[build] Enable spotbugs (#3601)

Benign spotbugs warnings were suppressed, and all others were fixed. Bug
descriptions are documented here:
https://spotbugs.readthedocs.io/en/stable/bugDescriptions.html

Co-authored-by: Austin Shalit <austinshalit@gmail.com>

wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/AnalogCrossConnectFixture.java

@@ -34,10 +34,9 @@ public abstract class AnalogCrossConnectFixture implements ITestFixture {
    * @see edu.wpi.first.wpilibj.fixtures.ITestFixture#setup()
    */
   @Override
-  public boolean setup() {
+  public void setup() {
     initialize();
     m_output.setVoltage(0);
-    return true;
   }
 
   /*
@@ -46,9 +45,8 @@ public abstract class AnalogCrossConnectFixture implements ITestFixture {
    * @see edu.wpi.first.wpilibj.fixtures.ITestFixture#reset()
    */
   @Override
-  public boolean reset() {
+  public void reset() {
     initialize();
-    return true;
   }
 
   /*
@@ -57,10 +55,9 @@ public abstract class AnalogCrossConnectFixture implements ITestFixture {
    * @see edu.wpi.first.wpilibj.fixtures.ITestFixture#teardown()
    */
   @Override
-  public boolean teardown() {
+  public void teardown() {
     m_input.close();
     m_output.close();
-    return true;
   }
 
   /** Analog Output. */

wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/DIOCrossConnectFixture.java

@@ -55,24 +55,20 @@ public class DIOCrossConnectFixture implements ITestFixture {
   }
 
   @Override
-  public boolean setup() {
-    return true;
-  }
+  public void setup() {}
 
   @Override
-  public boolean reset() {
+  public void reset() {
     m_output.set(false);
-    return true;
   }
 
   @Override
-  public boolean teardown() {
+  public void teardown() {
     logger.log(Level.FINE, "Beginning teardown");
     if (m_allocated) {
       m_input.close();
       m_output.close();
       m_allocated = false;
     }
-    return true;
   }
 }

wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/FakeCounterFixture.java

@@ -67,9 +67,7 @@ public class FakeCounterFixture implements ITestFixture {
    * @see edu.wpi.first.wpilibj.fixtures.ITestFixture#setup()
    */
   @Override
-  public boolean setup() {
-    return true;
-  }
+  public void setup() {}
 
   /*
    * (non-Javadoc)
@@ -77,9 +75,8 @@ public class FakeCounterFixture implements ITestFixture {
    * @see edu.wpi.first.wpilibj.fixtures.ITestFixture#reset()
    */
   @Override
-  public boolean reset() {
+  public void reset() {
     m_counter.reset();
-    return true;
   }
 
   /*
@@ -88,7 +85,7 @@ public class FakeCounterFixture implements ITestFixture {
    * @see edu.wpi.first.wpilibj.fixtures.ITestFixture#teardown()
    */
   @Override
-  public boolean teardown() {
+  public void teardown() {
     logger.log(Level.FINE, "Beginning teardown");
     m_counter.close();
     m_source.close();
@@ -96,6 +93,5 @@ public class FakeCounterFixture implements ITestFixture {
       m_dio.teardown();
       m_allocated = false;
     }
-    return true;
   }
 }

wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/FakeEncoderFixture.java

@@ -68,9 +68,7 @@ public class FakeEncoderFixture implements ITestFixture {
    * @see edu.wpi.first.wpilibj.fixtures.ITestFixture#setup()
    */
   @Override
-  public boolean setup() {
-    return true;
-  }
+  public void setup() {}
 
   /*
    * (non-Javadoc)
@@ -78,11 +76,10 @@ public class FakeEncoderFixture implements ITestFixture {
    * @see edu.wpi.first.wpilibj.fixtures.ITestFixture#reset()
    */
   @Override
-  public boolean reset() {
+  public void reset() {
     m_dio1.reset();
     m_dio2.reset();
     m_encoder.reset();
-    return true;
   }
 
