[commands] Merge CommandBase into Command and SubsystemBase into Subsystem (#5392)

Moves all CommandBase functionality into Command and deprecates CommandBase for removal.
Moves all SubsystemBase functionality into Subsystem and deprecates SubsystemBase for removal.
Adds a function to CommandScheduler to remove all registered Subsystems.

wpilibNewCommands/src/main/native/cpp/frc2/command/Command.cpp

@@ -4,6 +4,9 @@
 
 #include "frc2/command/Command.h"
 
+#include <wpi/sendable/SendableBuilder.h>
+#include <wpi/sendable/SendableRegistry.h>
+
 #include "frc2/command/CommandHelper.h"
 #include "frc2/command/CommandScheduler.h"
 #include "frc2/command/ConditionalCommand.h"
@@ -19,6 +22,10 @@
 
 using namespace frc2;
 
+Command::Command() {
+  wpi::SendableRegistry::Add(this, GetTypeName(*this));
+}
+
 Command::~Command() {
   CommandScheduler::GetInstance().Cancel(this);
 }
@@ -32,6 +39,42 @@ void Command::Initialize() {}
 void Command::Execute() {}
 void Command::End(bool interrupted) {}
 
+wpi::SmallSet<Subsystem*, 4> Command::GetRequirements() const {
+  return m_requirements;
+}
+
+void Command::AddRequirements(std::initializer_list<Subsystem*> requirements) {
+  m_requirements.insert(requirements.begin(), requirements.end());
+}
+
+void Command::AddRequirements(std::span<Subsystem* const> requirements) {
+  m_requirements.insert(requirements.begin(), requirements.end());
+}
+
+void Command::AddRequirements(wpi::SmallSet<Subsystem*, 4> requirements) {
+  m_requirements.insert(requirements.begin(), requirements.end());
+}
+
+void Command::AddRequirements(Subsystem* requirement) {
+  m_requirements.insert(requirement);
+}
+
+void Command::SetName(std::string_view name) {
+  wpi::SendableRegistry::SetName(this, name);
+}
+
+std::string Command::GetName() const {
+  return wpi::SendableRegistry::GetName(this);
+}
+
+std::string Command::GetSubsystem() const {
+  return wpi::SendableRegistry::GetSubsystem(this);
+}
+
+void Command::SetSubsystem(std::string_view subsystem) {
+  wpi::SendableRegistry::SetSubsystem(this, subsystem);
+}
+
 CommandPtr Command::WithTimeout(units::second_t duration) && {
   return std::move(*this).ToPtr().WithTimeout(duration);
 }
@@ -125,12 +168,6 @@ bool Command::HasRequirement(Subsystem* requirement) const {
   return hasRequirement;
 }
 
-std::string Command::GetName() const {
-  return GetTypeName(*this);
-}
-
-void Command::SetName(std::string_view name) {}
-
 bool Command::IsComposed() const {
   return m_isComposed;
 }
@@ -139,6 +176,39 @@ void Command::SetComposed(bool isComposed) {
   m_isComposed = isComposed;
 }
 
+void Command::InitSendable(wpi::SendableBuilder& builder) {
+  builder.SetSmartDashboardType("Command");
+  builder.AddStringProperty(
+      ".name", [this] { return GetName(); }, nullptr);
+  builder.AddBooleanProperty(
+      "running", [this] { return IsScheduled(); },
+      [this](bool value) {
+        bool isScheduled = IsScheduled();
+        if (value && !isScheduled) {
+          Schedule();
+        } else if (!value && isScheduled) {
+          Cancel();
+        }
+      });
+  builder.AddBooleanProperty(
+      ".isParented", [this] { return IsComposed(); }, nullptr);
+  builder.AddStringProperty(
+      "interruptBehavior",
+      [this] {
+        switch (GetInterruptionBehavior()) {
+          case Command::InterruptionBehavior::kCancelIncoming:
+            return "kCancelIncoming";
+          case Command::InterruptionBehavior::kCancelSelf:
+            return "kCancelSelf";
+          default:
+            return "Invalid";
+        }
+      },
+      nullptr);
+  builder.AddBooleanProperty(
+      "runsWhenDisabled", [this] { return RunsWhenDisabled(); }, nullptr);
+}
+
 namespace frc2 {
 bool RequirementsDisjoint(Command* first, Command* second) {
   bool disjoint = true;

wpilibNewCommands/src/main/native/cpp/frc2/command/CommandBase.cpp

@@ -3,82 +3,3 @@
 // the WPILib BSD license file in the root directory of this project.
 
 #include "frc2/command/CommandBase.h"
-
-#include <wpi/sendable/SendableBuilder.h>
-#include <wpi/sendable/SendableRegistry.h>
-
-using namespace frc2;
-
-CommandBase::CommandBase() {
-  wpi::SendableRegistry::Add(this, GetTypeName(*this));
-}
-
-void CommandBase::AddRequirements(
-    std::initializer_list<Subsystem*> requirements) {
-  m_requirements.insert(requirements.begin(), requirements.end());
-}
-
-void CommandBase::AddRequirements(std::span<Subsystem* const> requirements) {
-  m_requirements.insert(requirements.begin(), requirements.end());
-}
-
-void CommandBase::AddRequirements(wpi::SmallSet<Subsystem*, 4> requirements) {
-  m_requirements.insert(requirements.begin(), requirements.end());
-}
-
-void CommandBase::AddRequirements(Subsystem* requirement) {
-  m_requirements.insert(requirement);
-}
-
-wpi::SmallSet<Subsystem*, 4> CommandBase::GetRequirements() const {
-  return m_requirements;
-}
-
-void CommandBase::SetName(std::string_view name) {
-  wpi::SendableRegistry::SetName(this, name);
-}
-
-std::string CommandBase::GetName() const {
-  return wpi::SendableRegistry::GetName(this);
-}
-
-std::string CommandBase::GetSubsystem() const {
-  return wpi::SendableRegistry::GetSubsystem(this);
-}
-
-void CommandBase::SetSubsystem(std::string_view subsystem) {
-  wpi::SendableRegistry::SetSubsystem(this, subsystem);
-}
-
-void CommandBase::InitSendable(wpi::SendableBuilder& builder) {
-  builder.SetSmartDashboardType("Command");
-  builder.AddStringProperty(
-      ".name", [this] { return GetName(); }, nullptr);
-  builder.AddBooleanProperty(
-      "running", [this] { return IsScheduled(); },
-      [this](bool value) {
-        bool isScheduled = IsScheduled();
-        if (value && !isScheduled) {
-          Schedule();
-        } else if (!value && isScheduled) {
-          Cancel();
-        }
-      });
-  builder.AddBooleanProperty(
-      ".isParented", [this] { return IsComposed(); }, nullptr);
-  builder.AddStringProperty(
-      "interruptBehavior",
-      [this] {
-        switch (GetInterruptionBehavior()) {
-          case Command::InterruptionBehavior::kCancelIncoming:
-            return "kCancelIncoming";
-          case Command::InterruptionBehavior::kCancelSelf:
-            return "kCancelSelf";
-          default:
-            return "Invalid";
-        }
-      },
-      nullptr);
-  builder.AddBooleanProperty(
-      "runsWhenDisabled", [this] { return RunsWhenDisabled(); }, nullptr);
-}

