implement heartbeat command

tests/test_execute.py

@@ -0,0 +1,100 @@
+import subprocess
+
+from nexus_sync.client.execute import execute_command
+from nexus_sync.common import Command, CommandKind, CommandResultStatus
+
+
+def _command(name: str = "hostname", timeout_seconds: int = 30) -> Command:
+    return Command(
+        id="cmd_01JY3H8V8W8P3FXDR3S2BM7M6B",
+        kind=CommandKind.EXEC,
+        name=name,
+        args={},
+        timeout_seconds=timeout_seconds,
+    )
+
+
+def test_execute_command_runs_known_preset_without_shell(monkeypatch) -> None:
+    calls = []
+
+    def fake_run(argv, **kwargs):
+        calls.append((argv, kwargs))
+        return subprocess.CompletedProcess(argv, 0, stdout="host\n", stderr="")
+
+    monkeypatch.setattr(subprocess, "run", fake_run)
+
+    result = execute_command(_command())
+
+    assert result.status == CommandResultStatus.SUCCEEDED
+    assert result.return_code == 0
+    assert result.stdout == "host\n"
+    assert calls == [
+        (
+            ["hostname"],
+            {
+                "input": None,
+                "text": True,
+                "capture_output": True,
+                "timeout": 30,
+                "shell": False,
+                "check": False,
+            },
+        )
+    ]
+
+
+def test_execute_command_rejects_unknown_preset() -> None:
+    result = execute_command(_command(name="rm_everything"))
+
+    assert result.status == CommandResultStatus.REJECTED
+    assert result.return_code is None
+    assert "unknown command preset" in result.stderr
+
+
+def test_execute_command_maps_non_zero_exit_to_failed(monkeypatch) -> None:
+    def fake_run(argv, **kwargs):
+        return subprocess.CompletedProcess(argv, 2, stdout="", stderr="failed\n")
+
+    monkeypatch.setattr(subprocess, "run", fake_run)
+
+    result = execute_command(_command())
+
+    assert result.status == CommandResultStatus.FAILED
+    assert result.return_code == 2
+    assert result.stderr == "failed\n"
+
+
+def test_execute_command_maps_timeout(monkeypatch) -> None:
+    def fake_run(argv, **kwargs):
+        raise subprocess.TimeoutExpired(argv, timeout=kwargs["timeout"], output="partial")
+
+    monkeypatch.setattr(subprocess, "run", fake_run)
+
+    result = execute_command(_command(timeout_seconds=1))
+
+    assert result.status == CommandResultStatus.TIMED_OUT
+    assert result.return_code is None
+    assert result.started_at is not None
+    assert result.finished_at is not None
+
+
+def test_execute_command_truncates_output(monkeypatch) -> None:
+    def fake_run(argv, **kwargs):
+        return subprocess.CompletedProcess(argv, 0, stdout="abcdefghijklmnopqrstuvwxyz", stderr="")
+
+    monkeypatch.setattr(subprocess, "run", fake_run)
+
+    result = execute_command(_command(), output_limit_bytes=20)
+
+    assert result.stdout.endswith("\n[truncated]")
+    assert len(result.stdout.encode()) <= 20
+
+
+def test_execute_command_rejects_preset_validation_error() -> None:
+    command = _command()
+    invalid = command.model_copy(update={"args": {"unexpected": True}})
+
+    result = execute_command(invalid)
+
+    assert result.status == CommandResultStatus.REJECTED
+    assert "does not accept arguments" in result.stderr