[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);
+  }
+}

wpimath/src/test/native/cpp/kinematics/struct/DifferentialDriveWheelPositionsStructTest.cpp

@@ -0,0 +1,27 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#include <gtest/gtest.h>
+
+#include "frc/kinematics/DifferentialDriveWheelPositions.h"
+
+using namespace frc;
+
+namespace {
+
+using StructType = wpi::Struct<frc::DifferentialDriveWheelPositions>;
+const DifferentialDriveWheelPositions kExpectedData{
+    DifferentialDriveWheelPositions{1.74_m, 35.04_m}};
+}  // namespace
+
+TEST(DifferentialDriveWheelPositionsStructTest, Roundtrip) {
+  uint8_t buffer[StructType::GetSize()];
+  std::memset(buffer, 0, StructType::GetSize());
+  StructType::Pack(buffer, kExpectedData);
+
+  DifferentialDriveWheelPositions unpacked_data = StructType::Unpack(buffer);
+
+  EXPECT_EQ(kExpectedData.left.value(), unpacked_data.left.value());
+  EXPECT_EQ(kExpectedData.right.value(), unpacked_data.right.value());
+}