wpilibNewCommands/src/main/native/cpp/frc2/command/CommandPtr.cpp

@@ -236,12 +236,12 @@ CommandPtr CommandPtr::WithName(std::string_view name) && {
   return std::move(wrapper).ToPtr();
 }
 
-CommandBase* CommandPtr::get() const& {
+Command* CommandPtr::get() const& {
   AssertValid();
   return m_ptr.get();
 }
 
-std::unique_ptr<CommandBase> CommandPtr::Unwrap() && {
+std::unique_ptr<Command> CommandPtr::Unwrap() && {
   AssertValid();
   return std::move(m_ptr);
 }

wpilibNewCommands/src/main/native/cpp/frc2/command/CommandScheduler.cpp

@@ -291,6 +291,10 @@ void CommandScheduler::UnregisterSubsystem(
   }
 }
 
+void CommandScheduler::UnregisterAllSubsystems() {
+  m_impl->subsystems.clear();
+}
+
 void CommandScheduler::SetDefaultCommand(Subsystem* subsystem,
                                          CommandPtr&& defaultCommand) {
   if (!defaultCommand.get()->HasRequirement(subsystem)) {

wpilibNewCommands/src/main/native/cpp/frc2/command/ConditionalCommand.cpp

@@ -66,7 +66,7 @@ Command::InterruptionBehavior ConditionalCommand::GetInterruptionBehavior()
 }
 
 void ConditionalCommand::InitSendable(wpi::SendableBuilder& builder) {
-  CommandBase::InitSendable(builder);
+  Command::InitSendable(builder);
   builder.AddStringProperty(
       "onTrue", [this] { return m_onTrue->GetName(); }, nullptr);
   builder.AddStringProperty(

wpilibNewCommands/src/main/native/cpp/frc2/command/ParallelDeadlineGroup.cpp

@@ -97,7 +97,7 @@ void ParallelDeadlineGroup::SetDeadline(std::unique_ptr<Command>&& deadline) {
 }
 
 void ParallelDeadlineGroup::InitSendable(wpi::SendableBuilder& builder) {
-  CommandBase::InitSendable(builder);
+  Command::InitSendable(builder);
 
   builder.AddStringProperty(
       "deadline", [this] { return m_deadline->GetName(); }, nullptr);

wpilibNewCommands/src/main/native/cpp/frc2/command/ProxyCommand.cpp

@@ -41,7 +41,7 @@ bool ProxyCommand::IsFinished() {
 }
 
 void ProxyCommand::InitSendable(wpi::SendableBuilder& builder) {
-  CommandBase::InitSendable(builder);
+  Command::InitSendable(builder);
   builder.AddStringProperty(
       "proxied",
       [this] {

wpilibNewCommands/src/main/native/cpp/frc2/command/RamseteCommand.cpp

@@ -161,7 +161,7 @@ bool RamseteCommand::IsFinished() {
 }
 
 void RamseteCommand::InitSendable(wpi::SendableBuilder& builder) {
-  CommandBase::InitSendable(builder);
+  Command::InitSendable(builder);
   builder.AddDoubleProperty(
       "leftVelocity", [this] { return m_prevSpeeds.left.value(); }, nullptr);
   builder.AddDoubleProperty(

wpilibNewCommands/src/main/native/cpp/frc2/command/RepeatCommand.cpp

@@ -56,7 +56,7 @@ Command::InterruptionBehavior RepeatCommand::GetInterruptionBehavior() const {
 }
 
 void RepeatCommand::InitSendable(wpi::SendableBuilder& builder) {
-  CommandBase::InitSendable(builder);
+  Command::InitSendable(builder);
   builder.AddStringProperty(
       "command", [this] { return m_command->GetName(); }, nullptr);
 }

wpilibNewCommands/src/main/native/cpp/frc2/command/SequentialCommandGroup.cpp

@@ -83,7 +83,7 @@ void SequentialCommandGroup::AddCommands(
 }
 
 void SequentialCommandGroup::InitSendable(wpi::SendableBuilder& builder) {
-  CommandBase::InitSendable(builder);
+  Command::InitSendable(builder);
   builder.AddIntegerProperty(
       "index", [this] { return m_currentCommandIndex; }, nullptr);
 }

wpilibNewCommands/src/main/native/cpp/frc2/command/Subsystem.cpp

@@ -8,6 +8,12 @@
 #include "frc2/command/Commands.h"
 
 using namespace frc2;
+
+Subsystem::Subsystem() {
+  wpi::SendableRegistry::AddLW(this, GetTypeName(*this));
+  CommandScheduler::GetInstance().RegisterSubsystem({this});
+}
+
 Subsystem::~Subsystem() {
   CommandScheduler::GetInstance().UnregisterSubsystem(this);
 }
@@ -33,6 +39,26 @@ Command* Subsystem::GetCurrentCommand() const {
   return CommandScheduler::GetInstance().Requiring(this);
 }
 
