Merge pull request #1 from davidmoten/master

Update with DaveMoten last commits

src/main/java/com/github/davidmoten/rtree/Backpressure.java

@@ -11,6 +11,10 @@
  */
 final class Backpressure {
 
+    private Backpressure() {
+        // prevent instantiation
+    }
+
     static <T> ImmutableStack<NodePosition<T>> search(
             final Func1<? super Geometry, Boolean> condition,
             final Subscriber<? super Entry<T>> subscriber, ImmutableStack<NodePosition<T>> stack,

src/main/java/com/github/davidmoten/rtree/Comparators.java

@@ -15,6 +15,10 @@
  *
  */
 public final class Comparators {
+
+    private Comparators() {
+        //prevent instantiation
+    }
 
     public static final Comparator<ListPair<?>> overlapListPairComparator = toComparator(Functions.overlapListPair);
 

src/main/java/com/github/davidmoten/rtree/Functions.java

@@ -14,6 +14,10 @@
  */
 public final class Functions {
 
+    private Functions() {
+        // prevent instantiation
+    }
+
     public static final Func1<ListPair<? extends HasGeometry>, Double> overlapListPair = new Func1<ListPair<? extends HasGeometry>, Double>() {
 
         @Override

src/main/java/com/github/davidmoten/rtree/Util.java

@@ -18,10 +18,6 @@ private Util() {
         // prevent instantiation
     }
 
-    static void instantiateForTestCoveragePurposesOnly() {
-        new Util();
-    }
-
     /**
      * Returns the minimum bounding rectangle of a number of items. Benchmarks
      * below indicate that when the number of items is >1 this method is more

src/test/java/com/github/davidmoten/rtree/BackpressureTest.java

@@ -18,9 +18,15 @@
 
 import com.github.davidmoten.rtree.geometry.Geometry;
 import com.github.davidmoten.util.ImmutableStack;
+import com.github.davidmoten.util.TestingUtil;
 
 public class BackpressureTest {
 
+    @Test
+    public void testConstructorIsPrivate() {
+        TestingUtil.callConstructorAndCheckIsPrivate(Backpressure.class);
+    }
+
     @SuppressWarnings("unchecked")
     @Test
     public void testBackpressureSearch() {

src/test/java/com/github/davidmoten/rtree/ComparatorsTest.java

@@ -0,0 +1,14 @@
+package com.github.davidmoten.rtree;
+
+import org.junit.Test;
+
+import com.github.davidmoten.util.TestingUtil;
+
+public class ComparatorsTest {
+
+    @Test
+    public void  testConstructorIsPrivate() {
+        TestingUtil.callConstructorAndCheckIsPrivate(Comparators.class);
+    }
+
+}

src/test/java/com/github/davidmoten/rtree/FunctionsTest.java

@@ -0,0 +1,13 @@
+package com.github.davidmoten.rtree;
+
+import org.junit.Test;
+
+import com.github.davidmoten.util.TestingUtil;
+
+public class FunctionsTest {
+
+    @Test
+    public void testConstructorIsPrivate() {
+        TestingUtil.callConstructorAndCheckIsPrivate(Functions.class);
+    }
+}

src/test/java/com/github/davidmoten/rtree/UtilTest.java

@@ -2,11 +2,13 @@
 
 import org.junit.Test;
 
+import com.github.davidmoten.util.TestingUtil;
+
 public class UtilTest {
 
     @Test
     public void coverPrivateConstructor() {
-        Util.instantiateForTestCoveragePurposesOnly();
+        TestingUtil.callConstructorAndCheckIsPrivate(Util.class);
     }
 
 }

src/test/java/com/github/davidmoten/util/TestingUtil.java

@@ -0,0 +1,47 @@
+package com.github.davidmoten.util;
+
+import static org.junit.Assert.assertTrue;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Modifier;
+
+/**
+ * Utility methods for unit tests.
+ * 
+ * @author dave
+ * 
+ */
+public class TestingUtil {
+
+    /**
+     * Checks that a class has a no-argument private constructor and calls that
+     * constructor to instantiate the class.
+     * 
+     * @param cls
+     */
+    public static <T> void callConstructorAndCheckIsPrivate(Class<T> cls) {
+        Constructor<T> constructor;
+        try {
+            constructor = cls.getDeclaredConstructor();
+        } catch (NoSuchMethodException e1) {
+            throw new RuntimeException(e1);
+        } catch (SecurityException e1) {
+            throw new RuntimeException(e1);
+        }
+        assertTrue(Modifier.isPrivate(constructor.getModifiers()));
+        constructor.setAccessible(true);
+        try {
+            constructor.newInstance();
+        } catch (InstantiationException e) {
+            throw new RuntimeException(e);
+        } catch (IllegalAccessException e) {
+            throw new RuntimeException(e);
+        } catch (IllegalArgumentException e) {
+            throw new RuntimeException(e);
+        } catch (InvocationTargetException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+}