[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/java/edu/wpi/first/wpilibj2/command/Command.java

@@ -7,6 +7,10 @@ package edu.wpi.first.wpilibj2.command;
 import static edu.wpi.first.util.ErrorMessages.requireNonNullParam;
 
 import edu.wpi.first.util.function.BooleanConsumer;
+import edu.wpi.first.util.sendable.Sendable;
+import edu.wpi.first.util.sendable.SendableBuilder;
+import edu.wpi.first.util.sendable.SendableRegistry;
+import java.util.HashSet;
 import java.util.Set;
 import java.util.function.BooleanSupplier;
 
@@ -20,12 +24,19 @@ import java.util.function.BooleanSupplier;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public interface Command {
+public abstract class Command implements Sendable {
+  protected Set<Subsystem> m_requirements = new HashSet<>();
+
+  protected Command() {
+    String name = getClass().getName();
+    SendableRegistry.add(this, name.substring(name.lastIndexOf('.') + 1));
+  }
+
   /** The initial subroutine of a command. Called once when the command is initially scheduled. */
-  default void initialize() {}
+  public void initialize() {}
 
   /** The main body of a command. Called repeatedly while the command is scheduled. */
-  default void execute() {}
+  public void execute() {}
 
   /**
    * The action to take when the command ends. Called when either the command finishes normally, or
@@ -36,7 +47,7 @@ public interface Command {
    *
    * @param interrupted whether the command was interrupted/canceled
    */
-  default void end(boolean interrupted) {}
+  public void end(boolean interrupted) {}
 
   /**
    * Whether the command has finished. Once a command finishes, the scheduler will call its end()
@@ -44,7 +55,7 @@ public interface Command {
    *
    * @return whether the command has finished.
    */
-  default boolean isFinished() {
+  public boolean isFinished() {
     return false;
   }
 
@@ -60,7 +71,63 @@ public interface Command {
    * @return the set of subsystems that are required
    * @see InterruptionBehavior
    */
-  Set<Subsystem> getRequirements();
+  public Set<Subsystem> getRequirements() {
+    return m_requirements;
+  }
+
+  /**
+   * Adds the specified subsystems to the requirements of the command. The scheduler will prevent
+   * two commands that require the same subsystem from being scheduled simultaneously.
+   *
+   * <p>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 requirements to add
+   */
+  public final void addRequirements(Subsystem... requirements) {
+    for (Subsystem requirement : requirements) {
+      m_requirements.add(requireNonNullParam(requirement, "requirement", "addRequirements"));
+    }
+  }
+
+  /**
+   * Gets the name of this Command.
+   *
+   * <p>By default, the simple class name is used. This can be changed with {@link
+   * #setName(String)}.
+   *
+   * @return The display name of the Command
+   */
+  public String getName() {
+    return SendableRegistry.getName(this);
+  }
+
+  /**
+   * Sets the name of this Command.
+   *
+   * @param name The display name of the Command.
+   */
+  public void setName(String name) {
+    SendableRegistry.setName(this, name);
+  }
+
+  /**
+   * Gets the subsystem name of this Command.
+   *
+   * @return Subsystem name
+   */
+  public String getSubsystem() {
+    return SendableRegistry.getSubsystem(this);
+  }
+
+  /**
+   * Sets the subsystem name of this Command.
+   *
+   * @param subsystem subsystem name
+   */
+  public void setSubsystem(String subsystem) {
+    SendableRegistry.setSubsystem(this, subsystem);
+  }
 
   /**
    * Decorates this command with a timeout. If the specified timeout is exceeded before the command
@@ -75,7 +142,7 @@ public interface Command {
    * @param seconds the timeout duration
    * @return the command with the timeout added
    */
-  default ParallelRaceGroup withTimeout(double seconds) {
+  public ParallelRaceGroup withTimeout(double seconds) {
     return raceWith(new WaitCommand(seconds));
   }
 
@@ -93,7 +160,7 @@ public interface Command {
    * @return the command with the interrupt condition added
    * @see #onlyWhile(BooleanSupplier)
    */
-  default ParallelRaceGroup until(BooleanSupplier condition) {
+  public ParallelRaceGroup until(BooleanSupplier condition) {
     return raceWith(new WaitUntilCommand(condition));
   }
 
@@ -111,7 +178,7 @@ public interface Command {
    * @return the command with the run condition added
    * @see #until(BooleanSupplier)
    */
-  default ParallelRaceGroup onlyWhile(BooleanSupplier condition) {
+  public ParallelRaceGroup onlyWhile(BooleanSupplier condition) {
     return until(() -> !condition.getAsBoolean());
   }
 
@@ -128,7 +195,7 @@ public interface Command {
    * @param requirements the required subsystems
    * @return the decorated command
    */
-  default SequentialCommandGroup beforeStarting(Runnable toRun, Subsystem... requirements) {
+  public SequentialCommandGroup beforeStarting(Runnable toRun, Subsystem... requirements) {
     return beforeStarting(new InstantCommand(toRun, requirements));
   }
 
@@ -144,7 +211,7 @@ public interface Command {
    * @param before the command to run before this one
    * @return the decorated command
    */
-  default SequentialCommandGroup beforeStarting(Command before) {
+  public SequentialCommandGroup beforeStarting(Command before) {
     return new SequentialCommandGroup(before, this);
   }
 
@@ -161,7 +228,7 @@ public interface Command {
    * @param requirements the required subsystems
    * @return the decorated command
    */
-  default SequentialCommandGroup andThen(Runnable toRun, Subsystem... requirements) {
+  public SequentialCommandGroup andThen(Runnable toRun, Subsystem... requirements) {
     return andThen(new InstantCommand(toRun, requirements));
   }
 
@@ -178,7 +245,7 @@ public interface Command {
    * @param next the commands to run next
    * @return the decorated command
    */
-  default SequentialCommandGroup andThen(Command... next) {
+  public SequentialCommandGroup andThen(Command... next) {
     SequentialCommandGroup group = new SequentialCommandGroup(this);
     group.addCommands(next);
     return group;
@@ -198,7 +265,7 @@ public interface Command {
    * @param parallel the commands to run in parallel
    * @return the decorated command
    */
-  default ParallelDeadlineGroup deadlineWith(Command... parallel) {
+  public ParallelDeadlineGroup deadlineWith(Command... parallel) {
     return new ParallelDeadlineGroup(this, parallel);
   }
 
@@ -216,7 +283,7 @@ public interface Command {
    * @param parallel the commands to run in parallel
    * @return the decorated command
    */
-  default ParallelCommandGroup alongWith(Command... parallel) {
+  public ParallelCommandGroup alongWith(Command... parallel) {
     ParallelCommandGroup group = new ParallelCommandGroup(this);
     group.addCommands(parallel);
     return group;
@@ -236,7 +303,7 @@ public interface Command {
    * @param parallel the commands to run in parallel
    * @return the decorated command
    */
-  default ParallelRaceGroup raceWith(Command... parallel) {
+  public ParallelRaceGroup raceWith(Command... parallel) {
     ParallelRaceGroup group = new ParallelRaceGroup(this);
     group.addCommands(parallel);
     return group;
@@ -254,7 +321,7 @@ public interface Command {
    *
    * @return the decorated command
    */
-  default RepeatCommand repeatedly() {
+  public RepeatCommand repeatedly() {
     return new RepeatCommand(this);
   }
 
@@ -265,7 +332,7 @@ public interface Command {
    *
    * @return the decorated command
    */
-  default ProxyCommand asProxy() {
+  public ProxyCommand asProxy() {
     return new ProxyCommand(this);
   }
 
@@ -284,7 +351,7 @@ public interface Command {
    * @return the decorated command
    * @see #onlyIf(BooleanSupplier)
    */
-  default ConditionalCommand unless(BooleanSupplier condition) {
+  public ConditionalCommand unless(BooleanSupplier condition) {
     return new ConditionalCommand(new InstantCommand(), this, condition);
   }
 
@@ -303,7 +370,7 @@ public interface Command {
    * @return the decorated command
    * @see #unless(BooleanSupplier)
    */
-  default ConditionalCommand onlyIf(BooleanSupplier condition) {
+  public ConditionalCommand onlyIf(BooleanSupplier condition) {
     return unless(() -> !condition.getAsBoolean());
   }
 