+std::string Subsystem::GetName() const {
+  return wpi::SendableRegistry::GetName(this);
+}
+
+void Subsystem::SetName(std::string_view name) {
+  wpi::SendableRegistry::SetName(this, name);
+}
+
+std::string Subsystem::GetSubsystem() const {
+  return wpi::SendableRegistry::GetSubsystem(this);
+}
+
+void Subsystem::SetSubsystem(std::string_view name) {
+  wpi::SendableRegistry::SetSubsystem(this, name);
+}
+
+void Subsystem::AddChild(std::string name, wpi::Sendable* child) {
+  wpi::SendableRegistry::AddLW(child, GetSubsystem(), name);
+}
+
 void Subsystem::Register() {
   return CommandScheduler::GetInstance().RegisterSubsystem(this);
 }
@@ -54,3 +80,33 @@ CommandPtr Subsystem::RunEnd(std::function<void()> run,
                              std::function<void()> end) {
   return cmd::RunEnd(std::move(run), std::move(end), {this});
 }
+
+void Subsystem::InitSendable(wpi::SendableBuilder& builder) {
+  builder.SetSmartDashboardType("Subsystem");
+  builder.AddBooleanProperty(
+      ".hasDefault", [this] { return GetDefaultCommand() != nullptr; },
+      nullptr);
+  builder.AddStringProperty(
+      ".default",
+      [this]() -> std::string {
+        auto command = GetDefaultCommand();
+        if (command == nullptr) {
+          return "none";
+        }
+        return command->GetName();
+      },
+      nullptr);
+  builder.AddBooleanProperty(
+      ".hasCommand", [this] { return GetCurrentCommand() != nullptr; },
+      nullptr);
+  builder.AddStringProperty(
+      ".command",
+      [this]() -> std::string {
+        auto command = GetCurrentCommand();
+        if (command == nullptr) {
+          return "none";
+        }
+        return command->GetName();
+      },
+      nullptr);
+}

wpilibNewCommands/src/main/native/cpp/frc2/command/SubsystemBase.cpp

@@ -12,57 +12,4 @@
 
 using namespace frc2;
 
-SubsystemBase::SubsystemBase() {
-  wpi::SendableRegistry::AddLW(this, GetTypeName(*this));
-  CommandScheduler::GetInstance().RegisterSubsystem({this});
-}
-
-void SubsystemBase::InitSendable(wpi::SendableBuilder& builder) {
-  builder.SetSmartDashboardType("Subsystem");
-  builder.AddBooleanProperty(
-      ".hasDefault", [this] { return GetDefaultCommand() != nullptr; },
-      nullptr);
-  builder.AddStringProperty(
-      ".default",
-      [this]() -> std::string {
-        auto command = GetDefaultCommand();
-        if (command == nullptr) {
-          return "none";
-        }
-        return command->GetName();
-      },
-      nullptr);
-  builder.AddBooleanProperty(
-      ".hasCommand", [this] { return GetCurrentCommand() != nullptr; },
-      nullptr);
-  builder.AddStringProperty(
-      ".command",
-      [this]() -> std::string {
-        auto command = GetCurrentCommand();
-        if (command == nullptr) {
-          return "none";
-        }
-        return command->GetName();
-      },
-      nullptr);
-}
-
-std::string SubsystemBase::GetName() const {
-  return wpi::SendableRegistry::GetName(this);
-}
-
-void SubsystemBase::SetName(std::string_view name) {
-  wpi::SendableRegistry::SetName(this, name);
-}
-
-std::string SubsystemBase::GetSubsystem() const {
-  return wpi::SendableRegistry::GetSubsystem(this);
-}
-
-void SubsystemBase::SetSubsystem(std::string_view name) {
-  wpi::SendableRegistry::SetSubsystem(this, name);
-}
-
-void SubsystemBase::AddChild(std::string name, wpi::Sendable* child) {
-  wpi::SendableRegistry::AddLW(child, GetSubsystem(), name);
-}
+SubsystemBase::SubsystemBase() {}

wpilibNewCommands/src/main/native/cpp/frc2/command/WaitCommand.cpp

@@ -30,7 +30,7 @@ bool WaitCommand::RunsWhenDisabled() const {
 }
 
 void WaitCommand::InitSendable(wpi::SendableBuilder& builder) {
-  CommandBase::InitSendable(builder);
+  Command::InitSendable(builder);
   builder.AddDoubleProperty(
       "duration", [this] { return m_duration.value(); }, nullptr);
 }

wpilibNewCommands/src/main/native/include/frc2/command/Command.h

@@ -13,6 +13,7 @@
 #include <units/time.h>
 #include <wpi/Demangle.h>
 #include <wpi/SmallSet.h>
+#include <wpi/sendable/Sendable.h>
 
 #include "frc2/command/Subsystem.h"
 
@@ -41,10 +42,9 @@ std::string GetTypeName(const T& type) {
  * @see CommandScheduler
  * @see CommandHelper
  */
-class Command {
+class Command : public wpi::Sendable, public wpi::SendableHelper<Command> {
  public:
-  Command() = default;
-  virtual ~Command();
+  ~Command() override;
 
