[commands] Report error on C++ CommandPtr use-after-move (#4575)

wpilibNewCommands/src/test/native/cpp/frc2/command/CommandPtrTest.cpp

@@ -0,0 +1,35 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#include <frc/Errors.h>
+
+#include "CommandTestBase.h"
+#include "frc2/command/CommandPtr.h"
+#include "frc2/command/CommandScheduler.h"
+#include "frc2/command/Commands.h"
+
+using namespace frc2;
+class CommandPtrTest : public CommandTestBase {};
+
+TEST_F(CommandPtrTest, MovedFrom) {
+  CommandScheduler scheduler = GetScheduler();
+
+  int counter = 0;
+
+  CommandPtr movedFrom = cmd::Run([&counter] { counter++; });
+  CommandPtr movedTo = std::move(movedFrom);
+
+  EXPECT_NO_FATAL_FAILURE(scheduler.Schedule(movedTo));
+  EXPECT_NO_FATAL_FAILURE(scheduler.Run());
+
+  EXPECT_EQ(1, counter);
+  EXPECT_NO_FATAL_FAILURE(scheduler.Cancel(movedTo));
+
+  EXPECT_THROW(scheduler.Schedule(movedFrom), frc::RuntimeError);
+  EXPECT_THROW(movedFrom.IsScheduled(), frc::RuntimeError);
+  EXPECT_THROW(static_cast<void>(std::move(movedFrom).Repeatedly()),
+               frc::RuntimeError);
+
+  EXPECT_EQ(1, counter);
+}