@@ -313,7 +380,7 @@ public interface Command {
    * @param doesRunWhenDisabled true to run when disabled.
    * @return the decorated command
    */
-  default WrapperCommand ignoringDisable(boolean doesRunWhenDisabled) {
+  public WrapperCommand ignoringDisable(boolean doesRunWhenDisabled) {
     return new WrapperCommand(this) {
       @Override
       public boolean runsWhenDisabled() {
@@ -328,7 +395,7 @@ public interface Command {
    * @param interruptBehavior the desired interrupt behavior
    * @return the decorated command
    */
-  default WrapperCommand withInterruptBehavior(InterruptionBehavior interruptBehavior) {
+  public WrapperCommand withInterruptBehavior(InterruptionBehavior interruptBehavior) {
     return new WrapperCommand(this) {
       @Override
       public InterruptionBehavior getInterruptionBehavior() {
@@ -345,7 +412,7 @@ public interface Command {
    *     interrupted.
    * @return the decorated command
    */
-  default WrapperCommand finallyDo(BooleanConsumer end) {
+  public WrapperCommand finallyDo(BooleanConsumer end) {
     requireNonNullParam(end, "end", "Command.finallyDo()");
     return new WrapperCommand(this) {
       @Override
@@ -363,7 +430,7 @@ public interface Command {
    * @param handler a lambda to run when the command is interrupted
    * @return the decorated command
    */
-  default WrapperCommand handleInterrupt(Runnable handler) {
+  public WrapperCommand handleInterrupt(Runnable handler) {
     requireNonNullParam(handler, "handler", "Command.handleInterrupt()");
     return finallyDo(
         interrupted -> {
@@ -374,7 +441,7 @@ public interface Command {
   }
 
   /** Schedules this command. */
-  default void schedule() {
+  public void schedule() {
     CommandScheduler.getInstance().schedule(this);
   }
 
@@ -384,7 +451,7 @@ public interface Command {
    *
    * @see CommandScheduler#cancel(Command...)
    */
-  default void cancel() {
+  public void cancel() {
     CommandScheduler.getInstance().cancel(this);
   }
 
@@ -394,7 +461,7 @@ public interface Command {
    *
    * @return Whether the command is scheduled.
    */
-  default boolean isScheduled() {
+  public boolean isScheduled() {
     return CommandScheduler.getInstance().isScheduled(this);
   }
 
@@ -404,7 +471,7 @@ public interface Command {
    * @param requirement the subsystem to inquire about
    * @return whether the subsystem is required
    */
-  default boolean hasRequirement(Subsystem requirement) {
+  public boolean hasRequirement(Subsystem requirement) {
     return getRequirements().contains(requirement);
   }
 
@@ -414,7 +481,7 @@ public interface Command {
    * @return a variant of {@link InterruptionBehavior}, defaulting to {@link
    *     InterruptionBehavior#kCancelSelf kCancelSelf}.
    */
-  default InterruptionBehavior getInterruptionBehavior() {
+  public InterruptionBehavior getInterruptionBehavior() {
     return InterruptionBehavior.kCancelSelf;
   }
 
@@ -424,43 +491,52 @@ public interface Command {
    *
    * @return whether the command should run when the robot is disabled
    */
-  default boolean runsWhenDisabled() {
+  public boolean runsWhenDisabled() {
     return false;
   }
 
-  /**
-   * Gets the name of this Command. Defaults to the simple class name if not overridden.
-   *
-   * @return The display name of the Command
-   */
-  default String getName() {
-    return this.getClass().getSimpleName();
-  }
-
-  /**
-   * Sets the name of this Command. Nullop if not overridden.
-   *
-   * @param name The display name of the Command.
-   */
-  default void setName(String name) {}
-
   /**
    * Decorates this Command with a name.
    *
    * @param name name
    * @return the decorated Command
    */
-  default WrapperCommand withName(String name) {
+  public WrapperCommand withName(String name) {
     WrapperCommand wrapper = new WrapperCommand(Command.this) {};
     wrapper.setName(name);
     return wrapper;
   }
 
+  @Override
+  public void initSendable(SendableBuilder builder) {
+    builder.setSmartDashboardType("Command");
+    builder.addStringProperty(".name", this::getName, null);
+    builder.addBooleanProperty(
+        "running",
+        this::isScheduled,
+        value -> {
+          if (value) {
+            if (!isScheduled()) {
+              schedule();
+            }
+          } else {
+            if (isScheduled()) {
+              cancel();
+            }
+          }
+        });
+    builder.addBooleanProperty(
+        ".isParented", () -> CommandScheduler.getInstance().isComposed(this), null);
+    builder.addStringProperty(
+        "interruptBehavior", () -> getInterruptionBehavior().toString(), null);
+    builder.addBooleanProperty("runsWhenDisabled", this::runsWhenDisabled, null);
+  }
+
   /**
    * An enum describing the command's behavior when another command with a shared requirement is
    * scheduled.
    */
-  enum InterruptionBehavior {
+  public enum InterruptionBehavior {
     /**
      * This command ends, {@link #end(boolean) end(true)} is called, and the incoming command is
      * scheduled normally.

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/CommandBase.java

@@ -4,107 +4,16 @@
 
 package edu.wpi.first.wpilibj2.command;
 
-import static edu.wpi.first.util.ErrorMessages.requireNonNullParam;
-
 import edu.wpi.first.util.sendable.Sendable;
-import edu.wpi.first.util.sendable.SendableBuilder;
-import edu.wpi.first.util.sendable.SendableRegistry;
-import java.util.HashSet;
-import java.util.Set;
 
 /**
  * A {@link Sendable} base class for {@link Command}s.
  *
  * <p>This class is provided by the NewCommands VendorDep
+ *
+ * @deprecated All functionality provided by {@link CommandBase} has been merged into {@link
+ *     Command}. Use {@link Command} instead.
  */
-public abstract class CommandBase implements Sendable, Command {
-  protected Set<Subsystem> m_requirements = new HashSet<>();
-
-  protected CommandBase() {
-    String name = getClass().getName();
-    SendableRegistry.add(this, name.substring(name.lastIndexOf('.') + 1));
-  }
-
-  /**
-   * Adds the specified subsystems to the requirements of the command. The scheduler will prevent
-   * two commands that require the same subsystem from being scheduled simultaneously.
-   *
-   * <p>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 requirements to add
-   */
-  public final void addRequirements(Subsystem... requirements) {
-    for (Subsystem requirement : requirements) {
-      m_requirements.add(requireNonNullParam(requirement, "requirement", "addRequirements"));
-    }
-  }
-
-  @Override
-  public Set<Subsystem> getRequirements() {
-    return m_requirements;
-  }
-
-  @Override
-  public String getName() {
-    return SendableRegistry.getName(this);
-  }
-
-  /**
-   * Sets the name of this Command.
-   *
-   * @param name name
-   */
-  @Override
-  public void setName(String name) {
-    SendableRegistry.setName(this, name);
-  }
-
-  /**
-   * Gets the subsystem name of this Command.
-   *
-   * @return Subsystem name
-   */
-  public String getSubsystem() {
-    return SendableRegistry.getSubsystem(this);
-  }
-
-  /**
-   * Sets the subsystem name of this Command.
-   *
-   * @param subsystem subsystem name
-   */
-  public void setSubsystem(String subsystem) {
-    SendableRegistry.setSubsystem(this, subsystem);
-  }
-
-  /**
-   * Initializes this sendable. Useful for allowing implementations to easily extend SendableBase.
-   *
-   * @param builder the builder used to construct this sendable
-   */
-  @Override
-  public void initSendable(SendableBuilder builder) {
-    builder.setSmartDashboardType("Command");
-    builder.addStringProperty(".name", this::getName, null);
-    builder.addBooleanProperty(
-        "running",
-        this::isScheduled,
-        value -> {
-          if (value) {
-            if (!isScheduled()) {
-              schedule();
-            }
-          } else {
-            if (isScheduled()) {
-              cancel();
-            }
-          }
-        });
-    builder.addBooleanProperty(
-        ".isParented", () -> CommandScheduler.getInstance().isComposed(this), null);
-    builder.addStringProperty(
-        "interruptBehavior", () -> getInterruptionBehavior().toString(), null);
-    builder.addBooleanProperty("runsWhenDisabled", this::runsWhenDisabled, null);
-  }
-}
+@Deprecated(since = "2024", forRemoval = true)
+@SuppressWarnings("PMD.AbstractClassWithoutAnyMethod")
+public abstract class CommandBase extends Command {}