   Command(const Command&) = default;
   Command& operator=(const Command& rhs);
@@ -92,7 +92,91 @@ class Command {
    * @return the set of subsystems that are required
    * @see InterruptionBehavior
    */
-  virtual wpi::SmallSet<Subsystem*, 4> GetRequirements() const = 0;
+  virtual wpi::SmallSet<Subsystem*, 4> GetRequirements() const;
+
+  /**
+   * Adds the specified Subsystem requirements to the command.
+   *
+   * The scheduler will prevent two commands that require the same subsystem
+   * from being scheduled simultaneously.
+   *
+   * Note that the scheduler determines the requirements of a command when it
+   * is scheduled, so this method should normally be called from the command's
+   * constructor.
+   *
+   * @param requirements the Subsystem requirements to add
+   */
+  void AddRequirements(std::initializer_list<Subsystem*> requirements);
+
+  /**
+   * Adds the specified Subsystem requirements to the command.
+   *
+   * The scheduler will prevent two commands that require the same subsystem
+   * from being scheduled simultaneously.
+   *
+   * Note that the scheduler determines the requirements of a command when it
+   * is scheduled, so this method should normally be called from the command's
+   * constructor.
+   *
+   * @param requirements the Subsystem requirements to add
+   */
+  void AddRequirements(std::span<Subsystem* const> requirements);
+
+  /**
+   * Adds the specified Subsystem requirements to the command.
+   *
+   * The scheduler will prevent two commands that require the same subsystem
+   * from being scheduled simultaneously.
+   *
+   * Note that the scheduler determines the requirements of a command when it
+   * is scheduled, so this method should normally be called from the command's
+   * constructor.
+   *
+   * @param requirements the Subsystem requirements to add
+   */
+  void AddRequirements(wpi::SmallSet<Subsystem*, 4> requirements);
+
+  /**
+   * Adds the specified Subsystem requirement to the command.
+   *
+   * The scheduler will prevent two commands that require the same subsystem
+   * from being scheduled simultaneously.
+   *
+   * Note that the scheduler determines the requirements of a command when it
+   * is scheduled, so this method should normally be called from the command's
+   * constructor.
+   *
+   * @param requirement the Subsystem requirement to add
+   */
+  void AddRequirements(Subsystem* requirement);
+
+  /**
+   * Gets the name of this Command.
+   *
+   * @return Name
+   */
+  std::string GetName() const;
+
+  /**
+   * Sets the name of this Command.
+   *
+   * @param name name
+   */
+  void SetName(std::string_view name);
+
+  /**
+   * Gets the subsystem name of this Command.
+   *
+   * @return Subsystem name
+   */
+  std::string GetSubsystem() const;
+
+  /**
+   * Sets the subsystem name of this Command.
+   *
+   * @param subsystem subsystem name
+   */
+  void SetSubsystem(std::string_view subsystem);
 
   /**
    * An enum describing the command's behavior when another command with a
@@ -345,28 +429,19 @@ class Command {
     return InterruptionBehavior::kCancelSelf;
   }
 
-  /**
-   * Gets the name of this Command. Defaults to the simple class name if not
-   * overridden.
-   *
-   * @return The display name of the Command
-   */
-  virtual std::string GetName() const;
-
-  /**
-   * Sets the name of this Command. Nullop if not overridden.
-   *
-   * @param name The display name of the Command.
-   */
-  virtual void SetName(std::string_view name);
-
   /**
    * Transfers ownership of this command to a unique pointer.  Used for
    * decorator methods.
    */
   virtual CommandPtr ToPtr() && = 0;
 
+  void InitSendable(wpi::SendableBuilder& builder) override;
+
  protected:
+  Command();
+
+  wpi::SmallSet<Subsystem*, 4> m_requirements;
+
   /**
    * Transfers ownership of this command to a unique pointer.  Used for
    * decorator methods.

wpilibNewCommands/src/main/native/include/frc2/command/CommandBase.h

@@ -4,14 +4,7 @@
 
 #pragma once
 
-#include <initializer_list>
-#include <span>
-#include <string>
-#include <string_view>
-
-#include <wpi/SmallSet.h>
-#include <wpi/sendable/Sendable.h>
-#include <wpi/sendable/SendableHelper.h>
+#include <wpi/deprecated.h>
 
 #include "frc2/command/Command.h"
 
@@ -20,106 +13,13 @@ namespace frc2 {
  * A Sendable base class for Commands.
  *
  * This class is provided by the NewCommands VendorDep
+ *
+ * @deprecated All functionality provided by CommandBase has been merged into
+ * Command. Use Command instead.
  */
-class CommandBase : public Command,
-                    public wpi::Sendable,
-                    public wpi::SendableHelper<CommandBase> {
- public:
-  /**
-   * Adds the specified Subsystem requirements to the command.
-   *
-   * The scheduler will prevent two commands that require the same subsystem
-   * from being scheduled simultaneously.
-   *
-   * Note that the scheduler determines the requirements of a command when it
-   * is scheduled, so this method should normally be called from the command's
-   * constructor.
-   *
-   * @param requirements the Subsystem requirements to add
-   */
-  void AddRequirements(std::initializer_list<Subsystem*> requirements);
-
-  /**
-   * Adds the specified Subsystem requirements to the command.
-   *
-   * The scheduler will prevent two commands that require the same subsystem
-   * from being scheduled simultaneously.
-   *
-   * Note that the scheduler determines the requirements of a command when it
-   * is scheduled, so this method should normally be called from the command's
-   * constructor.
-   *
-   * @param requirements the Subsystem requirements to add
-   */
-  void AddRequirements(std::span<Subsystem* const> requirements);
-
-  /**
-   * Adds the specified Subsystem requirements to the command.
-   *
-   * The scheduler will prevent two commands that require the same subsystem
-   * from being scheduled simultaneously.
-   *
-   * Note that the scheduler determines the requirements of a command when it
-   * is scheduled, so this method should normally be called from the command's
-   * constructor.
-   *
-   * @param requirements the Subsystem requirements to add
-   */
-  void AddRequirements(wpi::SmallSet<Subsystem*, 4> requirements);
-
-  /**
-   * Adds the specified Subsystem requirement to the command.
-   *
-   * The scheduler will prevent two commands that require the same subsystem
-   * from being scheduled simultaneously.
-   *
-   * Note that the scheduler determines the requirements of a command when it
-   * is scheduled, so this method should normally be called from the command's
-   * constructor.
-   *
-   * @param requirement the Subsystem requirement to add
-   */
-  void AddRequirements(Subsystem* requirement);
-
-  /**
-   * Gets the Subsystem requirements of the command.
-   *
-   * @return the Command's Subsystem requirements
-   */
-  wpi::SmallSet<Subsystem*, 4> GetRequirements() const override;
-
-  /**
-   * Sets the name of this Command.
-   *
-   * @param name name
-   */
-  void SetName(std::string_view name) override;
-
-  /**
-   * Gets the name of this Command.
-   *
-   * @return Name
-   */
-  std::string GetName() const override;
-
-  /**
-   * Gets the subsystem name of this Command.
-   *
-   * @return Subsystem name
-   */
-  std::string GetSubsystem() const;
-
-  /**
-   * Sets the subsystem name of this Command.
-   *
-   * @param subsystem subsystem name
-   */
-  void SetSubsystem(std::string_view subsystem);
-
-  void InitSendable(wpi::SendableBuilder& builder) override;
-
+class [[deprecated("Use Command instead")]] CommandBase : public Command {
  protected:
+  WPI_DEPRECATED("Use Command instead")
   CommandBase();
-  wpi::SmallSet<Subsystem*, 4> m_requirements;
 };
 }  // namespace frc2

