Enable the Guava Beta Checker

auth/src/main/java/io/grpc/auth/GoogleAuthLibraryCallCredentials.java

@@ -167,6 +167,7 @@ final class GoogleAuthLibraryCallCredentials implements CallCredentials {
     }
   }
 
+  @SuppressWarnings("BetaApi") // BaseEncoding is stable in Guava 20.0
   private static Metadata toHeaders(@Nullable Map<String, List<String>> metadata) {
     Metadata headers = new Metadata();
     if (metadata != null) {

build.gradle

@@ -9,7 +9,8 @@ buildscript {
   dependencies {
     classpath 'com.google.gradle:osdetector-gradle-plugin:1.4.0'
     classpath 'ru.vyarus:gradle-animalsniffer-plugin:1.4.0'
-    classpath 'net.ltgt.gradle:gradle-errorprone-plugin:0.0.11'
+    classpath 'net.ltgt.gradle:gradle-errorprone-plugin:0.0.13'
+    classpath 'net.ltgt.gradle:gradle-apt-plugin:0.13'
     classpath "me.champeau.gradle:jmh-gradle-plugin:0.4.4"
     classpath 'me.champeau.gradle:japicmp-gradle-plugin:0.2.5'
   }
@@ -29,11 +30,13 @@ subprojects {
     apply plugin: "ru.vyarus.animalsniffer"
     if (!rootProject.hasProperty('errorProne') || rootProject.errorProne.toBoolean()) {
       apply plugin: "net.ltgt.errorprone"
+      apply plugin: "net.ltgt.apt"
 
       dependencies {
         // The ErrorProne plugin defaults to the latest, which would break our
         // build if error prone releases a new version with a new check
         errorprone 'com.google.errorprone:error_prone_core:2.0.21'
+        apt 'com.google.guava:guava-beta-checker:1.0'
       }
     } else {
       // Remove per-project error-prone checker config

core/src/main/java/io/grpc/Metadata.java

@@ -455,6 +455,7 @@ public final class Metadata {
     }
   }
 
+  @SuppressWarnings("BetaApi") // BaseEncoding is stable in Guava 20.0
   @Override
   public String toString() {
     StringBuilder sb = new StringBuilder("Metadata(");

core/src/main/java/io/grpc/internal/DnsNameResolver.java

@@ -371,6 +371,7 @@ final class DnsNameResolver extends NameResolver {
 
     private static final Pattern whitespace = Pattern.compile("\\s+");
 
+    @SuppressWarnings("BetaApi") // Verify is stable in Guava 23.5
     @Override
     ResolutionResults resolve(String host) throws NamingException {
       List<String> serviceConfigTxtRecords = Collections.emptyList();

core/src/main/java/io/grpc/internal/TransportFrameUtil.java

@@ -44,6 +44,7 @@ public final class TransportFrameUtil {
    *
    * @return the interleaved keys and values.
    */
+  @SuppressWarnings("BetaApi") // BaseEncoding is stable in Guava 20.0
   public static byte[][] toHttp2Headers(Metadata headers) {
     byte[][] serializedHeaders = InternalMetadata.serialize(headers);
     // TODO(carl-mastrangelo): eventually remove this once all callers are updated.
@@ -89,6 +90,7 @@ public final class TransportFrameUtil {
    * @param http2Headers the interleaved keys and values of HTTP/2-compliant headers
    * @return the interleaved keys and values in the raw serialized format
    */
+  @SuppressWarnings("BetaApi") // BaseEncoding is stable in Guava 20.0
   public static byte[][] toRawSerializedHeaders(byte[][] http2Headers) {
     for (int i = 0; i < http2Headers.length; i += 2) {
       byte[] key = http2Headers[i];

interop-testing/build.gradle

@@ -32,6 +32,11 @@ dependencies {
 
 configureProtoCompilation()
 
+compileJava {
+    // This isn't a library; it can use beta APIs
+    it.options.compilerArgs += ["-Xep:BetaApi:OFF"]
+}
+
 test {
     // For the automated tests, use Jetty ALPN.
     jvmArgs "-javaagent:" + configurations.alpnagent.asPath

netty/src/main/java/io/grpc/netty/GrpcHttp2HeadersUtils.java

@@ -179,6 +179,7 @@ class GrpcHttp2HeadersUtils {
       return PlatformDependent.equals(bytes0, offset0, bytes1, offset1, length0);
     }
 
+    @SuppressWarnings("BetaApi") // BaseEncoding is stable in Guava 20.0
     private static byte[] toBinaryValue(AsciiString name, AsciiString value) {
       return name.endsWith(binaryHeaderSuffix)
           ? BaseEncoding.base64().decode(value)

netty/src/main/java/io/grpc/netty/NettyClientStream.java

@@ -111,6 +111,7 @@ class NettyClientStream extends AbstractClientStream {
   }
 
   private class Sink implements AbstractClientStream.Sink {
+    @SuppressWarnings("BetaApi") // BaseEncoding is stable in Guava 20.0
     @Override
     public void writeHeaders(Metadata headers, byte[] requestPayload) {
       // Convert the headers into Netty HTTP/2 headers.

okhttp/src/main/java/io/grpc/okhttp/OkHttpClientStream.java

@@ -126,6 +126,7 @@ class OkHttpClientStream extends AbstractClientStream {
   }
 
   class Sink implements AbstractClientStream.Sink {
+    @SuppressWarnings("BetaApi") // BaseEncoding is stable in Guava 20.0
     @Override
     public void writeHeaders(Metadata metadata, byte[] payload) {
       String defaultPath = "/" + method.getFullMethodName();

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

@@ -41,7 +41,6 @@ import static org.mockito.Mockito.when;
 
 import com.google.common.base.Objects;
 import com.google.common.collect.Lists;
-import com.google.common.io.ByteStreams;
 import com.google.common.util.concurrent.MoreExecutors;
 import com.google.common.util.concurrent.SettableFuture;
 import io.grpc.Attributes;
@@ -57,6 +56,7 @@ import io.grpc.internal.ClientStream;
 import io.grpc.internal.ClientStreamListener;
 import io.grpc.internal.ClientTransport;
 import io.grpc.internal.InternalServer;
+import io.grpc.internal.IoUtils;
 import io.grpc.internal.ManagedClientTransport;
 import io.grpc.internal.ServerListener;
 import io.grpc.internal.ServerStream;
@@ -1954,7 +1954,7 @@ public abstract class AbstractTransportTest {
     @Override
     public String parse(InputStream stream) {
       try {
-        return new String(ByteStreams.toByteArray(stream), UTF_8);
+        return new String(IoUtils.toByteArray(stream), UTF_8);
       } catch (IOException ex) {
         throw new RuntimeException(ex);
       }