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/CommandScheduler.java

@@ -362,6 +362,15 @@ public final class CommandScheduler implements NTSendable, AutoCloseable {
     m_subsystems.keySet().removeAll(Set.of(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.
+   */
+  public void unregisterAllSubsystems() {
+    m_subsystems.clear();
+  }
+
   /**
    * Sets the default command for a subsystem. Registers that subsystem if it is not already
    * registered. Default commands will run whenever there is no other command currently scheduled

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/Commands.java

@@ -21,7 +21,7 @@ public final class Commands {
    *
    * @return the command
    */
-  public static CommandBase none() {
+  public static Command none() {
     return new InstantCommand();
   }
 
@@ -35,7 +35,7 @@ public final class Commands {
    * @return the command
    * @see InstantCommand
    */
-  public static CommandBase runOnce(Runnable action, Subsystem... requirements) {
+  public static Command runOnce(Runnable action, Subsystem... requirements) {
     return new InstantCommand(action, requirements);
   }
 
@@ -47,7 +47,7 @@ public final class Commands {
    * @return the command
    * @see RunCommand
    */
-  public static CommandBase run(Runnable action, Subsystem... requirements) {
+  public static Command run(Runnable action, Subsystem... requirements) {
     return new RunCommand(action, requirements);
   }
 
@@ -61,7 +61,7 @@ public final class Commands {
    * @return the command
    * @see StartEndCommand
    */
-  public static CommandBase startEnd(Runnable start, Runnable end, Subsystem... requirements) {
+  public static Command startEnd(Runnable start, Runnable end, Subsystem... requirements) {
     return new StartEndCommand(start, end, requirements);
   }
 
@@ -74,7 +74,7 @@ public final class Commands {
    * @param requirements subsystems the action requires
    * @return the command
    */
-  public static CommandBase runEnd(Runnable run, Runnable end, Subsystem... requirements) {
+  public static Command runEnd(Runnable run, Runnable end, Subsystem... requirements) {
     requireNonNullParam(end, "end", "Command.runEnd");
     return new FunctionalCommand(
         () -> {}, run, interrupted -> end.run(), () -> false, requirements);
@@ -87,7 +87,7 @@ public final class Commands {
    * @return the command
    * @see PrintCommand
    */
-  public static CommandBase print(String message) {
+  public static Command print(String message) {
     return new PrintCommand(message);
   }
 
@@ -100,7 +100,7 @@ public final class Commands {
    * @return the command
    * @see WaitCommand
    */
-  public static CommandBase waitSeconds(double seconds) {
+  public static Command waitSeconds(double seconds) {
     return new WaitCommand(seconds);
   }
 
@@ -111,7 +111,7 @@ public final class Commands {
    * @return the command
    * @see WaitUntilCommand
    */
-  public static CommandBase waitUntil(BooleanSupplier condition) {
+  public static Command waitUntil(BooleanSupplier condition) {
     return new WaitUntilCommand(condition);
   }
 
@@ -126,7 +126,7 @@ public final class Commands {
    * @return the command
    * @see ConditionalCommand
    */
-  public static CommandBase either(Command onTrue, Command onFalse, BooleanSupplier selector) {
+  public static Command either(Command onTrue, Command onFalse, BooleanSupplier selector) {
     return new ConditionalCommand(onTrue, onFalse, selector);
   }
 
@@ -138,7 +138,7 @@ public final class Commands {
    * @return the command
    * @see SelectCommand
    */
-  public static CommandBase select(Map<Object, Command> commands, Supplier<Object> selector) {
+  public static Command select(Map<Object, Command> commands, Supplier<Object> selector) {
     return new SelectCommand(commands, selector);
   }
 
@@ -149,7 +149,7 @@ public final class Commands {
    * @return the command group
    * @see SequentialCommandGroup
    */
-  public static CommandBase sequence(Command... commands) {
+  public static Command sequence(Command... commands) {
     return new SequentialCommandGroup(commands);
   }
 
@@ -164,7 +164,7 @@ public final class Commands {
    * @see SequentialCommandGroup
    * @see Command#repeatedly()
    */
-  public static CommandBase repeatingSequence(Command... commands) {
+  public static Command repeatingSequence(Command... commands) {
     return sequence(commands).repeatedly();
   }
 
@@ -175,7 +175,7 @@ public final class Commands {
    * @return the command
    * @see ParallelCommandGroup
    */
-  public static CommandBase parallel(Command... commands) {
+  public static Command parallel(Command... commands) {
     return new ParallelCommandGroup(commands);
   }
 
@@ -187,7 +187,7 @@ public final class Commands {
    * @return the command group
    * @see ParallelRaceGroup
    */
-  public static CommandBase race(Command... commands) {
+  public static Command race(Command... commands) {
     return new ParallelRaceGroup(commands);
   }
 
@@ -200,7 +200,7 @@ public final class Commands {
    * @return the command group
    * @see ParallelDeadlineGroup
    */
-  public static CommandBase deadline(Command deadline, Command... commands) {
+  public static Command deadline(Command deadline, Command... commands) {
     return new ParallelDeadlineGroup(deadline, commands);
   }
 

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/ConditionalCommand.java

@@ -19,7 +19,7 @@ import java.util.function.BooleanSupplier;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public class ConditionalCommand extends CommandBase {
+public class ConditionalCommand extends Command {
   private final Command m_onTrue;
   private final Command m_onFalse;
   private final BooleanSupplier m_condition;

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/FunctionalCommand.java

@@ -17,7 +17,7 @@ import java.util.function.Consumer;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public class FunctionalCommand extends CommandBase {
+public class FunctionalCommand extends Command {
   protected final Runnable m_onInit;
   protected final Runnable m_onExecute;
   protected final Consumer<Boolean> m_onEnd;

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/MecanumControllerCommand.java

@@ -38,7 +38,7 @@ import java.util.function.Supplier;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public class MecanumControllerCommand extends CommandBase {
+public class MecanumControllerCommand extends Command {
   private final Timer m_timer = new Timer();
   private final boolean m_usePID;
   private final Trajectory m_trajectory;

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/NotifierCommand.java

@@ -17,7 +17,7 @@ import edu.wpi.first.wpilibj.Notifier;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public class NotifierCommand extends CommandBase {
+public class NotifierCommand extends Command {
   protected final Notifier m_notifier;
   protected final double m_period;
 

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/PIDCommand.java

@@ -18,7 +18,7 @@ import java.util.function.DoubleSupplier;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public class PIDCommand extends CommandBase {
+public class PIDCommand extends Command {
   protected final PIDController m_controller;
   protected DoubleSupplier m_measurement;
   protected DoubleSupplier m_setpoint;

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/PIDSubsystem.java

@@ -14,7 +14,7 @@ import edu.wpi.first.math.controller.PIDController;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public abstract class PIDSubsystem extends SubsystemBase {
+public abstract class PIDSubsystem extends Subsystem {
   protected final PIDController m_controller;
   protected boolean m_enabled;
 

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/ParallelCommandGroup.java

@@ -17,7 +17,7 @@ import java.util.Map;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public class ParallelCommandGroup extends CommandBase {
+public class ParallelCommandGroup extends Command {
   // maps commands in this composition to whether they are still running
   private final Map<Command, Boolean> m_commands = new HashMap<>();
   private boolean m_runWhenDisabled = true;

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/ParallelDeadlineGroup.java

@@ -20,7 +20,7 @@ import java.util.Map;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public class ParallelDeadlineGroup extends CommandBase {
+public class ParallelDeadlineGroup extends Command {
   // maps commands in this composition to whether they are still running
   private final Map<Command, Boolean> m_commands = new HashMap<>();
   private boolean m_runWhenDisabled = true;

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/ParallelRaceGroup.java

@@ -18,7 +18,7 @@ import java.util.Set;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public class ParallelRaceGroup extends CommandBase {
+public class ParallelRaceGroup extends Command {
   private final Set<Command> m_commands = new HashSet<>();
   private boolean m_runWhenDisabled = true;
   private boolean m_finished = true;

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/ProfiledPIDCommand.java

@@ -20,7 +20,7 @@ import java.util.function.Supplier;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public class ProfiledPIDCommand extends CommandBase {
+public class ProfiledPIDCommand extends Command {
   protected final ProfiledPIDController m_controller;
   protected DoubleSupplier m_measurement;
   protected Supplier<State> m_goal;

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/ProfiledPIDSubsystem.java

@@ -16,7 +16,7 @@ import edu.wpi.first.math.trajectory.TrapezoidProfile;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public abstract class ProfiledPIDSubsystem extends SubsystemBase {
+public abstract class ProfiledPIDSubsystem extends Subsystem {
   protected final ProfiledPIDController m_controller;
   protected boolean m_enabled;
 