wpilibNewCommands/src/main/native/include/frc2/command/CommandPtr.h

@@ -13,7 +13,7 @@
 #include <utility>
 #include <vector>
 
-#include "frc2/command/CommandBase.h"
+#include "frc2/command/Command.h"
 
 namespace frc2 {
 /**
@@ -28,7 +28,7 @@ namespace frc2 {
  */
 class CommandPtr final {
  public:
-  explicit CommandPtr(std::unique_ptr<CommandBase>&& command)
+  explicit CommandPtr(std::unique_ptr<Command>&& command)
       : m_ptr(std::move(command)) {}
 
   template <std::derived_from<Command> T>
@@ -269,15 +269,15 @@ class CommandPtr final {
   /**
    * Get a raw pointer to the held command.
    */
-  CommandBase* get() const&;
+  Command* get() const&;
 
   // Prevent calls on a temporary, as the returned pointer would be invalid
-  CommandBase* get() && = delete;
+  Command* get() && = delete;
 
   /**
    * Convert to the underlying unique_ptr.
    */
-  std::unique_ptr<CommandBase> Unwrap() &&;
+  std::unique_ptr<Command> Unwrap() &&;
 
   /**
    * Schedules this command.
@@ -336,7 +336,7 @@ class CommandPtr final {
       std::vector<CommandPtr>&& vec);
 
  private:
-  std::unique_ptr<CommandBase> m_ptr;
+  std::unique_ptr<Command> m_ptr;
   void AssertValid() const;
 };
 

wpilibNewCommands/src/main/native/include/frc2/command/CommandScheduler.h

@@ -158,6 +158,13 @@ class CommandScheduler final : public nt::NTSendable,
   void UnregisterSubsystem(std::initializer_list<Subsystem*> subsystems);
   void UnregisterSubsystem(std::span<Subsystem* const> subsystems);
 
+  /**
+   * Un-registers all registered Subsystems with the scheduler. All currently
+   * registered subsystems will no longer have their periodic block called, and
+   * will not have their default command scheduled.
+   */
+  void UnregisterAllSubsystems();
+
   /**
    * Sets the default command for a subsystem.  Registers that subsystem if it
    * is not already registered.  Default commands will run whenever there is no

wpilibNewCommands/src/main/native/include/frc2/command/ConditionalCommand.h

@@ -9,7 +9,7 @@
 #include <memory>
 #include <utility>
 
-#include "frc2/command/CommandBase.h"
+#include "frc2/command/Command.h"
 #include "frc2/command/CommandHelper.h"
 
 namespace frc2 {
@@ -26,8 +26,7 @@ namespace frc2 {
  *
  * @see ScheduleCommand
  */
-class ConditionalCommand
-    : public CommandHelper<CommandBase, ConditionalCommand> {
+class ConditionalCommand : public CommandHelper<Command, ConditionalCommand> {
  public:
   /**
    * Creates a new ConditionalCommand.

wpilibNewCommands/src/main/native/include/frc2/command/FunctionalCommand.h

@@ -8,7 +8,7 @@
 #include <initializer_list>
 #include <span>
 
-#include "frc2/command/CommandBase.h"
+#include "frc2/command/Command.h"
 #include "frc2/command/CommandHelper.h"
 
 namespace frc2 {
@@ -21,7 +21,7 @@ namespace frc2 {
  *
  * This class is provided by the NewCommands VendorDep
  */
-class FunctionalCommand : public CommandHelper<CommandBase, FunctionalCommand> {
+class FunctionalCommand : public CommandHelper<Command, FunctionalCommand> {
  public:
   /**
    * Creates a new FunctionalCommand.

wpilibNewCommands/src/main/native/include/frc2/command/MecanumControllerCommand.h

@@ -23,7 +23,7 @@
 #include <units/velocity.h>
 #include <units/voltage.h>
 
-#include "CommandBase.h"
+#include "Command.h"
 #include "CommandHelper.h"
 
 #pragma once
@@ -51,7 +51,7 @@ namespace frc2 {
  * This class is provided by the NewCommands VendorDep
  */
 class MecanumControllerCommand
-    : public CommandHelper<CommandBase, MecanumControllerCommand> {
+    : public CommandHelper<Command, MecanumControllerCommand> {
  public:
   /**
    * Constructs a new MecanumControllerCommand that when executed will follow

wpilibNewCommands/src/main/native/include/frc2/command/NotifierCommand.h

@@ -11,7 +11,7 @@
 #include <frc/Notifier.h>
 #include <units/time.h>
 
-#include "frc2/command/CommandBase.h"
+#include "frc2/command/Command.h"
 #include "frc2/command/CommandHelper.h"
 
 namespace frc2 {
@@ -27,7 +27,7 @@ namespace frc2 {
  *
  * This class is provided by the NewCommands VendorDep
  */
-class NotifierCommand : public CommandHelper<CommandBase, NotifierCommand> {
+class NotifierCommand : public CommandHelper<Command, NotifierCommand> {
  public:
   /**
    * Creates a new NotifierCommand.

