[commands] Undeprecate deferredProxy (#7417)

This changes the way deferred proxy is implemented to not use the
deprecated ProxyCommand constructor.

This function serves a good purpose that should be kept IMO. The
constructor was confusing but this is just good syntactic sugar over
`defer(() -> supplier.get().asProxy())`.

Signed-off-by: Jade Turner <spacey-sooty@proton.me>

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

@@ -198,15 +198,11 @@ public final class Commands {
    *
    * @param supplier the command supplier
    * @return the command
-   * @deprecated The ProxyCommand supplier constructor has been deprecated in favor of directly
-   *     proxying a {@link DeferredCommand}, see ProxyCommand documentation for more details. As a
-   *     replacement, consider using `defer(supplier).asProxy()`.
    * @see ProxyCommand
+   * @see DeferredCommand
    */
-  @Deprecated(since = "2025", forRemoval = true)
-  @SuppressWarnings("removal")
   public static Command deferredProxy(Supplier<Command> supplier) {
-    return new ProxyCommand(supplier);
+    return defer(() -> supplier.get().asProxy(), Set.of());
   }
 
   // Command Groups

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

@@ -7,6 +7,7 @@
 #include <utility>
 #include <vector>
 
+#include <wpi/FunctionExtras.h>
 #include <wpi/deprecated.h>
 
 #include "frc2/command/ConditionalCommand.h"
@@ -73,15 +74,21 @@ CommandPtr cmd::Print(std::string_view msg) {
   return PrintCommand(msg).ToPtr();
 }
 
-WPI_IGNORE_DEPRECATED
 CommandPtr cmd::DeferredProxy(wpi::unique_function<Command*()> supplier) {
-  return ProxyCommand(std::move(supplier)).ToPtr();
+  return Defer(
+      [supplier = std::move(supplier)]() mutable {
+        // There is no non-owning version of AsProxy(), so use the non-owning
+        // ProxyCommand constructor instead.
+        return ProxyCommand{supplier()}.ToPtr();
+      },
+      {});
 }
 
 CommandPtr cmd::DeferredProxy(wpi::unique_function<CommandPtr()> supplier) {
-  return ProxyCommand(std::move(supplier)).ToPtr();
+  return Defer([supplier = std::move(
+                    supplier)]() mutable { return supplier().AsProxy(); },
+               {});
 }
-WPI_UNIGNORE_DEPRECATED
 
 CommandPtr cmd::Wait(units::second_t duration) {
   return WaitCommand(duration).ToPtr();

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

@@ -169,15 +169,11 @@ CommandPtr Defer(wpi::unique_function<CommandPtr()> supplier,
 /**
  * Constructs a command that schedules the command returned from the supplier
  * when initialized, and ends when it is no longer scheduled. The supplier is
- * called when the command is initialized. As a replacement, consider using
- * `Defer(supplier).AsProxy()`.
+ * called when the command is initialized.
  *
  * @param supplier the command supplier
  */
-WPI_IGNORE_DEPRECATED
-[[nodiscard]] [[deprecated(
-    "The ProxyCommand supplier constructor has been deprecated. Use "
-    "Defer(supplier).AsProxy() instead.")]]
+[[nodiscard]]
 CommandPtr DeferredProxy(wpi::unique_function<Command*()> supplier);
 
 /**
@@ -187,11 +183,8 @@ CommandPtr DeferredProxy(wpi::unique_function<Command*()> supplier);
  *
  * @param supplier the command supplier
  */
-[[nodiscard]] [[deprecated(
-    "The ProxyCommand supplier constructor has been deprecated. Use "
-    "Defer(supplier).AsProxy() instead.")]]
+[[nodiscard]]
 CommandPtr DeferredProxy(wpi::unique_function<CommandPtr()> supplier);
-WPI_UNIGNORE_DEPRECATED
 // Command Groups
 
 namespace impl {