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/ProxyCommand.java

@@ -15,7 +15,7 @@ import java.util.function.Supplier;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public class ProxyCommand extends CommandBase {
+public class ProxyCommand extends Command {
   private final Supplier<Command> m_supplier;
   private Command m_command;
 

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/RamseteCommand.java

@@ -33,7 +33,7 @@ import java.util.function.Supplier;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public class RamseteCommand extends CommandBase {
+public class RamseteCommand extends Command {
   private final Timer m_timer = new Timer();
   private final boolean m_usePID;
   private final Trajectory m_trajectory;

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/RepeatCommand.java

@@ -19,7 +19,7 @@ import edu.wpi.first.util.sendable.SendableBuilder;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public class RepeatCommand extends CommandBase {
+public class RepeatCommand extends Command {
   protected final Command m_command;
   private boolean m_ended;
 

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/ScheduleCommand.java

@@ -13,7 +13,7 @@ import java.util.Set;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public class ScheduleCommand extends CommandBase {
+public class ScheduleCommand extends Command {
   private final Set<Command> m_toSchedule;
 
   /**

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/SelectCommand.java

@@ -20,7 +20,7 @@ import java.util.function.Supplier;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public class SelectCommand extends CommandBase {
+public class SelectCommand extends Command {
   private final Map<Object, Command> m_commands;
   private final Supplier<Object> m_selector;
   private Command m_selectedCommand;

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/SequentialCommandGroup.java

@@ -17,7 +17,7 @@ import java.util.List;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public class SequentialCommandGroup extends CommandBase {
+public class SequentialCommandGroup extends Command {
   private final List<Command> m_commands = new ArrayList<>();
   private int m_currentCommandIndex = -1;
   private boolean m_runWhenDisabled = true;

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/Subsystem.java

@@ -4,6 +4,10 @@
 
 package edu.wpi.first.wpilibj2.command;
 
+import edu.wpi.first.util.sendable.Sendable;
+import edu.wpi.first.util.sendable.SendableBuilder;
+import edu.wpi.first.util.sendable.SendableRegistry;
+
 /**
  * A robot subsystem. Subsystems are the basic unit of robot organization in the Command-based
  * framework; they encapsulate low-level hardware objects (motor controllers, sensors, etc.) and
@@ -13,29 +17,34 @@ package edu.wpi.first.wpilibj2.command;
  * their {@link Command#getRequirements()} method, and resources used within a 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 {@link
- * CommandScheduler#registerSubsystem(Subsystem...)} method in order for the {@link
- * Subsystem#periodic()} method to be called. It is recommended that this method be called from the
- * constructor of users' Subsystem implementations. The {@link SubsystemBase} class offers a simple
- * base for user implementations that handles this.
+ * <p>Subsystems are automatically registered with the default scheduler in order for the {@link
+ * Subsystem#periodic()} method to be called.
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public interface Subsystem {
+public abstract class Subsystem implements Sendable {
+  /** Constructor. */
+  public Subsystem() {
+    String name = this.getClass().getSimpleName();
+    name = name.substring(name.lastIndexOf('.') + 1);
+    SendableRegistry.addLW(this, name, name);
+    CommandScheduler.getInstance().registerSubsystem(this);
+  }
+
   /**
    * This method is called periodically by the {@link CommandScheduler}. Useful for updating
    * subsystem-specific state that you don't want to offload to a {@link Command}. Teams should try
    * to be consistent within their own codebases about which responsibilities will be handled by
    * Commands, and which will be handled here.
    */
-  default void periodic() {}
+  public void periodic() {}
 
   /**
    * This method is called periodically by the {@link CommandScheduler}. Useful for updating
    * subsystem-specific state that needs to be maintained for simulations, such as for updating
    * {@link edu.wpi.first.wpilibj.simulation} classes and setting simulated sensor readings.
    */
-  default void simulationPeriodic() {}
+  public void simulationPeriodic() {}
 
   /**
    * Sets the default {@link Command} of the subsystem. The default command will be automatically
@@ -46,7 +55,7 @@ public interface Subsystem {
    *
    * @param defaultCommand the default command to associate with this subsystem
    */
-  default void setDefaultCommand(Command defaultCommand) {
+  public void setDefaultCommand(Command defaultCommand) {
     CommandScheduler.getInstance().setDefaultCommand(this, defaultCommand);
   }
 
@@ -54,7 +63,7 @@ public interface Subsystem {
    * Removes the default command for the subsystem. This will not cancel the default command if it
    * is currently running.
    */
-  default void removeDefaultCommand() {
+  public void removeDefaultCommand() {
     CommandScheduler.getInstance().removeDefaultCommand(this);
   }
 
@@ -64,7 +73,7 @@ public interface Subsystem {
    *
    * @return the default command associated with this subsystem
    */
-  default Command getDefaultCommand() {
+  public Command getDefaultCommand() {
     return CommandScheduler.getInstance().getDefaultCommand(this);
   }
 
@@ -74,15 +83,51 @@ public interface Subsystem {
    *
    * @return the scheduled command currently requiring this subsystem
    */
-  default Command getCurrentCommand() {
+  public Command getCurrentCommand() {
     return CommandScheduler.getInstance().requiring(this);
   }
 
+  /**
+   * Gets the name of this Subsystem.
+   *
+   * @return Name
+   */
+  public String getName() {
+    return SendableRegistry.getName(this);
+  }
+
+  /**
+   * Sets the name of this Subsystem.
+   *
+   * @param name name
+   */
+  public void setName(String name) {
+    SendableRegistry.setName(this, name);
+  }
+
+  /**
+   * Gets the subsystem name of this Subsystem.
+   *
+   * @return Subsystem name
+   */
+  public String getSubsystem() {
+    return SendableRegistry.getSubsystem(this);
+  }
+
+  /**
+   * Sets the subsystem name of this Subsystem.
+   *
+   * @param subsystem subsystem name
+   */
+  public void setSubsystem(String subsystem) {
+    SendableRegistry.setSubsystem(this, subsystem);
+  }
+
   /**
    * Registers this subsystem with the {@link CommandScheduler}, allowing its {@link
    * Subsystem#periodic()} method to be called when the scheduler runs.
    */
-  default void register() {
+  public void register() {
     CommandScheduler.getInstance().registerSubsystem(this);
   }
 
@@ -93,7 +138,7 @@ public interface Subsystem {
    * @return the command
    * @see InstantCommand
    */
-  default CommandBase runOnce(Runnable action) {
+  public Command runOnce(Runnable action) {
     return Commands.runOnce(action, this);
   }
 
@@ -105,7 +150,7 @@ public interface Subsystem {
    * @return the command
    * @see RunCommand
    */
-  default CommandBase run(Runnable action) {
+  public Command run(Runnable action) {
     return Commands.run(action, this);
   }
 
@@ -118,7 +163,7 @@ public interface Subsystem {
    * @return the command
    * @see StartEndCommand
    */
-  default CommandBase startEnd(Runnable start, Runnable end) {
+  public Command startEnd(Runnable start, Runnable end) {
     return Commands.startEnd(start, end, this);
   }
 
@@ -130,7 +175,33 @@ public interface Subsystem {
    * @param end the action to run on interrupt
    * @return the command
    */
-  default CommandBase runEnd(Runnable run, Runnable end) {
+  public Command runEnd(Runnable run, Runnable end) {
     return Commands.runEnd(run, end, this);
   }
+
+  /**
+   * Associates a {@link Sendable} with this Subsystem. Also update the child's name.
+   *
+   * @param name name to give child
+   * @param child sendable
+   */
+  public void addChild(String name, Sendable child) {
+    SendableRegistry.addLW(child, getSubsystem(), name);
+  }
+
+  @Override
+  public void initSendable(SendableBuilder builder) {
+    builder.setSmartDashboardType("Subsystem");
+
+    builder.addBooleanProperty(".hasDefault", () -> getDefaultCommand() != null, null);
+    builder.addStringProperty(
+        ".default",
+        () -> getDefaultCommand() != null ? getDefaultCommand().getName() : "none",
+        null);
+    builder.addBooleanProperty(".hasCommand", () -> getCurrentCommand() != null, null);
+    builder.addStringProperty(
+        ".command",
+        () -> getCurrentCommand() != null ? getCurrentCommand().getName() : "none",
+        null);
+  }
 }

