1.x: Test all private Constructors (ReactiveX#4125)

* 1.x: Test all private Constructors

* Revert exception type and message back

Author: vanniktech

build.gradle

@@ -27,6 +27,7 @@ dependencies {
     testCompile 'junit:junit:4.12'
     testCompile 'org.mockito:mockito-core:1.10.19'
     testCompile 'com.google.guava:guava:19.0'
+    testCompile 'com.pushtorefresh.java-private-constructor-checker:checker:1.2.0'
 
     perfCompile 'org.openjdk.jmh:jmh-core:1.11.3'
     perfCompile 'org.openjdk.jmh:jmh-generator-annprocess:1.11.3'

src/main/java/rx/internal/util/unsafe/Pow2.java

@@ -41,4 +41,4 @@ public static int roundToPowerOfTwo(final int value) {
     public static boolean isPowerOfTwo(final int value) {
         return (value & (value - 1)) == 0;
     }
-}
+}

src/main/java/rx/internal/util/unsafe/UnsafeAccess.java

@@ -117,4 +117,4 @@ public static long addressOf(Class<?> clazz, String fieldName) {
             throw ie;
         }
     }
-}
+}

src/test/java/rx/EventStreamTest.java

@@ -0,0 +1,27 @@
+/**
+ * Copyright 2016 Netflix, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package rx;
+
+import com.pushtorefresh.private_constructor_checker.PrivateConstructorChecker;
+
+import org.junit.Test;
+
+public class EventStreamTest {
+    @Test
+    public void constructorShouldBePrivate() {
+        PrivateConstructorChecker.forClass(EventStream.class).expectedTypeOfException(IllegalStateException.class).expectedExceptionMessage("No instances!").check();
+    }
+}

src/test/java/rx/exceptions/ExceptionsTest.java

@@ -18,6 +18,8 @@
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
+import com.pushtorefresh.private_constructor_checker.PrivateConstructorChecker;
+
 import java.util.concurrent.atomic.AtomicInteger;
 
 import org.junit.Test;
@@ -33,6 +35,10 @@
 import rx.subjects.PublishSubject;
 
 public class ExceptionsTest {
+    @Test
+    public void constructorShouldBePrivate() {
+        PrivateConstructorChecker.forClass(Exceptions.class).expectedTypeOfException(IllegalStateException.class).expectedExceptionMessage("No instances!").check();
+    }
 
     @Test(expected = OnErrorNotImplementedException.class)
     public void testOnErrorNotImplementedIsThrown() {

src/test/java/rx/functions/ActionsTest.java

@@ -15,13 +15,15 @@
  */
 package rx.functions;
 
-import static org.junit.Assert.*;
+import com.pushtorefresh.private_constructor_checker.PrivateConstructorChecker;
+
+import org.junit.Test;
 
-import java.lang.reflect.*;
 import java.util.Arrays;
 import java.util.concurrent.atomic.AtomicLong;
 
-import org.junit.Test;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
 
 public class ActionsTest {
 
@@ -271,20 +273,7 @@ public void call(Object... args) {
     }
 
     @Test
-    public void testNotInstantiable() {
-        try {
-            Constructor<?> c = Actions.class.getDeclaredConstructor();
-            c.setAccessible(true);
-            Object instance = c.newInstance();
-            fail("Could instantiate Actions! " + instance);
-        } catch (NoSuchMethodException ex) {
-            ex.printStackTrace();
-        } catch (InvocationTargetException ex) {
-            ex.printStackTrace();
-        } catch (InstantiationException ex) {
-            ex.printStackTrace();
-        } catch (IllegalAccessException ex) {
-            ex.printStackTrace();
-        }
+    public void constructorShouldBePrivate() {
+        PrivateConstructorChecker.forClass(Actions.class).expectedTypeOfException(IllegalStateException.class).expectedExceptionMessage("No instances!").check();
     }
 }

src/test/java/rx/functions/FunctionsTest.java

@@ -15,31 +15,19 @@
  */
 package rx.functions;
 