wpilibNewCommands/src/main/native/include/frc2/command/PIDCommand.h

@@ -10,7 +10,7 @@
 
 #include <frc/controller/PIDController.h>
 
-#include "frc2/command/CommandBase.h"
+#include "frc2/command/Command.h"
 #include "frc2/command/CommandHelper.h"
 
 namespace frc2 {
@@ -24,7 +24,7 @@ namespace frc2 {
  *
  * @see PIDController
  */
-class PIDCommand : public CommandHelper<CommandBase, PIDCommand> {
+class PIDCommand : public CommandHelper<Command, PIDCommand> {
  public:
   /**
    * Creates a new PIDCommand, which controls the given output with a

wpilibNewCommands/src/main/native/include/frc2/command/PIDSubsystem.h

@@ -6,7 +6,7 @@
 
 #include <frc/controller/PIDController.h>
 
-#include "frc2/command/SubsystemBase.h"
+#include "frc2/command/Subsystem.h"
 
 namespace frc2 {
 /**
@@ -17,7 +17,7 @@ namespace frc2 {
  *
  * @see PIDController
  */
-class PIDSubsystem : public SubsystemBase {
+class PIDSubsystem : public Subsystem {
  public:
   /**
    * Creates a new PIDSubsystem.

wpilibNewCommands/src/main/native/include/frc2/command/ParallelCommandGroup.h

@@ -33,7 +33,7 @@ namespace frc2 {
  * This class is provided by the NewCommands VendorDep
  */
 class ParallelCommandGroup
-    : public CommandHelper<CommandBase, ParallelCommandGroup> {
+    : public CommandHelper<Command, ParallelCommandGroup> {
  public:
   /**
    * Creates a new ParallelCommandGroup. The given commands will be executed

wpilibNewCommands/src/main/native/include/frc2/command/ParallelDeadlineGroup.h

@@ -34,7 +34,7 @@ namespace frc2 {
  * This class is provided by the NewCommands VendorDep
  */
 class ParallelDeadlineGroup
-    : public CommandHelper<CommandBase, ParallelDeadlineGroup> {
+    : public CommandHelper<Command, ParallelDeadlineGroup> {
  public:
   /**
    * Creates a new ParallelDeadlineGroup. The given commands (including the

wpilibNewCommands/src/main/native/include/frc2/command/ParallelRaceGroup.h

@@ -32,7 +32,7 @@ namespace frc2 {
  *
  * This class is provided by the NewCommands VendorDep
  */
-class ParallelRaceGroup : public CommandHelper<CommandBase, ParallelRaceGroup> {
+class ParallelRaceGroup : public CommandHelper<Command, ParallelRaceGroup> {
  public:
   /**
    * Creates a new ParallelCommandRace. The given commands will be executed

wpilibNewCommands/src/main/native/include/frc2/command/ProfiledPIDCommand.h

@@ -12,7 +12,7 @@
 #include <frc/controller/ProfiledPIDController.h>
 #include <units/time.h>
 
-#include "frc2/command/CommandBase.h"
+#include "frc2/command/Command.h"
 #include "frc2/command/CommandHelper.h"
 
 namespace frc2 {
@@ -28,7 +28,7 @@ namespace frc2 {
  */
 template <class Distance>
 class ProfiledPIDCommand
-    : public CommandHelper<CommandBase, ProfiledPIDCommand<Distance>> {
+    : public CommandHelper<Command, ProfiledPIDCommand<Distance>> {
   using Distance_t = units::unit_t<Distance>;
   using Velocity =
       units::compound_unit<Distance, units::inverse<units::seconds>>;

wpilibNewCommands/src/main/native/include/frc2/command/ProfiledPIDSubsystem.h

@@ -7,7 +7,7 @@
 #include <frc/controller/ProfiledPIDController.h>
 #include <units/time.h>
 
-#include "frc2/command/SubsystemBase.h"
+#include "frc2/command/Subsystem.h"
 
 namespace frc2 {
 /**
@@ -19,7 +19,7 @@ namespace frc2 {
  * @see ProfiledPIDController
  */
 template <class Distance>
-class ProfiledPIDSubsystem : public SubsystemBase {
+class ProfiledPIDSubsystem : public Subsystem {
   using Distance_t = units::unit_t<Distance>;
   using Velocity =
       units::compound_unit<Distance, units::inverse<units::seconds>>;

wpilibNewCommands/src/main/native/include/frc2/command/ProxyCommand.h

@@ -9,7 +9,7 @@
 
 #include <wpi/FunctionExtras.h>
 
-#include "frc2/command/CommandBase.h"
+#include "frc2/command/Command.h"
 #include "frc2/command/CommandHelper.h"
 #include "frc2/command/SetUtilities.h"
 
@@ -21,7 +21,7 @@ namespace frc2 {
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-class ProxyCommand : public CommandHelper<CommandBase, ProxyCommand> {
+class ProxyCommand : public CommandHelper<Command, ProxyCommand> {
  public:
   /**
    * Creates a new ProxyCommand that schedules the supplied command when

wpilibNewCommands/src/main/native/include/frc2/command/RamseteCommand.h

@@ -19,7 +19,7 @@
 #include <units/length.h>
 #include <units/voltage.h>
 
-#include "frc2/command/CommandBase.h"
+#include "frc2/command/Command.h"
 #include "frc2/command/CommandHelper.h"
 
 namespace frc2 {
@@ -42,7 +42,7 @@ namespace frc2 {
  * @see RamseteController
  * @see Trajectory
  */
-class RamseteCommand : public CommandHelper<CommandBase, RamseteCommand> {
+class RamseteCommand : public CommandHelper<Command, RamseteCommand> {
  public:
   /**
    * Constructs a new RamseteCommand that, when executed, will follow the

wpilibNewCommands/src/main/native/include/frc2/command/RepeatCommand.h

@@ -13,7 +13,7 @@
 #include <memory>
 #include <utility>
 
-#include "frc2/command/CommandBase.h"
+#include "frc2/command/Command.h"
 #include "frc2/command/CommandHelper.h"
 
 namespace frc2 {
@@ -29,7 +29,7 @@ namespace frc2 {
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-class RepeatCommand : public CommandHelper<CommandBase, RepeatCommand> {
+class RepeatCommand : public CommandHelper<Command, RepeatCommand> {
  public:
   /**
    * Creates a new RepeatCommand. Will run another command repeatedly,

wpilibNewCommands/src/main/native/include/frc2/command/ScheduleCommand.h

@@ -8,7 +8,7 @@
 
 #include <wpi/SmallVector.h>
 
-#include "frc2/command/CommandBase.h"
+#include "frc2/command/Command.h"
 #include "frc2/command/CommandHelper.h"
 #include "frc2/command/SetUtilities.h"
 
