Add null check for channel and calloptions when creating stub. Fixes #1438

stub/src/main/java/io/grpc/stub/AbstractStub.java

@@ -31,6 +31,8 @@
 
 package io.grpc.stub;
 
+import static com.google.common.base.Preconditions.checkNotNull;
+
 import io.grpc.CallOptions;
 import io.grpc.Channel;
 import io.grpc.ClientInterceptor;
@@ -69,8 +71,8 @@ public abstract class AbstractStub<S extends AbstractStub<S>> {
    * @param callOptions the runtime call options to be applied to every call on this stub
    */
   protected AbstractStub(Channel channel, CallOptions callOptions) {
-    this.channel = channel;
-    this.callOptions = callOptions;
+    this.channel = checkNotNull(channel);
+    this.callOptions = checkNotNull(callOptions);
   }
 
   /**

stub/src/test/java/io/grpc/stub/AbstractStubTest.java

@@ -0,0 +1,74 @@
+/*
+ * Copyright 2016, Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *    * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *    * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *
+ *    * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package io.grpc.stub;
+
+import io.grpc.CallOptions;
+import io.grpc.Channel;
+import org.junit.Test;
+import org.mockito.Mock;
+
+public class AbstractStubTest {
+
+  @Mock
+  Channel channel;
+
+  @Test(expected = NullPointerException.class)
+  public void channelMustNotBeNull() {
+    new NoopStub(null);
+  }
+
+  @Test(expected = NullPointerException.class)
+  public void callOptionsMustNotBeNull() {
+    new NoopStub(channel, null);
+  }
+
+  @Test(expected = NullPointerException.class)
+  public void callOptionsAndChannelMustNotBeNull() {
+    new NoopStub(null, null);
+  }
+
+  class NoopStub extends AbstractStub<NoopStub> {
+
+    NoopStub(Channel channel) {
+      super(channel);
+    }
+
+    NoopStub(Channel channel, CallOptions options) {
+      super(channel, options);
+    }
+
+    @Override
+    protected NoopStub build(Channel channel, CallOptions callOptions) {
+      return new NoopStub(channel, callOptions);
+    }
+  }
+}