-import static org.junit.Assert.*;
+import com.pushtorefresh.private_constructor_checker.PrivateConstructorChecker;
+
+import org.junit.Test;
 
-import java.lang.reflect.*;
 import java.util.Arrays;
 import java.util.concurrent.atomic.AtomicLong;
 
-import org.junit.Test;
+import static org.junit.Assert.assertEquals;
 
 public class FunctionsTest {
     @Test
-    public void testNotInstantiable() {
-        try {
-            Constructor<?> c = Functions.class.getDeclaredConstructor();
-            c.setAccessible(true);
-            Object instance = c.newInstance();
-            fail("Could instantiate Actions! " + instance);
-        } catch (NoSuchMethodException ex) {
-            ex.printStackTrace();
-        } catch (InvocationTargetException ex) {
-            ex.printStackTrace();
-        } catch (InstantiationException ex) {
-            ex.printStackTrace();
-        } catch (IllegalAccessException ex) {
-            ex.printStackTrace();
-        }
+    public void constructorShouldBePrivate() {
+        PrivateConstructorChecker.forClass(Functions.class).expectedTypeOfException(IllegalStateException.class).expectedExceptionMessage("No instances!").check();
     }
 
     @Test(expected = RuntimeException.class)

src/test/java/rx/internal/operators/BackpressureUtilsTest.java

@@ -15,10 +15,17 @@
  */
 package rx.internal.operators;
 
+import com.pushtorefresh.private_constructor_checker.PrivateConstructorChecker;
+
 import org.junit.Test;
 import static org.junit.Assert.*;
 
 public class BackpressureUtilsTest {
+    @Test
+    public void constructorShouldBePrivate() {
+        PrivateConstructorChecker.forClass(BackpressureUtils.class).expectedTypeOfException(IllegalStateException.class).expectedExceptionMessage("No instances!").check();
+    }
+
     @Test
     public void testAddCap() {
         assertEquals(2L, BackpressureUtils.addCap(1, 1));

src/test/java/rx/internal/operators/BlockingOperatorLatestTest.java

@@ -15,6 +15,8 @@
  */
 package rx.internal.operators;
 
+import com.pushtorefresh.private_constructor_checker.PrivateConstructorChecker;
+
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 import java.util.concurrent.TimeUnit;
@@ -29,6 +31,11 @@
 import rx.subjects.PublishSubject;
 
 public class BlockingOperatorLatestTest {
+    @Test
+    public void constructorShouldBePrivate() {
+        PrivateConstructorChecker.forClass(BlockingOperatorLatest.class).expectedTypeOfException(IllegalStateException.class).expectedExceptionMessage("No instances!").check();
+    }
+
     @Test(timeout = 1000)
     public void testSimple() {
         TestScheduler scheduler = new TestScheduler();

src/test/java/rx/internal/operators/BlockingOperatorMostRecentTest.java

@@ -20,6 +20,8 @@
 import static org.junit.Assert.assertTrue;
 import static rx.internal.operators.BlockingOperatorMostRecent.mostRecent;
 
+import com.pushtorefresh.private_constructor_checker.PrivateConstructorChecker;
+
 import java.util.Iterator;
 import java.util.concurrent.TimeUnit;
 
@@ -34,6 +36,11 @@
 import rx.subjects.Subject;
 
 public class BlockingOperatorMostRecentTest {
+    @Test
+    public void constructorShouldBePrivate() {
+        PrivateConstructorChecker.forClass(BlockingOperatorMostRecent.class).expectedTypeOfException(IllegalStateException.class).expectedExceptionMessage("No instances!").check();
+    }
+
     @Test
     public void testMostRecentNull() {
         assertEquals(null, Observable.<Void>never().toBlocking().mostRecent(null).iterator().next());