   /*
@@ -91,7 +88,7 @@ public class FakeEncoderFixture implements ITestFixture {
    * @see edu.wpi.first.wpilibj.fixtures.ITestFixture#teardown()
    */
   @Override
-  public boolean teardown() {
+  public void teardown() {
     logger.fine("Beginning teardown");
     m_source.close();
     logger.finer("Source freed " + m_sourcePort[0] + ",  " + m_sourcePort[1]);
@@ -101,6 +98,5 @@ public class FakeEncoderFixture implements ITestFixture {
       m_dio1.teardown();
       m_dio2.teardown();
     }
-    return true;
   }
 }

wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/ITestFixture.java

@@ -18,10 +18,8 @@ public interface ITestFixture {
   /**
    * Performs any required setup for this fixture, ensuring that all fixture elements are ready for
    * testing.
-   *
-   * @return True if the fixture is ready for testing
    */
-  boolean setup();
+  void setup();
 
   /**
    * Resets the fixture back to test start state. This should be called by the test class in the
@@ -29,16 +27,12 @@ public interface ITestFixture {
    * ITestFixture#setup()} as that is called once, before the class is constructed, so it may need
    * to start sensors. This method should not have to start anything, just reset sensors and ensure
    * that motors are stopped.
-   *
-   * @return True if the fixture is ready for testing
    */
-  boolean reset();
+  void reset();
 
   /**
    * Performs any required teardown after use of the fixture, ensuring that future tests will not
    * run into conflicts.
-   *
-   * @return True if the teardown succeeded
    */
-  boolean teardown();
+  void teardown();
 }

wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/MotorEncoderFixture.java

@@ -82,9 +82,8 @@ public abstract class MotorEncoderFixture<T extends MotorController> implements
   }
 
   @Override
-  public boolean setup() {
+  public void setup() {
     initialize();
-    return true;
   }
 
   /**
@@ -136,7 +135,7 @@ public abstract class MotorEncoderFixture<T extends MotorController> implements
   }
 
   @Override
-  public boolean reset() {
+  public void reset() {
     initialize();
     m_motor.setInverted(false);
     m_motor.set(0);
@@ -145,15 +144,6 @@ public abstract class MotorEncoderFixture<T extends MotorController> implements
     for (Counter c : m_counters) {
       c.reset();
     }
-
-    boolean wasReset = true;
-    wasReset = wasReset && m_motor.get() == 0;
-    wasReset = wasReset && m_encoder.get() == 0;
-    for (Counter c : m_counters) {
-      wasReset = wasReset && c.get() == 0;
-    }
-
-    return wasReset;
   }
 
   /**
@@ -163,62 +153,37 @@ public abstract class MotorEncoderFixture<T extends MotorController> implements
    */
   @Override
   @SuppressWarnings("Regexp")
-  public boolean teardown() {
-    String type;
-    if (m_motor != null) {
-      type = getType();
-    } else {
-      type = "null";
-    }
+  public void teardown() {
     if (!m_tornDown) {
-      boolean wasNull = false;
-      if (m_motor instanceof PWM && m_motor != null) {
-        ((PWM) m_motor).close();
+      if (m_motor != null) {
+        if (m_motor instanceof PWM) {
+          ((PWM) m_motor).close();
+        }
         m_motor = null;
-      } else if (m_motor == null) {
-        wasNull = true;
       }
       if (m_encoder != null) {
         m_encoder.close();
         m_encoder = null;
-      } else {
-        wasNull = true;
       }
       if (m_counters[0] != null) {
         m_counters[0].close();
         m_counters[0] = null;
-      } else {
-        wasNull = true;
       }
       if (m_counters[1] != null) {
         m_counters[1].close();
         m_counters[1] = null;
-      } else {
-        wasNull = true;
       }
       if (m_alphaSource != null) {
         m_alphaSource.close();
         m_alphaSource = null;
-      } else {
-        wasNull = true;
       }
       if (m_betaSource != null) {
         m_betaSource.close();
         m_betaSource = null;
-      } else {
-        wasNull = true;
       }
 
       m_tornDown = true;
-
-      if (wasNull) {
-        throw new NullPointerException("MotorEncoderFixture had null params at teardown");
-      }
-    } else {
-      throw new RuntimeException(type + " Motor Encoder torn down multiple times");
     }
-
-    return true;
   }
 