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/SubsystemBase.java

@@ -4,84 +4,15 @@
 
 package edu.wpi.first.wpilibj2.command;
 
-import edu.wpi.first.util.sendable.Sendable;
-import edu.wpi.first.util.sendable.SendableBuilder;
-import edu.wpi.first.util.sendable.SendableRegistry;
-
 /**
  * A base for subsystems that handles registration in the constructor, and provides a more intuitive
  * method for setting the default command.
  *
  * <p>This class is provided by the NewCommands VendorDep
+ *
+ * @deprecated All functionality provided by {@link SubsystemBase} has been merged into {@link
+ *     Subsystem}. Use {@link Subsystem} instead.
  */
-public abstract class SubsystemBase implements Subsystem, Sendable {
-  /** Constructor. */
-  public SubsystemBase() {
-    String name = this.getClass().getSimpleName();
-    name = name.substring(name.lastIndexOf('.') + 1);
-    SendableRegistry.addLW(this, name, name);
-    CommandScheduler.getInstance().registerSubsystem(this);
-  }
-
-  /**
-   * Gets the name of this Subsystem.
-   *
-   * @return Name
-   */
-  public String getName() {
-    return SendableRegistry.getName(this);
-  }
-
-  /**
-   * Sets the name of this Subsystem.
-   *
-   * @param name name
-   */
-  public void setName(String name) {
-    SendableRegistry.setName(this, name);
-  }
-
-  /**
-   * Gets the subsystem name of this Subsystem.
-   *
-   * @return Subsystem name
-   */
-  public String getSubsystem() {
-    return SendableRegistry.getSubsystem(this);
-  }
-
-  /**
-   * Sets the subsystem name of this Subsystem.
-   *
-   * @param subsystem subsystem name
-   */
-  public void setSubsystem(String subsystem) {
-    SendableRegistry.setSubsystem(this, subsystem);
-  }
-
-  /**
-   * Associates a {@link Sendable} with this Subsystem. Also update the child's name.
-   *
-   * @param name name to give child
-   * @param child sendable
-   */
-  public void addChild(String name, Sendable child) {
-    SendableRegistry.addLW(child, getSubsystem(), name);
-  }
-
-  @Override
-  public void initSendable(SendableBuilder builder) {
-    builder.setSmartDashboardType("Subsystem");
-
-    builder.addBooleanProperty(".hasDefault", () -> getDefaultCommand() != null, null);
-    builder.addStringProperty(
-        ".default",
-        () -> getDefaultCommand() != null ? getDefaultCommand().getName() : "none",
-        null);
-    builder.addBooleanProperty(".hasCommand", () -> getCurrentCommand() != null, null);
-    builder.addStringProperty(
-        ".command",
-        () -> getCurrentCommand() != null ? getCurrentCommand().getName() : "none",
-        null);
-  }
-}
+@Deprecated(since = "2024", forRemoval = true)
+@SuppressWarnings("PMD.AbstractClassWithoutAnyMethod")
+public abstract class SubsystemBase extends Subsystem {}

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/SwerveControllerCommand.java

@@ -31,7 +31,7 @@ import java.util.function.Supplier;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public class SwerveControllerCommand extends CommandBase {
+public class SwerveControllerCommand extends Command {
   private final Timer m_timer = new Timer();
   private final Trajectory m_trajectory;
   private final Supplier<Pose2d> m_pose;

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/TrapezoidProfileCommand.java

@@ -16,7 +16,7 @@ import java.util.function.Consumer;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public class TrapezoidProfileCommand extends CommandBase {
+public class TrapezoidProfileCommand extends Command {
   private final TrapezoidProfile m_profile;
   private final Consumer<State> m_output;
 

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/TrapezoidProfileSubsystem.java

@@ -14,7 +14,7 @@ import edu.wpi.first.math.trajectory.TrapezoidProfile;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public abstract class TrapezoidProfileSubsystem extends SubsystemBase {
+public abstract class TrapezoidProfileSubsystem extends Subsystem {
   private final double m_period;
   private final TrapezoidProfile.Constraints m_constraints;
 

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/WaitCommand.java

@@ -13,7 +13,7 @@ import edu.wpi.first.wpilibj.Timer;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public class WaitCommand extends CommandBase {
+public class WaitCommand extends Command {
   protected Timer m_timer = new Timer();
   private final double m_duration;
 

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/WaitUntilCommand.java

@@ -15,7 +15,7 @@ import java.util.function.BooleanSupplier;
  *
  * <p>This class is provided by the NewCommands VendorDep
  */
-public class WaitUntilCommand extends CommandBase {
+public class WaitUntilCommand extends Command {
   private final BooleanSupplier m_condition;
 
   /**

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/WrapperCommand.java

@@ -14,7 +14,7 @@ import java.util.Set;
  * added to any other composition or scheduled individually, and the composition requires all
  * subsystems its components require.
  */
-public abstract class WrapperCommand extends CommandBase {
+public abstract class WrapperCommand extends Command {
   protected final Command m_command;
 
   /**

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.

wpilibNewCommands/src/test/java/edu/wpi/first/wpilibj2/command/CommandRequirementsTest.java

@@ -15,7 +15,7 @@ class CommandRequirementsTest extends CommandTestBase {
   @Test
   void requirementInterruptTest() {
     try (CommandScheduler scheduler = new CommandScheduler()) {
-      Subsystem requirement = new SubsystemBase() {};
+      Subsystem requirement = new Subsystem() {};
 
       MockCommandHolder interruptedHolder = new MockCommandHolder(true, requirement);
       Command interrupted = interruptedHolder.getMock();
@@ -42,7 +42,7 @@ class CommandRequirementsTest extends CommandTestBase {
   @Test
   void requirementUninterruptibleTest() {
     try (CommandScheduler scheduler = new CommandScheduler()) {
-      Subsystem requirement = new SubsystemBase() {};
+      Subsystem requirement = new Subsystem() {};
 
       Command notInterrupted =
           new RunCommand(() -> {}, requirement)
@@ -61,7 +61,7 @@ class CommandRequirementsTest extends CommandTestBase {
   @Test
   void defaultCommandRequirementErrorTest() {
     try (CommandScheduler scheduler = new CommandScheduler()) {
-      Subsystem system = new SubsystemBase() {};
+      Subsystem system = new Subsystem() {};
 
       Command missingRequirement = new WaitUntilCommand(() -> false);
 

wpilibNewCommands/src/test/java/edu/wpi/first/wpilibj2/command/CommandSendableButtonTest.java

@@ -21,7 +21,7 @@ class CommandSendableButtonTest extends CommandTestBase {
   private AtomicInteger m_schedule;
   private AtomicInteger m_cancel;
   private BooleanPublisher m_publish;
-  private CommandBase m_command;
+  private Command m_command;
 
   @BeforeEach
   void setUp() {

wpilibNewCommands/src/test/java/edu/wpi/first/wpilibj2/command/CommandTestBase.java

@@ -23,6 +23,7 @@ public class CommandTestBase {
     CommandScheduler.getInstance().enable();
     CommandScheduler.getInstance().getActiveButtonLoop().clear();
     CommandScheduler.getInstance().clearComposedCommands();
+    CommandScheduler.getInstance().unregisterAllSubsystems();
 
     setDSEnabled(true);
   }

wpilibNewCommands/src/test/java/edu/wpi/first/wpilibj2/command/ConditionalCommandTest.java

@@ -46,9 +46,9 @@ class ConditionalCommandTest extends CommandTestBase {
 
   @Test
   void conditionalCommandRequirementTest() {
-    Subsystem system1 = new SubsystemBase() {};
-    Subsystem system2 = new SubsystemBase() {};
-    Subsystem system3 = new SubsystemBase() {};
+    Subsystem system1 = new Subsystem() {};
+    Subsystem system2 = new Subsystem() {};
+    Subsystem system3 = new Subsystem() {};
 
     try (CommandScheduler scheduler = new CommandScheduler()) {
       MockCommandHolder command1Holder = new MockCommandHolder(true, system1, system2);

wpilibNewCommands/src/test/java/edu/wpi/first/wpilibj2/command/DefaultCommandTest.java

@@ -14,7 +14,7 @@ class DefaultCommandTest extends CommandTestBase {
   @Test
   void defaultCommandScheduleTest() {
     try (CommandScheduler scheduler = new CommandScheduler()) {
-      Subsystem hasDefaultCommand = new SubsystemBase() {};
+      Subsystem hasDefaultCommand = new Subsystem() {};
 
