✅ increase test coverage

tests/unit/test_cli_error_paths.py

@@ -0,0 +1,142 @@
+from types import SimpleNamespace
+
+import pytest
+from click.testing import CliRunner
+
+from mysql_to_sqlite3.cli import cli as mysql2sqlite
+
+
+class _FakeConverter:
+    def __init__(self, *args, **kwargs):
+        pass
+
+    def transfer(self):
+        raise RuntimeError("should not run")
+
+
+def _fake_supported_charsets(charset=None):
+    """Produce deterministic charset/collation pairs for tests."""
+    # When called without a charset, emulate the public API generator used by click.Choice.
+    if charset is None:
+        return iter(
+            [
+                SimpleNamespace(id=0, charset="utf8mb4", collation="utf8mb4_general_ci"),
+                SimpleNamespace(id=1, charset="latin1", collation="latin1_swedish_ci"),
+            ]
+        )
+    # When scoped to a particular charset, expose only the primary collation.
+    return iter([SimpleNamespace(id=0, charset=charset, collation=f"{charset}_general_ci")])
+
+
+class TestCliErrorPaths:
+    def test_mysql_collation_must_match_charset(self, monkeypatch: pytest.MonkeyPatch) -> None:
+        """Invalid charset/collation combinations should be rejected before transfer starts."""
+        monkeypatch.setattr("mysql_to_sqlite3.cli.mysql_supported_character_sets", _fake_supported_charsets)
+        monkeypatch.setattr("mysql_to_sqlite3.cli.MySQLtoSQLite", _FakeConverter)
+
+        runner = CliRunner()
+        result = runner.invoke(
+            mysql2sqlite,
+            [
+                "-f",
+                "out.sqlite3",
+                "-d",
+                "db",
+                "-u",
+                "user",
+                "--mysql-charset",
+                "utf8mb4",
+                "--mysql-collation",
+                "latin1_swedish_ci",
+            ],
+        )
+        assert result.exit_code == 1
+        assert "Invalid value for '--collation'" in result.output
+
+    def test_debug_reraises_keyboard_interrupt(self, monkeypatch: pytest.MonkeyPatch) -> None:
+        """Debug mode should bubble up KeyboardInterrupt for easier debugging."""
+
+        class KeyboardInterruptConverter:
+            def __init__(self, *args, **kwargs):
+                pass
+
+            def transfer(self):
+                raise KeyboardInterrupt()
+
+        monkeypatch.setattr("mysql_to_sqlite3.cli.MySQLtoSQLite", KeyboardInterruptConverter)
+
+        kwargs = {
+            "sqlite_file": "out.sqlite3",
+            "mysql_user": "user",
+            "prompt_mysql_password": False,
+            "mysql_password": None,
+            "mysql_database": "db",
+            "mysql_tables": None,
+            "exclude_mysql_tables": None,
+            "mysql_views_as_tables": False,
+            "limit_rows": 0,
+            "collation": "BINARY",
+            "prefix_indices": False,
+            "without_foreign_keys": False,
+            "without_tables": False,
+            "without_data": False,
+            "strict": False,
+            "mysql_host": "localhost",
+            "mysql_port": 3306,
+            "mysql_charset": "utf8mb4",
+            "mysql_collation": None,
+            "skip_ssl": False,
+            "chunk": 200000,
+            "log_file": None,
+            "json_as_text": False,
+            "vacuum": False,
+            "use_buffered_cursors": False,
+            "quiet": False,
+            "debug": True,
+        }
+        with pytest.raises(KeyboardInterrupt):
+            mysql2sqlite.callback(**kwargs)
+
+    def test_debug_reraises_generic_exception(self, monkeypatch: pytest.MonkeyPatch) -> None:
+        """Debug mode should bubble up unexpected exceptions."""
+
+        class ExplodingConverter:
+            def __init__(self, *args, **kwargs):
+                pass
+
+            def transfer(self):
+                raise RuntimeError("boom")
+
+        monkeypatch.setattr("mysql_to_sqlite3.cli.MySQLtoSQLite", ExplodingConverter)
+
+        kwargs = {
+            "sqlite_file": "out.sqlite3",
+            "mysql_user": "user",
+            "prompt_mysql_password": False,
+            "mysql_password": None,
+            "mysql_database": "db",
+            "mysql_tables": None,
+            "exclude_mysql_tables": None,
+            "mysql_views_as_tables": False,
+            "limit_rows": 0,
+            "collation": "BINARY",
+            "prefix_indices": False,
+            "without_foreign_keys": False,
+            "without_tables": False,
+            "without_data": False,
+            "strict": False,
+            "mysql_host": "localhost",
+            "mysql_port": 3306,
+            "mysql_charset": "utf8mb4",
+            "mysql_collation": None,
+            "skip_ssl": False,
+            "chunk": 200000,
+            "log_file": None,
+            "json_as_text": False,
+            "vacuum": False,
+            "use_buffered_cursors": False,
+            "quiet": False,
+            "debug": True,
+        }
+        with pytest.raises(RuntimeError):
+            mysql2sqlite.callback(**kwargs)