Implement IterableProtoSubject.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=137572300

extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FieldScopeImpl.java

@@ -23,9 +23,11 @@
 import com.google.common.base.Function;
 import com.google.common.base.Functions;
 import com.google.common.base.Optional;
+import com.google.common.collect.Lists;
 import com.google.protobuf.Descriptors.Descriptor;
 import com.google.protobuf.Descriptors.FieldDescriptor;
 import com.google.protobuf.Message;
+import java.util.List;
 
 /**
  * Implementation of a {@link FieldScope}. It takes a logic component {@link FieldScopeLogic}, and
@@ -75,7 +77,7 @@ static FieldScope createFromSetFields(Iterable<? extends Message> messages) {
     checkArgument(
         optDescriptor.isPresent(),
         "Cannot create scope from messages with different descriptors: %s",
-        messages);
+        getDescriptors(messages));
 
     Message.Builder builder = null;
     for (Message message : messages) {
@@ -90,7 +92,7 @@ static FieldScope createFromSetFields(Iterable<? extends Message> messages) {
 
     return create(
         FieldScopeLogic.partialScope(builder.build()),
-        Functions.constant(String.format("FieldScopes.fromSetFields(%s)", messages.toString())));
+        Functions.constant(String.format("FieldScopes.fromSetFields(%s)", formatList(messages))));
   }
 
   static FieldScope createIgnoringFields(int... fieldNumbers) {
@@ -180,12 +182,6 @@ public final FieldScope allowingFieldDescriptors(FieldDescriptor... fieldDescrip
             ".allowingFieldDescriptors(%s)", fieldDescriptors));
   }
 
-  private Function<Optional<Descriptor>, String> addUsingCorrespondenceString(
-      String fmt, Object... args) {
-    return FieldScopeUtil.concat(
-        usingCorrespondenceStringFunction(), Functions.constant(String.format(fmt, args)));
-  }
-
   private Function<Optional<Descriptor>, String> addUsingCorrespondenceFieldNumbersString(
       String fmt, int... fieldNumbers) {
     return FieldScopeUtil.concat(
@@ -199,4 +195,20 @@ private Function<Optional<Descriptor>, String> addUsingCorrespondenceFieldDescri
         usingCorrespondenceStringFunction(),
         Functions.constant(String.format(fmt, join(fieldDescriptors))));
   }
+
+  private static Iterable<String> getDescriptors(Iterable<? extends Message> messages) {
+    List<String> descriptors = Lists.newArrayList();
+    for (Message message : messages) {
+      descriptors.add(message == null ? "null" : message.getDescriptorForType().getFullName());
+    }
+    return descriptors;
+  }
+
+  private static String formatList(Iterable<? extends Message> messages) {
+    List<String> strings = Lists.newArrayList();
+    for (Message message : messages) {
+      strings.add(message == null ? "null" : "{" + message + "}");
+    }
+    return "[" + join(strings) + "]";
+  }
 }

extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FieldScopeLogic.java

@@ -331,8 +331,8 @@ void validate(Descriptor descriptor) {
           expectedDescriptor.equals(descriptor),
           "Message given to FieldScopes.fromSetFields() does not have the same descriptor as the "
               + "message being tested. Expected %s, got %s.",
-          expectedDescriptor,
-          descriptor);
+          expectedDescriptor.getFullName(),
+          descriptor.getFullName());
     }
 
     @Override

extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FieldScopeUtil.java

@@ -23,6 +23,8 @@
 import com.google.protobuf.Descriptors.Descriptor;
 import com.google.protobuf.Descriptors.FieldDescriptor;
 import com.google.protobuf.Message;
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
 /** Utility methods for {@link FieldScope}s and {@link FluentEqualityConfig}. */
@@ -92,6 +94,15 @@ static Optional<Descriptor> getSingleDescriptor(Iterable<? extends Message> mess
     return optDescriptor;
   }
 
+  /** Joins the arguments into a {@link List} for convenience. */
+  static <T> List<T> makeList(T first, T second, T... rest) {
+    List<T> list = new ArrayList<T>();
+    list.add(first);
+    list.add(second);
+    list.addAll(Arrays.asList(rest));
+    return list;
+  }
+
   private static final Joiner JOINER = Joiner.on(", ");
 
   static String join(int... fieldNumbers) {
@@ -121,7 +132,7 @@ private static String resolveFieldNumbers(
         FieldDescriptor field = descriptor.findFieldByNumber(fieldNumber);
         strings.add(field != null ? field.toString() : String.format("%d (?)", fieldNumber));
       }
-      return join(strings);
+      return String.format(fmt, join(strings));
     } else {
       return String.format(fmt, join(fieldNumbers));
     }

extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FieldScopes.java

@@ -73,8 +73,19 @@ public static FieldScope fromSetFields(Message message) {
    * <p>This can be thought of as the union of the {@link FieldScope}s for each individual message,
    * or the {@link FieldScope} for the merge of all the messages. These are equivalent.
    */
-  // TODO(user): Make public when IterableProtoSubject is exposed and this has valid use.
-  private static FieldScope fromSetFields(Iterable<? extends Message> messages) {
+  public static FieldScope fromSetFields(
+      Message firstMessage, Message secondMessage, Message... rest) {
+    return fromSetFields(FieldScopeUtil.makeList(firstMessage, secondMessage, rest));
+  }
+
+  /**
+   * Creates a {@link FieldScope} convering the fields set in every message in the provided list of
+   * messages, with the same semantics as in {@link #fromSetFields(Message)}.
+   *
+   * <p>This can be thought of as the union of the {@link FieldScope}s for each individual message,
+   * or the {@link FieldScope} for the merge of all the messages. These are equivalent.
+   */
+  public static FieldScope fromSetFields(Iterable<? extends Message> messages) {
     return FieldScopeImpl.createFromSetFields(messages);
   }
 

extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FluentEqualityConfig.java

@@ -160,11 +160,11 @@ final MessageDifferencer toMessageDifferencer(Descriptor descriptor) {
     return messageDifferencers.getUnchecked(descriptor);
   }
 
-  final Correspondence<Message, Message> toCorrespondence(
+  final <M extends Message> Correspondence<M, M> toCorrespondence(
       final Optional<Descriptor> optDescriptor) {
-    return new Correspondence<Message, Message>() {
+    return new Correspondence<M, M>() {
       @Override
-      public final boolean compare(@Nullable Message actual, @Nullable Message expected) {
+      public final boolean compare(@Nullable M actual, @Nullable M expected) {
         return ProtoTruth.assertThat(actual)
             .usingConfig(FluentEqualityConfig.this)
             .testIsEqualTo(expected);