       MockCommandHolder defaultHolder = new MockCommandHolder(true, hasDefaultCommand);
       Command defaultCommand = defaultHolder.getMock();
@@ -29,7 +29,7 @@ class DefaultCommandTest extends CommandTestBase {
   @Test
   void defaultCommandInterruptResumeTest() {
     try (CommandScheduler scheduler = new CommandScheduler()) {
-      Subsystem hasDefaultCommand = new SubsystemBase() {};
+      Subsystem hasDefaultCommand = new Subsystem() {};
 
       MockCommandHolder defaultHolder = new MockCommandHolder(true, hasDefaultCommand);
       Command defaultCommand = defaultHolder.getMock();
@@ -54,7 +54,7 @@ class DefaultCommandTest extends CommandTestBase {
   @Test
   void defaultCommandDisableResumeTest() {
     try (CommandScheduler scheduler = new CommandScheduler()) {
-      Subsystem hasDefaultCommand = new SubsystemBase() {};
+      Subsystem hasDefaultCommand = new Subsystem() {};
 
       MockCommandHolder defaultHolder = new MockCommandHolder(false, hasDefaultCommand);
       Command defaultCommand = defaultHolder.getMock();

wpilibNewCommands/src/test/java/edu/wpi/first/wpilibj2/command/ParallelCommandGroupTest.java

@@ -90,10 +90,10 @@ class ParallelCommandGroupTest extends CommandTestBase
 
   @Test
   void parallelGroupRequirementTest() {
-    Subsystem system1 = new SubsystemBase() {};
-    Subsystem system2 = new SubsystemBase() {};
-    Subsystem system3 = new SubsystemBase() {};
-    Subsystem system4 = new SubsystemBase() {};
+    Subsystem system1 = new Subsystem() {};
+    Subsystem system2 = new Subsystem() {};
+    Subsystem system3 = new Subsystem() {};
+    Subsystem system4 = new Subsystem() {};
 
     try (CommandScheduler scheduler = new CommandScheduler()) {
       MockCommandHolder command1Holder = new MockCommandHolder(true, system1, system2);
@@ -115,9 +115,9 @@ class ParallelCommandGroupTest extends CommandTestBase
 
   @Test
   void parallelGroupRequirementErrorTest() {
-    Subsystem system1 = new SubsystemBase() {};
-    Subsystem system2 = new SubsystemBase() {};
-    Subsystem system3 = new SubsystemBase() {};
+    Subsystem system1 = new Subsystem() {};
+    Subsystem system2 = new Subsystem() {};
+    Subsystem system3 = new Subsystem() {};
 
     MockCommandHolder command1Holder = new MockCommandHolder(true, system1, system2);
     Command command1 = command1Holder.getMock();

wpilibNewCommands/src/test/java/edu/wpi/first/wpilibj2/command/ParallelDeadlineGroupTest.java

@@ -87,10 +87,10 @@ class ParallelDeadlineGroupTest extends CommandTestBase
 
   @Test
   void parallelDeadlineRequirementTest() {
-    Subsystem system1 = new SubsystemBase() {};
-    Subsystem system2 = new SubsystemBase() {};
-    Subsystem system3 = new SubsystemBase() {};
-    Subsystem system4 = new SubsystemBase() {};
+    Subsystem system1 = new Subsystem() {};
+    Subsystem system2 = new Subsystem() {};
+    Subsystem system3 = new Subsystem() {};
+    Subsystem system4 = new Subsystem() {};
 
     try (CommandScheduler scheduler = new CommandScheduler()) {
       MockCommandHolder command1Holder = new MockCommandHolder(true, system1, system2);
@@ -112,9 +112,9 @@ class ParallelDeadlineGroupTest extends CommandTestBase
 
   @Test
   void parallelDeadlineRequirementErrorTest() {
-    Subsystem system1 = new SubsystemBase() {};
-    Subsystem system2 = new SubsystemBase() {};
-    Subsystem system3 = new SubsystemBase() {};
+    Subsystem system1 = new Subsystem() {};
+    Subsystem system2 = new Subsystem() {};
+    Subsystem system3 = new Subsystem() {};
 
     MockCommandHolder command1Holder = new MockCommandHolder(true, system1, system2);
     Command command1 = command1Holder.getMock();

wpilibNewCommands/src/test/java/edu/wpi/first/wpilibj2/command/ParallelRaceGroupTest.java

@@ -92,10 +92,10 @@ class ParallelRaceGroupTest extends CommandTestBase
 
   @Test
   void parallelRaceRequirementTest() {
-    Subsystem system1 = new SubsystemBase() {};
-    Subsystem system2 = new SubsystemBase() {};
-    Subsystem system3 = new SubsystemBase() {};
-    Subsystem system4 = new SubsystemBase() {};
+    Subsystem system1 = new Subsystem() {};
+    Subsystem system2 = new Subsystem() {};
+    Subsystem system3 = new Subsystem() {};
+    Subsystem system4 = new Subsystem() {};
 
     try (CommandScheduler scheduler = new CommandScheduler()) {
       MockCommandHolder command1Holder = new MockCommandHolder(true, system1, system2);
@@ -117,9 +117,9 @@ class ParallelRaceGroupTest extends CommandTestBase
 
   @Test
   void parallelRaceRequirementErrorTest() {
-    Subsystem system1 = new SubsystemBase() {};
-    Subsystem system2 = new SubsystemBase() {};
-    Subsystem system3 = new SubsystemBase() {};
+    Subsystem system1 = new Subsystem() {};
+    Subsystem system2 = new Subsystem() {};
+    Subsystem system3 = new Subsystem() {};
 
     MockCommandHolder command1Holder = new MockCommandHolder(true, system1, system2);
     Command command1 = command1Holder.getMock();
@@ -131,8 +131,8 @@ class ParallelRaceGroupTest extends CommandTestBase
 
   @Test
   void parallelRaceOnlyCallsEndOnceTest() {
-    Subsystem system1 = new SubsystemBase() {};
-    Subsystem system2 = new SubsystemBase() {};
+    Subsystem system1 = new Subsystem() {};
+    Subsystem system2 = new Subsystem() {};
 
     MockCommandHolder command1Holder = new MockCommandHolder(true, system1);
     Command command1 = command1Holder.getMock();

wpilibNewCommands/src/test/java/edu/wpi/first/wpilibj2/command/SchedulerTest.java

@@ -48,7 +48,7 @@ class SchedulerTest extends CommandTestBase {
     try (CommandScheduler scheduler = new CommandScheduler()) {
       AtomicInteger counter = new AtomicInteger(0);
       Subsystem system =
-          new SubsystemBase() {
+          new Subsystem() {
             @Override
             public void periodic() {
               counter.incrementAndGet();
@@ -67,7 +67,7 @@ class SchedulerTest extends CommandTestBase {
     try (CommandScheduler scheduler = new CommandScheduler()) {
       AtomicInteger counter = new AtomicInteger(0);
       Subsystem system =
-          new SubsystemBase() {
+          new Subsystem() {
             @Override
             public void periodic() {
               counter.incrementAndGet();

wpilibNewCommands/src/test/java/edu/wpi/first/wpilibj2/command/SchedulingRecursionTest.java

