Improve unit tests and add forLoop to CommandBuilder

Author: James Hagborg

src/main/java/org/usfirst/frc/team69/util/CommandBuilder.java

@@ -193,6 +193,29 @@ public CommandBuilder whileLoop(BooleanSupplier condition, Command body) {
         return this;
     }
 
+    // This needs to be a class, so we can pass-by-reference to the loop command
+    private static class Counter {
+        public int value = 0;
+    }
+    
+    /**
+     * Run a command a given number of times.  This is effectively a for loop,
+     * although the command cannot make use of the value of the counter.
+     * 
+     * This uses {@link #whileLoop(BooleanSupplier, Command)} under the hood,
+     * so the semantics are the same as that.
+     * 
+     * @param count The number of times to run the command.
+     * @param body The body of the command to execute.
+     * @return This CommandBuilder object
+     */
+    public CommandBuilder forLoop(int count, Command body) {
+        Counter counter = new Counter();
+        m_cmdGroup.addSequential(QuickCommand.oneShot(null, () -> counter.value = 0));
+        m_cmdGroup.addSequential(new WhileCommand(() -> counter.value++ < count, body));
+        return this;
+    }
+    
     /**
      * End any command currently running on the subsystem.  This is accomplished
      * by running a command which ends instantly, which requires the given

src/test/java/org/usfirst/frc/team69/util/oi/test/ForCommandTest.java

@@ -0,0 +1,50 @@
+package org.usfirst.frc.team69.util.oi.test;
+
+import static org.junit.Assert.*;
+
+import java.util.concurrent.TimeUnit;
+
+import org.junit.BeforeClass;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.Timeout;
+import org.usfirst.frc.team69.util.CommandBuilder;
+
+import edu.wpi.first.wpilibj.MockCommand;
+import edu.wpi.first.wpilibj.UnitTestUtility;
+import edu.wpi.first.wpilibj.command.Command;
+import edu.wpi.first.wpilibj.command.Scheduler;
+
+public class ForCommandTest {
+
+    // We're looping conditional on code under test, want to make sure that doesn't break
+    @Rule
+    public Timeout globalTimeout = new Timeout(100, TimeUnit.MILLISECONDS);
+    
+    @BeforeClass
+    public static void setUpBeforeClass() throws Exception {
+        UnitTestUtility.setupMockBase();
+    }
+
+    @Test
+    public void testForLoop() {
+        MockCommand mockCommand = new MockCommand();
+        mockCommand.setHasFinished(true);
+        Command loopCommand = new CommandBuilder()
+                .forLoop(10, mockCommand)
+                .build();
+        loopCommand.start();
+        Scheduler.getInstance().run();
+        
+        while (loopCommand.isRunning()) {
+            Scheduler.getInstance().run();
+        }
+        
+        assertEquals(10, mockCommand.getExecuteCount());
+        assertEquals(10, mockCommand.getIsFinishedCount());
+        assertEquals(10, mockCommand.getInitializeCount());
+        assertEquals(10, mockCommand.getEndCount());
+        assertEquals(0, mockCommand.getInterruptedCount());
+    }
+
+}

src/test/java/org/usfirst/frc/team69/util/oi/test/MockCondition.java

@@ -5,6 +5,7 @@
 public class MockCondition implements BooleanSupplier {
 
     private boolean m_cond;
+    private int timesChecked = 0;
 
     public MockCondition(boolean startState) {
         m_cond = startState;
@@ -16,7 +17,11 @@ public void set(boolean state) {
 
     @Override
     public boolean getAsBoolean() {
+        timesChecked++;
         return m_cond;
     }
 
+    public int getTimesChecked() {
+        return timesChecked;
+    }
 }

src/test/java/org/usfirst/frc/team69/util/oi/test/WhileCommandTest.java

@@ -77,6 +77,8 @@ public void testWhileCommandRuns() {
         assertEquals(50, body.getIsFinishedCount());
         assertEquals(10, body.getEndCount());
         assertEquals(0, body.getInterruptedCount());
+        // The loop ran 10 times, and started an 11th
+        assertEquals(11, condition.getTimesChecked());
     }
 
     @Test
@@ -109,6 +111,7 @@ public void testDoesNotRunIfFalse() {
         assertEquals(0, body.getIsFinishedCount());
         assertEquals(0, body.getEndCount());
         assertEquals(0, body.getInterruptedCount());
+        assertEquals(1, condition.getTimesChecked());
     }
 
     @Test
@@ -130,6 +133,8 @@ public void testEndsWhenFalse() {
         assertEquals(1, body.getIsFinishedCount());
         assertEquals(1, body.getEndCount());
         assertEquals(0, body.getInterruptedCount());
+        // checked once at start, another at end
+        assertEquals(2, condition.getTimesChecked());
     }
 
     @Test
@@ -149,6 +154,7 @@ public void testCancelWhileCommand() {
         assertEquals(1, body.getIsFinishedCount());
         assertEquals(0, body.getEndCount());
         assertEquals(1, body.getInterruptedCount());
+        assertEquals(1, condition.getTimesChecked());
     }
 
     @Test
@@ -171,6 +177,7 @@ public void testCancelBodyCommand() {
         assertEquals(2, body.getInitializeCount());
         assertEquals(0, body.getEndCount());
         assertEquals(1, body.getInterruptedCount());
+        assertEquals(2, condition.getTimesChecked());
     }
 
 }