[wpimath] Add structured data support for DifferentialDriveWheelPositions (#6412)

wpimath/src/test/java/edu/wpi/first/math/kinematics/struct/DifferentialDriveWheelPositionsStructTest.java

@@ -0,0 +1,29 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+package edu.wpi.first.math.kinematics.struct;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import edu.wpi.first.math.kinematics.DifferentialDriveWheelPositions;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import org.junit.jupiter.api.Test;
+
+class DifferentialDriveWheelPositionsStructTest {
+  private static final DifferentialDriveWheelPositions DATA =
+      new DifferentialDriveWheelPositions(1.74, 35.04);
+
+  @Test
+  void testRoundtrip() {
+    ByteBuffer buffer = ByteBuffer.allocate(DifferentialDriveWheelPositions.struct.getSize());
+    buffer.order(ByteOrder.LITTLE_ENDIAN);
+    DifferentialDriveWheelPositions.struct.pack(buffer, DATA);
+    buffer.rewind();
+
+    DifferentialDriveWheelPositions data = DifferentialDriveWheelPositions.struct.unpack(buffer);
+    assertEquals(DATA.leftMeters, data.leftMeters);
+    assertEquals(DATA.rightMeters, data.rightMeters);
+  }
+}