   @Override

wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/RelayCrossConnectFixture.java

@@ -54,9 +54,8 @@ public abstract class RelayCrossConnectFixture implements ITestFixture {
    * @see edu.wpi.first.wpilibj.fixtures.ITestFixture#setup()
    */
   @Override
-  public boolean setup() {
+  public void setup() {
     initialize();
-    return true;
   }
 
   /*
@@ -65,9 +64,8 @@ public abstract class RelayCrossConnectFixture implements ITestFixture {
    * @see edu.wpi.first.wpilibj.fixtures.ITestFixture#reset()
    */
   @Override
-  public boolean reset() {
+  public void reset() {
     initialize();
-    return true;
   }
 
   /*
@@ -76,7 +74,7 @@ public abstract class RelayCrossConnectFixture implements ITestFixture {
    * @see edu.wpi.first.wpilibj.fixtures.ITestFixture#teardown()
    */
   @Override
-  public boolean teardown() {
+  public void teardown() {
     if (!m_freed) {
       m_relay.close();
       m_inputOne.close();
@@ -88,6 +86,5 @@ public abstract class RelayCrossConnectFixture implements ITestFixture {
               + RelayCrossConnectFixture.class.getSimpleName()
               + " multiple times");
     }
-    return true;
   }
 }

wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/SampleFixture.java

@@ -10,35 +10,32 @@ package edu.wpi.first.wpilibj.fixtures;
  */
 public class SampleFixture implements ITestFixture {
   @Override
-  public boolean setup() {
+  public void setup() {
     /*
      * If this fixture actually accessed the hardware, here is where it would
      * set up the starting state of the test bench. For example, reseting
      * encoders, ensuring motors are stopped, reseting any serial communication
      * if necessary, etc.
      */
-    return true;
   }
 
   @Override
-  public boolean reset() {
+  public void reset() {
     /*
      * This is where the fixture would reset any sensors or motors used by the
      * fixture to test default state. This method should not worry about whether
      * or not the sensors have been allocated correctly, that is the job of the
      * setup function.
      */
-    return false;
   }
 
   @Override
-  public boolean teardown() {
+  public void teardown() {
     /*
      * This is where the fixture would deallocate and reset back to normal
      * conditions any necessary hardware. This includes ensuring motors are
      * stopped, stoppable sensors are actually stopped, ensuring serial
      * communications are ready for the next test, etc.
      */
-    return true;
   }
 }

wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/TiltPanCameraFixture.java

@@ -35,8 +35,7 @@ public abstract class TiltPanCameraFixture implements ITestFixture {
   public TiltPanCameraFixture() {}
 
   @Override
-  public boolean setup() {
-    boolean wasSetup = false;
+  public void setup() {
     if (!m_initialized) {
       m_initialized = true;
       m_tilt = giveTilt();
@@ -48,17 +47,14 @@ public abstract class TiltPanCameraFixture implements ITestFixture {
       logger.fine("Initializing the gyro");
       m_gyro = giveGyro();
       m_gyro.reset();
-      wasSetup = true;
     }
-    return wasSetup;
   }
 
   @Override
-  public boolean reset() {
+  public void reset() {
     if (m_gyro != null) {
       m_gyro.reset();
     }
-    return true;
   }
 
   public Servo getTilt() {
@@ -89,7 +85,7 @@ public abstract class TiltPanCameraFixture implements ITestFixture {
   }
 
   @Override
-  public boolean teardown() {
+  public void teardown() {
     m_tilt.close();
     m_tilt = null;
     m_pan.close();
@@ -102,6 +98,5 @@ public abstract class TiltPanCameraFixture implements ITestFixture {
       m_gyroParam.close();
       m_gyroParam = null;
     }
-    return true;
   }
 }