Convert UnitTestUtility to a JUnit 5 MockHardwareExtension (#1153)

Only initialize the HAL once.

shared/java/javacommon.gradle

@@ -80,6 +80,7 @@ publishing {
 
 test {
     useJUnitPlatform()
+    systemProperty 'junit.jupiter.extensions.autodetection.enabled', 'true'
     testLogging {
         events "failed"
         exceptionFormat "full"

wpilibj/src/test/java/edu/wpi/first/wpilibj/CircularBufferTest.java

@@ -7,7 +7,6 @@
 
 package edu.wpi.first.wpilibj;
 
-import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -20,11 +19,6 @@ class CircularBufferTest {
   private final double[] m_addLastOut = {342.657, 234.252, 716.126, 132.344, 445.697,
       22.727, 421.125, 799.913};
 
-  @BeforeAll
-  static void before() {
-    UnitTestUtility.setupMockBase();
-  }
-
   @Test
   void addFirstTest() {
     CircularBuffer queue = new CircularBuffer(8);

wpilibj/src/test/java/edu/wpi/first/wpilibj/MockHardwareExtension.java

@@ -11,21 +11,27 @@ import java.util.concurrent.TimeUnit;
 
 import com.google.common.base.Stopwatch;
 
+import org.junit.jupiter.api.extension.BeforeAllCallback;
+import org.junit.jupiter.api.extension.ExtensionContext;
+import org.junit.jupiter.api.extension.ExtensionContext.Namespace;
+
 import edu.wpi.first.wpilibj.hal.HAL;
 import edu.wpi.first.wpilibj.util.BaseSystemNotInitializedException;
 
-/**
- * Utility class for configuring unit tests.
- */
-public final class UnitTestUtility {
-  private UnitTestUtility() {
-        /* no-op */
+public final class MockHardwareExtension implements BeforeAllCallback {
+  private static ExtensionContext getRoot(ExtensionContext context) {
+    return context.getParent().map(MockHardwareExtension::getRoot).orElse(context);
   }
 
-  /**
-   * Sets up the base system WPILib so that it does not rely on hardware.
-   */
-  public static void setupMockBase() {
+  @Override
+  public void beforeAll(ExtensionContext context) throws Exception {
+    getRoot(context).getStore(Namespace.GLOBAL).getOrComputeIfAbsent("HAL Initalized", key -> {
+      initializeHardware();
+      return true;
+    }, Boolean.class);
+  }
+
+  private void initializeHardware() {
     HAL.initialize(500, 0);
     try {
       // Check to see if this has been setup

wpilibj/src/test/java/edu/wpi/first/wpilibj/PIDToleranceTest.java

@@ -8,7 +8,6 @@
 package edu.wpi.first.wpilibj;
 
 import org.junit.jupiter.api.AfterEach;
-import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
@@ -21,11 +20,6 @@ class PIDToleranceTest {
   private static final double m_tolerance = 10.0;
   private static final double m_range = 200;
 
-  @BeforeAll
-  static void setupClass() {
-    UnitTestUtility.setupMockBase();
-  }
-
   private class FakeInput implements PIDSource {
     public double m_val;
 

wpilibj/src/test/java/edu/wpi/first/wpilibj/UtilityClassTest.java

@@ -13,7 +13,6 @@ import java.lang.reflect.Modifier;
 import java.util.Arrays;
 import java.util.stream.Stream;
 
-import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.DynamicTest;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.TestFactory;
@@ -26,11 +25,6 @@ import static org.junit.jupiter.api.DynamicTest.dynamicTest;
 
 @SuppressWarnings("PMD.AbstractClassWithoutAbstractMethod")
 public abstract class UtilityClassTest {
-  @BeforeAll
-  static void setup() {
-    UnitTestUtility.setupMockBase();
-  }
-
   private final Class m_clazz;
 
   protected UtilityClassTest(Class clazz) {

wpilibj/src/test/java/edu/wpi/first/wpilibj/command/AbstractCommandTest.java

@@ -9,8 +9,6 @@ package edu.wpi.first.wpilibj.command;
 
 import org.junit.jupiter.api.BeforeEach;
 
-import edu.wpi.first.wpilibj.UnitTestUtility;
-
 import static org.junit.jupiter.api.Assertions.assertAll;
 import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -21,7 +19,6 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 public abstract class AbstractCommandTest {
   @BeforeEach
   void commandSetup() {
-    UnitTestUtility.setupMockBase();
     Scheduler.getInstance().removeAll();
     Scheduler.getInstance().enable();
   }

wpilibj/src/test/resources/META-INF/services/org.junit.jupiter.api.extension.Extension

@@ -0,0 +1 @@
+edu.wpi.first.wpilibj.MockHardwareExtension