@@ -25,9 +25,9 @@ class SchedulingRecursionTest extends CommandTestBase {
   void cancelFromInitialize(InterruptionBehavior interruptionBehavior) {
     try (CommandScheduler scheduler = new CommandScheduler()) {
       AtomicBoolean hasOtherRun = new AtomicBoolean();
-      Subsystem requirement = new SubsystemBase() {};
+      Subsystem requirement = new Subsystem() {};
       Command selfCancels =
-          new CommandBase() {
+          new Command() {
             {
               addRequirements(requirement);
             }
@@ -62,9 +62,9 @@ class SchedulingRecursionTest extends CommandTestBase {
   void defaultCommandGetsRescheduledAfterSelfCanceling(InterruptionBehavior interruptionBehavior) {
     try (CommandScheduler scheduler = new CommandScheduler()) {
       AtomicBoolean hasOtherRun = new AtomicBoolean();
-      Subsystem requirement = new SubsystemBase() {};
+      Subsystem requirement = new Subsystem() {};
       Command selfCancels =
-          new CommandBase() {
+          new Command() {
             {
               addRequirements(requirement);
             }
@@ -100,7 +100,7 @@ class SchedulingRecursionTest extends CommandTestBase {
     try (CommandScheduler scheduler = new CommandScheduler()) {
       AtomicInteger counter = new AtomicInteger();
       Command selfCancels =
-          new CommandBase() {
+          new Command() {
             @Override
             public void end(boolean interrupted) {
               counter.incrementAndGet();
@@ -119,10 +119,10 @@ class SchedulingRecursionTest extends CommandTestBase {
   void scheduleFromEndCancel() {
     try (CommandScheduler scheduler = new CommandScheduler()) {
       AtomicInteger counter = new AtomicInteger();
-      Subsystem requirement = new SubsystemBase() {};
+      Subsystem requirement = new Subsystem() {};
       InstantCommand other = new InstantCommand(() -> {}, requirement);
       Command selfCancels =
-          new CommandBase() {
+          new Command() {
             {
               addRequirements(requirement);
             }
@@ -146,10 +146,10 @@ class SchedulingRecursionTest extends CommandTestBase {
   void scheduleFromEndInterrupt() {
     try (CommandScheduler scheduler = new CommandScheduler()) {
       AtomicInteger counter = new AtomicInteger();
-      Subsystem requirement = new SubsystemBase() {};
+      Subsystem requirement = new Subsystem() {};
       InstantCommand other = new InstantCommand(() -> {}, requirement);
       Command selfCancels =
-          new CommandBase() {
+          new Command() {
             {
               addRequirements(requirement);
             }
@@ -175,11 +175,11 @@ class SchedulingRecursionTest extends CommandTestBase {
   void scheduleInitializeFromDefaultCommand(InterruptionBehavior interruptionBehavior) {
     try (CommandScheduler scheduler = new CommandScheduler()) {
       AtomicInteger counter = new AtomicInteger();
-      Subsystem requirement = new SubsystemBase() {};
+      Subsystem requirement = new Subsystem() {};
       Command other =
           new InstantCommand(() -> {}, requirement).withInterruptBehavior(interruptionBehavior);
       Command defaultCommand =
-          new CommandBase() {
+          new Command() {
             {
               addRequirements(requirement);
             }

wpilibNewCommands/src/test/java/edu/wpi/first/wpilibj2/command/SelectCommandTest.java

@@ -75,10 +75,10 @@ class SelectCommandTest extends CommandTestBase implements MultiCompositionTestB
 
   @Test
   void selectCommandRequirementTest() {
-    Subsystem system1 = new SubsystemBase() {};
-    Subsystem system2 = new SubsystemBase() {};
-    Subsystem system3 = new SubsystemBase() {};
-    Subsystem system4 = new SubsystemBase() {};
+    Subsystem system1 = new Subsystem() {};
+    Subsystem system2 = new Subsystem() {};
+    Subsystem system3 = new Subsystem() {};
+    Subsystem system4 = new Subsystem() {};
 
     try (CommandScheduler scheduler = new CommandScheduler()) {
       MockCommandHolder command1Holder = new MockCommandHolder(true, system1, system2);

wpilibNewCommands/src/test/java/edu/wpi/first/wpilibj2/command/SequentialCommandGroupTest.java

@@ -100,10 +100,10 @@ class SequentialCommandGroupTest extends CommandTestBase
 
   @Test
   void sequentialGroupRequirementTest() {
-    Subsystem system1 = new SubsystemBase() {};
-    Subsystem system2 = new SubsystemBase() {};
-    Subsystem system3 = new SubsystemBase() {};
-    Subsystem system4 = new SubsystemBase() {};
+    Subsystem system1 = new Subsystem() {};
+    Subsystem system2 = new Subsystem() {};
+    Subsystem system3 = new Subsystem() {};
+    Subsystem system4 = new Subsystem() {};
 
     try (CommandScheduler scheduler = new CommandScheduler()) {
       MockCommandHolder command1Holder = new MockCommandHolder(true, system1, system2);

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

@@ -11,12 +11,14 @@ CommandTestBase::CommandTestBase() {
   scheduler.CancelAll();
   scheduler.Enable();
   scheduler.GetActiveButtonLoop()->Clear();
+  scheduler.UnregisterAllSubsystems();
 
   SetDSEnabled(true);
 }
 
 CommandTestBase::~CommandTestBase() {
   CommandScheduler::GetInstance().GetActiveButtonLoop()->Clear();
+  CommandScheduler::GetInstance().UnregisterAllSubsystems();
 }
 
 CommandScheduler CommandTestBase::GetScheduler() {

wpilibNewCommands/src/test/native/cpp/frc2/command/CommandTestBase.h

@@ -12,14 +12,14 @@
 #include "frc2/command/CommandHelper.h"
 #include "frc2/command/CommandScheduler.h"
 #include "frc2/command/SetUtilities.h"
-#include "frc2/command/SubsystemBase.h"
+#include "frc2/command/Subsystem.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 #include "make_vector.h"
 
 namespace frc2 {
 
-class TestSubsystem : public SubsystemBase {
+class TestSubsystem : public Subsystem {
  public:
   explicit TestSubsystem(std::function<void()> periodic = [] {})
       : m_periodic{periodic} {}
@@ -32,7 +32,7 @@ class TestSubsystem : public SubsystemBase {
 /**
  * NOTE: Moving mock objects causes EXPECT_CALL to not work correctly!
  */
-class MockCommand : public CommandHelper<CommandBase, MockCommand> {
+class MockCommand : public CommandHelper<Command, MockCommand> {
  public:
   MOCK_CONST_METHOD0(GetRequirements, wpi::SmallSet<Subsystem*, 4>());
   MOCK_METHOD0(IsFinished, bool());
@@ -107,12 +107,14 @@ class CommandTestBaseWithParam : public ::testing::TestWithParam<T> {
     scheduler.CancelAll();
     scheduler.Enable();
     scheduler.GetActiveButtonLoop()->Clear();
+    scheduler.UnregisterAllSubsystems();
 
     SetDSEnabled(true);
   }
 
   ~CommandTestBaseWithParam() override {
     CommandScheduler::GetInstance().GetActiveButtonLoop()->Clear();
+    CommandScheduler::GetInstance().UnregisterAllSubsystems();
   }
 
  protected:

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

@@ -17,6 +17,7 @@
 #include <frc/simulation/SimHooks.h>
 #include <frc/trajectory/TrajectoryGenerator.h>
 
+#include "CommandTestBase.h"
 #include "gtest/gtest.h"
 
 #define EXPECT_NEAR_UNITS(val1, val2, eps) \
@@ -87,7 +88,7 @@ class MecanumControllerCommandTest : public ::testing::Test {
 };
 
 TEST_F(MecanumControllerCommandTest, ReachesReference) {
-  frc2::Subsystem subsystem;
+  frc2::TestSubsystem subsystem;
 
   auto waypoints =
       std::vector{frc::Pose2d{0_m, 0_m, 0_rad}, frc::Pose2d{1_m, 5_m, 3_rad}};

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

@@ -14,7 +14,7 @@ class SchedulingRecursionTest
     : public CommandTestBaseWithParam<Command::InterruptionBehavior> {};
 
 class SelfCancellingCommand
-    : public CommandHelper<CommandBase, SelfCancellingCommand> {
+    : public CommandHelper<Command, SelfCancellingCommand> {
  public:
   SelfCancellingCommand(CommandScheduler* scheduler, Subsystem* requirement,
                         Command::InterruptionBehavior interruptionBehavior =
@@ -76,7 +76,7 @@ TEST_P(SchedulingRecursionTest,
   EXPECT_TRUE(hasOtherRun);
 }
 
-class CancelEndCommand : public CommandHelper<CommandBase, CancelEndCommand> {
+class CancelEndCommand : public CommandHelper<Command, CancelEndCommand> {
  public:
   CancelEndCommand(CommandScheduler* scheduler, int& counter)
       : m_scheduler(scheduler), m_counter(counter) {}

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

@@ -18,6 +18,7 @@
 #include <frc/simulation/SimHooks.h>
 #include <frc/trajectory/TrajectoryGenerator.h>
 
+#include "CommandTestBase.h"
 #include "gtest/gtest.h"
 
 #define EXPECT_NEAR_UNITS(val1, val2, eps) \
@@ -72,7 +73,7 @@ class SwerveControllerCommandTest : public ::testing::Test {
 };
 
