core: stop "testing" from depending on "core"'s test. (#2652)

Because "core"'s test source already depends on "testing", e.g.,
`core/src/test/java/io/grpc/internal/ServerCallImplTest.java` uses
`testing/src/main/java/io/grpc/internal/testing/StatsTestUtils.java`,
which forms a circular dependency.

This change moves the StatsContext setter accessors from "core"'s test
source to "testing".

Resolves #2651

core/src/test/java/io/grpc/internal/TestUtils.java

@@ -36,8 +36,6 @@ import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
-import com.google.instrumentation.stats.StatsContextFactory;
-
 import io.grpc.CallOptions;
 import io.grpc.Metadata;
 import io.grpc.MethodDescriptor;
@@ -53,7 +51,7 @@ import javax.annotation.Nullable;
 /**
  * Common utility methods for tests.
  */
-public final class TestUtils {
+final class TestUtils {
 
   static class MockClientTransportInfo {
     /**
@@ -113,22 +111,6 @@ public final class TestUtils {
     return captor;
   }
 
-  /**
-   * Sets a custom {@link StatsContextFactory} for tests.
-   */
-  public static void setStatsContextFactory(
-      AbstractManagedChannelImplBuilder<?> builder, StatsContextFactory factory) {
-    builder.statsContextFactory(factory);
-  }
-
-  /**
-   * Sets a custom {@link StatsContextFactory} for tests.
-   */
-  public static void setStatsContextFactory(
-      AbstractServerImplBuilder<?> builder, StatsContextFactory factory) {
-    builder.statsContextFactory(factory);
-  }
-
   private TestUtils() {
   }
 }

interop-testing/build.gradle

@@ -16,10 +16,6 @@ dependencies {
             libraries.mockito,
             libraries.netty_tcnative,
             libraries.oauth_client
-
-    // Tests depend on base class defined by core module.
-    compile project(':grpc-core').sourceSets.test.output
-    testCompile project(':grpc-core').sourceSets.test.output
 }
 
 test {

interop-testing/src/main/java/io/grpc/testing/integration/AbstractInteropTest.java

@@ -152,7 +152,7 @@ public abstract class AbstractInteropTest {
     builder.addService(ServerInterceptors.intercept(
         new TestServiceImpl(testServiceExecutor),
         allInterceptors));
-    io.grpc.internal.TestUtils.setStatsContextFactory(builder, serverStatsFactory);
+    io.grpc.internal.TestingAccessor.setStatsContextFactory(builder, serverStatsFactory);
     try {
       server = builder.build().start();
     } catch (IOException ex) {

interop-testing/src/test/java/io/grpc/testing/integration/AutoWindowSizingOnTest.java

@@ -64,7 +64,7 @@ public class AutoWindowSizingOnTest extends AbstractInteropTest {
     NettyChannelBuilder builder = NettyChannelBuilder.forAddress("localhost", getPort())
         .negotiationType(NegotiationType.PLAINTEXT)
         .maxInboundMessageSize(AbstractInteropTest.MAX_MESSAGE_SIZE);
-    io.grpc.internal.TestUtils.setStatsContextFactory(builder, getClientStatsFactory());
+    io.grpc.internal.TestingAccessor.setStatsContextFactory(builder, getClientStatsFactory());
     return builder.build();
   }
 }

interop-testing/src/test/java/io/grpc/testing/integration/Http2NettyLocalChannelTest.java

@@ -75,7 +75,7 @@ public class Http2NettyLocalChannelTest extends AbstractInteropTest {
         .channelType(LocalChannel.class)
         .flowControlWindow(65 * 1024)
         .maxInboundMessageSize(AbstractInteropTest.MAX_MESSAGE_SIZE);
-    io.grpc.internal.TestUtils.setStatsContextFactory(builder, getClientStatsFactory());
+    io.grpc.internal.TestingAccessor.setStatsContextFactory(builder, getClientStatsFactory());
     return builder.build();
   }
 }

interop-testing/src/test/java/io/grpc/testing/integration/Http2NettyTest.java

@@ -92,7 +92,7 @@ public class Http2NettyTest extends AbstractInteropTest {
               .ciphers(TestUtils.preferredTestCiphers(), SupportedCipherSuiteFilter.INSTANCE)
               .sslProvider(SslProvider.OPENSSL)
               .build());
-      io.grpc.internal.TestUtils.setStatsContextFactory(builder, getClientStatsFactory());
+      io.grpc.internal.TestingAccessor.setStatsContextFactory(builder, getClientStatsFactory());
       return builder.build();
     } catch (Exception ex) {
       throw new RuntimeException(ex);

interop-testing/src/test/java/io/grpc/testing/integration/Http2OkHttpTest.java

@@ -110,7 +110,7 @@ public class Http2OkHttpTest extends AbstractInteropTest {
             .build())
         .overrideAuthority(GrpcUtil.authorityFromHostAndPort(
             TestUtils.TEST_SERVER_HOST, getPort()));
-    io.grpc.internal.TestUtils.setStatsContextFactory(builder, getClientStatsFactory());
+    io.grpc.internal.TestingAccessor.setStatsContextFactory(builder, getClientStatsFactory());
     try {
       builder.sslSocketFactory(TestUtils.newSslSocketFactoryForCa(Platform.get().getProvider(),
               TestUtils.loadCert("ca.pem")));

interop-testing/src/test/java/io/grpc/testing/integration/TransportCompressionTest.java

@@ -190,7 +190,7 @@ public class TransportCompressionTest extends AbstractInteropTest {
           }
         })
         .usePlaintext(true);
-    io.grpc.internal.TestUtils.setStatsContextFactory(builder, getClientStatsFactory());
+    io.grpc.internal.TestingAccessor.setStatsContextFactory(builder, getClientStatsFactory());
     return builder.build();
   }
 

testing/src/main/java/io/grpc/internal/TestingAccessor.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright 2017, 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.internal;
+
+import com.google.instrumentation.stats.StatsContextFactory;
+
+/**
+ * Test helper that allows accessing package-private stuff.
+ */
+public final class TestingAccessor {
+  /**
+   * Sets a custom {@link StatsContextFactory} for tests.
+   */
+  public static void setStatsContextFactory(
+      AbstractManagedChannelImplBuilder<?> builder, StatsContextFactory factory) {
+    builder.statsContextFactory(factory);
+  }
+
+  /**
+   * Sets a custom {@link StatsContextFactory} for tests.
+   */
+  public static void setStatsContextFactory(
+      AbstractServerImplBuilder<?> builder, StatsContextFactory factory) {
+    builder.statsContextFactory(factory);
+  }
+
+  private TestingAccessor() {
+  }
+}