: add regression tests and GitHub Actions workflow

tests/test_config_normalization.py

@@ -0,0 +1,35 @@
+from __future__ import annotations
+
+from pathlib import Path
+
+from twitter_cli.config import load_config
+
+
+def test_filter_normalization_for_invalid_values(tmp_path: Path) -> None:
+    config_file = tmp_path / "config.yaml"
+    config_file.write_text(
+        "\n".join(
+            [
+                "fetch:",
+                "  count: -5",
+                "filter:",
+                "  mode: unknown",
+                "  topN: -1",
+                "  minScore: abc",
+                "  lang: zh",
+                "  weights:",
+                "    likes: bad",
+                "    retweets: 4",
+            ]
+        ),
+        encoding="utf-8",
+    )
+
+    config = load_config(str(config_file))
+    assert config["fetch"]["count"] == 1
+    assert config["filter"]["mode"] == "topN"
+    assert config["filter"]["topN"] == 1
+    assert config["filter"]["minScore"] == 50.0
+    assert config["filter"]["lang"] == []
+    assert config["filter"]["weights"]["likes"] == 1.0
+    assert config["filter"]["weights"]["retweets"] == 4.0