 TEST_F(SwerveControllerCommandTest, ReachesReference) {
-  frc2::Subsystem subsystem;
+  frc2::TestSubsystem subsystem;
 
   auto waypoints =
       std::vector{frc::Pose2d{0_m, 0_m, 0_rad}, frc::Pose2d{1_m, 5_m, 3_rad}};

wpilibcExamples/src/main/cpp/commands/command2/ReplaceMeCommand2.h

@@ -4,18 +4,18 @@
 
 #pragma once
 
-#include <frc2/command/CommandBase.h>
+#include <frc2/command/Command.h>
 #include <frc2/command/CommandHelper.h>
 
 /**
  * An example command.
  *
- * <p>Note that this extends CommandHelper, rather extending CommandBase
+ * <p>Note that this extends CommandHelper, rather extending Command
  * directly; this is crucially important, or else the decorator functions in
  * Command will *not* work!
  */
 class ReplaceMeCommand2
-    : public frc2::CommandHelper<frc2::CommandBase, ReplaceMeCommand2> {
+    : public frc2::CommandHelper<frc2::Command, ReplaceMeCommand2> {
  public:
   ReplaceMeCommand2();
 

wpilibcExamples/src/main/cpp/commands/subsystem2/ReplaceMeSubsystem2.h

@@ -4,9 +4,9 @@
 
 #pragma once
 
-#include <frc2/command/SubsystemBase.h>
+#include <frc2/command/Subsystem.h>
 
-class ReplaceMeSubsystem2 : public frc2::SubsystemBase {
+class ReplaceMeSubsystem2 : public frc2::Subsystem {
  public:
   ReplaceMeSubsystem2();
 

wpilibcExamples/src/main/cpp/examples/ArmBot/include/subsystems/DriveSubsystem.h

@@ -8,11 +8,11 @@
 #include <frc/drive/DifferentialDrive.h>
 #include <frc/motorcontrol/MotorControllerGroup.h>
 #include <frc/motorcontrol/PWMSparkMax.h>
-#include <frc2/command/SubsystemBase.h>
+#include <frc2/command/Subsystem.h>
 
 #include "Constants.h"
 
-class DriveSubsystem : public frc2::SubsystemBase {
+class DriveSubsystem : public frc2::Subsystem {
  public:
   DriveSubsystem();
 

wpilibcExamples/src/main/cpp/examples/ArmBotOffboard/include/subsystems/DriveSubsystem.h

@@ -11,11 +11,11 @@
 #include <frc/motorcontrol/MotorControllerGroup.h>
 #include <frc/motorcontrol/PWMSparkMax.h>
 #include <frc2/command/Commands.h>
-#include <frc2/command/SubsystemBase.h>
+#include <frc2/command/Subsystem.h>
 
 #include "Constants.h"
 
-class DriveSubsystem : public frc2::SubsystemBase {
+class DriveSubsystem : public frc2::Subsystem {
  public:
   DriveSubsystem();
 

wpilibcExamples/src/main/cpp/examples/DriveDistanceOffboard/include/subsystems/DriveSubsystem.h

@@ -8,13 +8,13 @@
 #include <frc/controller/SimpleMotorFeedforward.h>
 #include <frc/drive/DifferentialDrive.h>
 #include <frc/trajectory/TrapezoidProfile.h>
-#include <frc2/command/SubsystemBase.h>
+#include <frc2/command/Subsystem.h>
 #include <units/length.h>
 
 #include "Constants.h"
 #include "ExampleSmartMotorController.h"
 
-class DriveSubsystem : public frc2::SubsystemBase {
+class DriveSubsystem : public frc2::Subsystem {
  public:
   DriveSubsystem();
 

wpilibcExamples/src/main/cpp/examples/Frisbeebot/include/subsystems/DriveSubsystem.h

@@ -8,11 +8,11 @@
 #include <frc/drive/DifferentialDrive.h>
 #include <frc/motorcontrol/MotorControllerGroup.h>
 #include <frc/motorcontrol/PWMSparkMax.h>
-#include <frc2/command/SubsystemBase.h>
+#include <frc2/command/Subsystem.h>
 
 #include "Constants.h"
 
-class DriveSubsystem : public frc2::SubsystemBase {
+class DriveSubsystem : public frc2::Subsystem {
  public:
   DriveSubsystem();
 

wpilibcExamples/src/main/cpp/examples/GearsBot/include/commands/CloseClaw.h

@@ -4,7 +4,7 @@
 
 #pragma once
 
-#include <frc2/command/CommandBase.h>
+#include <frc2/command/Command.h>
 #include <frc2/command/CommandHelper.h>
 
 #include "subsystems/Claw.h"
@@ -12,7 +12,7 @@
 /**
  * Closes the claw until the limit switch is tripped.
  */
-class CloseClaw : public frc2::CommandHelper<frc2::CommandBase, CloseClaw> {
+class CloseClaw : public frc2::CommandHelper<frc2::Command, CloseClaw> {
  public:
   explicit CloseClaw(Claw& claw);
   void Initialize() override;

wpilibcExamples/src/main/cpp/examples/GearsBot/include/commands/SetElevatorSetpoint.h

@@ -4,7 +4,7 @@
 
 #pragma once
 
-#include <frc2/command/CommandBase.h>
+#include <frc2/command/Command.h>
 #include <frc2/command/CommandHelper.h>
 
 #include "subsystems/Elevator.h"
@@ -17,7 +17,7 @@
  * commands using the elevator should make sure they disable PID!
  */
 class SetElevatorSetpoint
-    : public frc2::CommandHelper<frc2::CommandBase, SetElevatorSetpoint> {
+    : public frc2::CommandHelper<frc2::Command, SetElevatorSetpoint> {
  public:
   explicit SetElevatorSetpoint(double setpoint, Elevator& elevator);
   void Initialize() override;

wpilibcExamples/src/main/cpp/examples/GearsBot/include/commands/SetWristSetpoint.h

@@ -4,7 +4,7 @@
 
 #pragma once
 
-#include <frc2/command/CommandBase.h>
+#include <frc2/command/Command.h>
 #include <frc2/command/CommandHelper.h>
 
 #include "subsystems/Wrist.h"
@@ -15,7 +15,7 @@
  * Other commands using the wrist should make sure they disable PID!
  */
 class SetWristSetpoint
-    : public frc2::CommandHelper<frc2::CommandBase, SetWristSetpoint> {
+    : public frc2::CommandHelper<frc2::Command, SetWristSetpoint> {
  public:
   explicit SetWristSetpoint(double setpoint, Wrist& wrist);
   void Initialize() override;

wpilibcExamples/src/main/cpp/examples/GearsBot/include/commands/TankDrive.h

@@ -4,7 +4,7 @@
 
 #pragma once
 
-#include <frc2/command/CommandBase.h>
+#include <frc2/command/Command.h>
 #include <frc2/command/CommandHelper.h>
 
 #include "subsystems/Drivetrain.h"
@@ -12,7 +12,7 @@
 /**
  * Have the robot drive tank style using the PS3 Joystick until interrupted.
  */
-class TankDrive : public frc2::CommandHelper<frc2::CommandBase, TankDrive> {
+class TankDrive : public frc2::CommandHelper<frc2::Command, TankDrive> {
  public:
   TankDrive(std::function<double()> left, std::function<double()> right,
             Drivetrain& drivetrain);

wpilibcExamples/src/main/cpp/examples/GearsBot/include/subsystems/Claw.h

@@ -6,14 +6,14 @@
 
 #include <frc/DigitalInput.h>
 #include <frc/motorcontrol/PWMSparkMax.h>
-#include <frc2/command/SubsystemBase.h>
+#include <frc2/command/Subsystem.h>
 
 /**
  * The claw subsystem is a simple system with a motor for opening and closing.
  * If using stronger motors, you should probably use a sensor so that the
  * motors don't stall.
  */
-class Claw : public frc2::SubsystemBase {
+class Claw : public frc2::Subsystem {
  public:
   Claw();
 

wpilibcExamples/src/main/cpp/examples/GearsBot/include/subsystems/Drivetrain.h

@@ -10,7 +10,7 @@
 #include <frc/drive/DifferentialDrive.h>
 #include <frc/motorcontrol/MotorControllerGroup.h>
 #include <frc/motorcontrol/PWMSparkMax.h>
-#include <frc2/command/SubsystemBase.h>
+#include <frc2/command/Subsystem.h>
 
 namespace frc {
 class Joystick;
@@ -21,7 +21,7 @@ class Joystick;
  * the robots chassis. These include four drive motors, a left and right encoder
  * and a gyro.
  */
-class Drivetrain : public frc2::SubsystemBase {
+class Drivetrain : public frc2::Subsystem {
  public:
   Drivetrain();