@@ -21,7 +21,7 @@ namespace frc2 {
  *
  * This class is provided by the NewCommands VendorDep
  */
-class ScheduleCommand : public CommandHelper<CommandBase, ScheduleCommand> {
+class ScheduleCommand : public CommandHelper<Command, ScheduleCommand> {
  public:
   /**
    * Creates a new ScheduleCommand that schedules the given commands when

wpilibNewCommands/src/main/native/include/frc2/command/SelectCommand.h

@@ -18,7 +18,7 @@
 
 #include <wpi/sendable/SendableBuilder.h>
 
-#include "frc2/command/CommandBase.h"
+#include "frc2/command/Command.h"
 #include "frc2/command/PrintCommand.h"
 
 namespace frc2 {
@@ -35,7 +35,7 @@ namespace frc2 {
  * This class is provided by the NewCommands VendorDep
  */
 template <typename Key>
-class SelectCommand : public CommandHelper<CommandBase, SelectCommand<Key>> {
+class SelectCommand : public CommandHelper<Command, SelectCommand<Key>> {
  public:
   /**
    * Creates a new SelectCommand.
@@ -113,7 +113,7 @@ class SelectCommand : public CommandHelper<CommandBase, SelectCommand<Key>> {
   }
 
   void InitSendable(wpi::SendableBuilder& builder) override {
-    CommandBase::InitSendable(builder);
+    Command::InitSendable(builder);
 
     builder.AddStringProperty(
         "selected",

wpilibNewCommands/src/main/native/include/frc2/command/SequentialCommandGroup.h

@@ -37,7 +37,7 @@ const size_t invalid_index = std::numeric_limits<size_t>::max();
  * This class is provided by the NewCommands VendorDep
  */
 class SequentialCommandGroup
-    : public CommandHelper<CommandBase, SequentialCommandGroup> {
+    : public CommandHelper<Command, SequentialCommandGroup> {
  public:
   /**
    * Creates a new SequentialCommandGroup. The given commands will be run

wpilibNewCommands/src/main/native/include/frc2/command/Subsystem.h

@@ -5,8 +5,11 @@
 #pragma once
 
 #include <concepts>
+#include <string>
 #include <utility>
 
+#include <wpi/sendable/Sendable.h>
+
 #include "frc2/command/CommandScheduler.h"
 
 namespace frc2 {
@@ -23,22 +26,19 @@ class CommandPtr;
  * subsystem should generally remain encapsulated and not be shared by other
  * parts of the robot.
  *
- * <p>Subsystems must be registered with the scheduler with the
+ * <p>Subsystems are automatically registered with the scheduler with the
  * CommandScheduler.RegisterSubsystem() method in order for the
- * Periodic() method to be called.  It is recommended that this method be called
- * from the constructor of users' Subsystem implementations.  The
- * SubsystemBase class offers a simple base for user implementations
- * that handles this.
+ * Periodic() method to be called.
  *
  * This class is provided by the NewCommands VendorDep
  *
  * @see Command
  * @see CommandScheduler
- * @see SubsystemBase
  */
-class Subsystem {
+class Subsystem : public wpi::Sendable, public wpi::SendableHelper<Subsystem> {
  public:
-  virtual ~Subsystem();
+  ~Subsystem() override;
+
   /**
    * This method is called periodically by the CommandScheduler.  Useful for
    * updating subsystem-specific state that you don't want to offload to a
@@ -110,6 +110,43 @@ class Subsystem {
    */
   void Register();
 
+  /**
+   * Gets the name of this Subsystem.
+   *
+   * @return Name
+   */
+  std::string GetName() const;
+
+  /**
+   * Sets the name of this Subsystem.
+   *
+   * @param name name
+   */
+  void SetName(std::string_view name);
+
+  /**
+   * Gets the subsystem name of this Subsystem.
+   *
+   * @return Subsystem name
+   */
+  std::string GetSubsystem() const;
+
+  /**
+   * Sets the subsystem name of this Subsystem.
+   *
+   * @param name subsystem name
+   */
+  void SetSubsystem(std::string_view name);
+
+  /**
+   * Associate a Sendable with this Subsystem.
+   * Also update the child's name.
+   *
+   * @param name name to give child
+   * @param child sendable
+   */
+  void AddChild(std::string name, wpi::Sendable* child);
+
   /**
    * Constructs a command that runs an action once and finishes. Requires this
    * subsystem.
@@ -147,5 +184,10 @@ class Subsystem {
    */
   [[nodiscard]]
   CommandPtr RunEnd(std::function<void()> run, std::function<void()> end);
+
+  void InitSendable(wpi::SendableBuilder& builder) override;
+
+ protected:
+  Subsystem();
 };
 }  // namespace frc2

wpilibNewCommands/src/main/native/include/frc2/command/SubsystemBase.h

@@ -4,11 +4,7 @@
 
 #pragma once
 
-#include <string>
-#include <string_view>
-
-#include <wpi/sendable/Sendable.h>
-#include <wpi/sendable/SendableHelper.h>
+#include <wpi/deprecated.h>
 
 #include "frc2/command/Subsystem.h"
 
