test: add unit tests for core, parser and operations

tests/test_executor.py

@@ -0,0 +1,24 @@
+from __future__ import annotations
+
+from sshctl.operations.executor import ExecResult
+
+
+def test_exec_result_dataclass() -> None:
+    r = ExecResult(alias="server1", returncode=0, stdout="ok", stderr="")
+    assert r.alias == "server1"
+    assert r.returncode == 0
+    assert r.stdout == "ok"
+    assert r.error == ""
+
+
+def test_exec_result_error() -> None:
+    r = ExecResult(alias="server1", returncode=None, error="Timeout")
+    assert r.returncode is None
+    assert r.error == "Timeout"
+
+
+def test_exec_result_defaults() -> None:
+    r = ExecResult(alias="test", returncode=0)
+    assert r.stdout == ""
+    assert r.stderr == ""
+    assert r.error == ""