[wpilib] Fix PowerDistribution.GetAllCurrents() (#6025)

wpilibj/src/main/java/edu/wpi/first/wpilibj/PowerDistribution.java

@@ -113,6 +113,17 @@ public class PowerDistribution implements Sendable, AutoCloseable {
     return PowerDistributionJNI.getChannelCurrent(m_handle, channel);
   }
 
+  /**
+   * Query all currents of the PDP.
+   *
+   * @return The current of each channel in Amperes
+   */
+  public double[] getAllCurrents() {
+    double[] currents = new double[getNumChannels()];
+    PowerDistributionJNI.getAllCurrents(m_handle, currents);
+    return currents;
+  }
+
   /**
    * Query the current of all monitored channels.
    *

wpilibj/src/test/java/edu/wpi/first/wpilibj/PowerDistributionTest.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.wpilibj;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import edu.wpi.first.hal.HAL;
+import edu.wpi.first.wpilibj.PowerDistribution.ModuleType;
+import edu.wpi.first.wpilibj.simulation.PDPSim;
+import org.junit.jupiter.api.Test;
+
+class PowerDistributionTest {
+  @Test
+  void testGetAllCurrents() {
+    HAL.initialize(500, 0);
+    PowerDistribution pdp = new PowerDistribution(1, ModuleType.kRev);
+    PDPSim sim = new PDPSim(pdp);
+
+    for (int i = 0; i < pdp.getNumChannels(); i++) {
+      sim.setCurrent(i, 24 - i);
+    }
+    double[] currents = pdp.getAllCurrents();
+    for (int i = 0; i < pdp.getNumChannels(); i++) {
+      assertEquals(24 - i, currents[i]);
+    }
+  }
+}