@@ -18,51 +14,13 @@ namespace frc2 {
  * provides a more intuitive method for setting the default command.
  *
  * This class is provided by the NewCommands VendorDep
+ *
+ * @deprecated All functionality provided by SubsystemBase has been merged into
+ * Subsystem. Use Subsystem instead.
  */
-class SubsystemBase : public Subsystem,
-                      public wpi::Sendable,
-                      public wpi::SendableHelper<SubsystemBase> {
- public:
-  void InitSendable(wpi::SendableBuilder& builder) override;
-
-  /**
-   * Gets the name of this Subsystem.
-   *
-   * @return Name
-   */
-  std::string GetName() const;
-
-  /**
-   * Sets the name of this Subsystem.
-   *
-   * @param name name
-   */
-  void SetName(std::string_view name);
-
-  /**
-   * Gets the subsystem name of this Subsystem.
-   *
-   * @return Subsystem name
-   */
-  std::string GetSubsystem() const;
-
-  /**
-   * Sets the subsystem name of this Subsystem.
-   *
-   * @param name subsystem name
-   */
-  void SetSubsystem(std::string_view name);
-
-  /**
-   * Associate a Sendable with this Subsystem.
-   * Also update the child's name.
-   *
-   * @param name name to give child
-   * @param child sendable
-   */
-  void AddChild(std::string name, wpi::Sendable* child);
-
+class [[deprecated("Use Subsystem instead")]] SubsystemBase : public Subsystem {
  protected:
+  WPI_DEPRECATED("Use Subsystem instead")
   SubsystemBase();
 };
 }  // namespace frc2

wpilibNewCommands/src/main/native/include/frc2/command/SwerveControllerCommand.h

@@ -21,7 +21,7 @@
 #include <units/time.h>
 #include <units/voltage.h>
 
-#include "CommandBase.h"
+#include "Command.h"
 #include "CommandHelper.h"
 
 #pragma once
@@ -51,7 +51,7 @@ namespace frc2 {
  */
 template <size_t NumModules>
 class SwerveControllerCommand
-    : public CommandHelper<CommandBase, SwerveControllerCommand<NumModules>> {
+    : public CommandHelper<Command, SwerveControllerCommand<NumModules>> {
   using voltsecondspermeter =
       units::compound_unit<units::voltage::volt, units::second,
                            units::inverse<units::meter>>;

wpilibNewCommands/src/main/native/include/frc2/command/TrapezoidProfileCommand.h

@@ -11,7 +11,7 @@
 #include <frc/Timer.h>
 #include <frc/trajectory/TrapezoidProfile.h>
 
-#include "frc2/command/CommandBase.h"
+#include "frc2/command/Command.h"
 #include "frc2/command/CommandHelper.h"
 
 namespace frc2 {
@@ -25,7 +25,7 @@ namespace frc2 {
  */
 template <class Distance>
 class TrapezoidProfileCommand
-    : public CommandHelper<CommandBase, TrapezoidProfileCommand<Distance>> {
+    : public CommandHelper<Command, TrapezoidProfileCommand<Distance>> {
   using Distance_t = units::unit_t<Distance>;
   using Velocity =
       units::compound_unit<Distance, units::inverse<units::seconds>>;

wpilibNewCommands/src/main/native/include/frc2/command/TrapezoidProfileSubsystem.h

@@ -7,7 +7,7 @@
 #include <frc/trajectory/TrapezoidProfile.h>
 #include <units/time.h>
 
-#include "frc2/command/SubsystemBase.h"
+#include "frc2/command/Subsystem.h"
 
 namespace frc2 {
 /**
@@ -18,7 +18,7 @@ namespace frc2 {
  * This class is provided by the NewCommands VendorDep
  */
 template <class Distance>
-class TrapezoidProfileSubsystem : public SubsystemBase {
+class TrapezoidProfileSubsystem : public Subsystem {
   using Distance_t = units::unit_t<Distance>;
   using Velocity =
       units::compound_unit<Distance, units::inverse<units::seconds>>;

wpilibNewCommands/src/main/native/include/frc2/command/WaitCommand.h

@@ -7,7 +7,7 @@
 #include <frc/Timer.h>
 #include <units/time.h>
 
-#include "frc2/command/CommandBase.h"
+#include "frc2/command/Command.h"
 #include "frc2/command/CommandHelper.h"
 
 namespace frc2 {
@@ -16,7 +16,7 @@ namespace frc2 {
  *
  * This class is provided by the NewCommands VendorDep
  */
-class WaitCommand : public CommandHelper<CommandBase, WaitCommand> {
+class WaitCommand : public CommandHelper<Command, WaitCommand> {
  public:
   /**
    * Creates a new WaitCommand.  This command will do nothing, and end after the

wpilibNewCommands/src/main/native/include/frc2/command/WaitUntilCommand.h

@@ -8,7 +8,7 @@
 
 #include <units/time.h>
 
-#include "frc2/command/CommandBase.h"
+#include "frc2/command/Command.h"
 #include "frc2/command/CommandHelper.h"
 
 namespace frc2 {
@@ -18,7 +18,7 @@ namespace frc2 {
  *
  * This class is provided by the NewCommands VendorDep
  */
-class WaitUntilCommand : public CommandHelper<CommandBase, WaitUntilCommand> {
+class WaitUntilCommand : public CommandHelper<Command, WaitUntilCommand> {
  public:
   /**
    * Creates a new WaitUntilCommand that ends after a given condition becomes

wpilibNewCommands/src/main/native/include/frc2/command/WrapperCommand.h

@@ -13,7 +13,7 @@
 #include <memory>
 #include <utility>
 
-#include "frc2/command/CommandBase.h"
+#include "frc2/command/Command.h"
 #include "frc2/command/CommandHelper.h"
 
 namespace frc2 {
@@ -24,7 +24,7 @@ namespace frc2 {
  * <p>Wrapped commands may only be used through the wrapper, trying to directly
  * schedule them or add them to a group will throw an exception.
  */
-class WrapperCommand : public CommandHelper<CommandBase, WrapperCommand> {
+class WrapperCommand : public CommandHelper<Command, WrapperCommand> {
  public:
   /**
    * Wrap a command.