Exposing message list limit for external usage

src/main/java/com/google/firebase/messaging/FirebaseMessaging.java

@@ -41,6 +41,8 @@
  */
 public class FirebaseMessaging {
 
+  public static final int MAX_MESSAGES_IN_LIST = 500;
+
   private final FirebaseApp app;
   private final Supplier<? extends FirebaseMessagingClient> messagingClient;
   private final Supplier<? extends InstanceIdClient> instanceIdClient;
@@ -147,7 +149,8 @@ protected String execute() throws FirebaseMessagingException {
    * <p>The responses list obtained by calling {@link BatchResponse#getResponses()} on the return
    * value corresponds to the order of input messages.
    *
-   * @param messages A non-null, non-empty list containing up to 500 messages.
+   * @param messages A non-null, non-empty list containing up to {@value #MAX_MESSAGES_IN_LIST}
+   *                 messages.
    * @return A {@link BatchResponse} indicating the result of the operation.
    * @throws FirebaseMessagingException If an error occurs while handing the messages off to FCM for
    *     delivery. An exception here indicates a total failure -- i.e. none of the messages in the
@@ -171,7 +174,8 @@ public BatchResponse sendAll(
    * <p>The responses list obtained by calling {@link BatchResponse#getResponses()} on the return
    * value corresponds to the order of input messages.
    *
-   * @param messages A non-null, non-empty list containing up to 500 messages.
+   * @param messages A non-null, non-empty list containing up to {@value #MAX_MESSAGES_IN_LIST}
+   *                 messages.
    * @param dryRun A boolean indicating whether to perform a dry run (validation only) of the send.
    * @return A {@link BatchResponse} indicating the result of the operation.
    * @throws FirebaseMessagingException If an error occurs while handing the messages off to FCM for
@@ -186,7 +190,8 @@ public BatchResponse sendAll(
   /**
    * Similar to {@link #sendAll(List)} but performs the operation asynchronously.
    *
-   * @param messages A non-null, non-empty list containing up to 500 messages.
+   * @param messages A non-null, non-empty list containing up to {@value #MAX_MESSAGES_IN_LIST}
+   *                 messages.
    * @return @return An {@code ApiFuture} that will complete with a {@link BatchResponse} when
    *     the messages have been sent.
    */
@@ -197,7 +202,8 @@ public ApiFuture<BatchResponse> sendAllAsync(@NonNull List<Message> messages) {
   /**
    * Similar to {@link #sendAll(List, boolean)} but performs the operation asynchronously.
    *
-   * @param messages A non-null, non-empty list containing up to 500 messages.
+   * @param messages A non-null, non-empty list containing up to {@value #MAX_MESSAGES_IN_LIST}
+   *                 messages.
    * @param dryRun A boolean indicating whether to perform a dry run (validation only) of the send.
    * @return @return An {@code ApiFuture} that will complete with a {@link BatchResponse} when
    *     the messages have been sent, or when the emulation has finished.
@@ -286,8 +292,8 @@ private CallableOperation<BatchResponse, FirebaseMessagingException> sendAllOp(
 
     final List<Message> immutableMessages = ImmutableList.copyOf(messages);
     checkArgument(!immutableMessages.isEmpty(), "messages list must not be empty");
-    checkArgument(immutableMessages.size() <= 500,
-        "messages list must not contain more than 500 elements");
+    checkArgument(immutableMessages.size() <= MAX_MESSAGES_IN_LIST,
+        "messages list must not contain more than " + MAX_MESSAGES_IN_LIST + " elements");
     final FirebaseMessagingClient messagingClient = getMessagingClient();
     return new CallableOperation<BatchResponse,FirebaseMessagingException>() {
       @Override

src/main/java/com/google/firebase/messaging/MulticastMessage.java

@@ -17,6 +17,7 @@
 package com.google.firebase.messaging;
 
 import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.firebase.messaging.FirebaseMessaging.MAX_MESSAGES_IN_LIST;
 
 import com.google.api.client.util.Strings;
 import com.google.common.collect.ImmutableList;
@@ -31,7 +32,8 @@
 /**
  * Represents a message that can be sent to multiple devices via Firebase Cloud Messaging (FCM).
  * Contains payload information as well as the list of device registration tokens to which the
- * message should be sent. A single {@code MulticastMessage} may contain up to 500 registration
+ * message should be sent. A single {@code MulticastMessage} may contain up to
+ * {@value com.google.firebase.messaging.FirebaseMessaging#MAX_MESSAGES_IN_LIST} registration
  * tokens.
  *
  * <p>Instances of this class are thread-safe and immutable. Use {@link MulticastMessage.Builder}
@@ -56,7 +58,8 @@ public class MulticastMessage {
   private MulticastMessage(Builder builder) {
     this.tokens = builder.tokens.build();
     checkArgument(!this.tokens.isEmpty(), "at least one token must be specified");
-    checkArgument(this.tokens.size() <= 500, "no more than 500 tokens can be specified");
+    checkArgument(this.tokens.size() <= MAX_MESSAGES_IN_LIST, "no more than "
+            + MAX_MESSAGES_IN_LIST + " tokens can be specified");
     for (String token : this.tokens) {
       checkArgument(!Strings.isNullOrEmpty(token), "none of the tokens can be null or empty");
     }
@@ -107,8 +110,9 @@ public static class Builder {
     private Builder() {}
 
     /**
-     * Adds a token to which the message should be sent. Up to 500 tokens can be specified on
-     * a single instance of {@link MulticastMessage}.
+     * Adds a token to which the message should be sent.
+     * Up to {@value com.google.firebase.messaging.FirebaseMessaging#MAX_MESSAGES_IN_LIST}
+     * tokens can be specified on a single instance of {@link MulticastMessage}.
      *
      * @param token A non-null, non-empty Firebase device registration token.
      * @return This builder.
@@ -119,8 +123,9 @@ public Builder addToken(@NonNull String token) {
     }
 
     /**
-     * Adds a collection of tokens to which the message should be sent. Up to 500 tokens can be
-     * specified on a single instance of {@link MulticastMessage}.
+     * Adds a collection of tokens to which the message should be sent.
+     * Up to {@value com.google.firebase.messaging.FirebaseMessaging#MAX_MESSAGES_IN_LIST}
+     * tokens can be specified on a single instance of {@link MulticastMessage}.
      *
      * @param tokens Collection of Firebase device registration tokens.
      * @return This builder.

src/test/java/com/google/firebase/messaging/FirebaseMessagingIT.java

@@ -16,6 +16,7 @@
 
 package com.google.firebase.messaging;
 
+import static com.google.firebase.messaging.FirebaseMessaging.MAX_MESSAGES_IN_LIST;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
@@ -147,16 +148,16 @@ public void testSendAll() throws Exception {
   }
 
   @Test
-  public void testSendFiveHundred() throws Exception {
+  public void testSendMaximumAmountOfMessages() throws Exception {
     List<Message> messages = new ArrayList<>();
-    for (int i = 0; i < 500; i++) {
+    for (int i = 0; i < MAX_MESSAGES_IN_LIST; i++) {
       messages.add(Message.builder().setTopic("foo-bar-" + (i % 10)).build());
     }
 
     BatchResponse response = FirebaseMessaging.getInstance().sendAll(messages, true);
 
-    assertEquals(500, response.getResponses().size());
-    assertEquals(500, response.getSuccessCount());
+    assertEquals(MAX_MESSAGES_IN_LIST, response.getResponses().size());
+    assertEquals(MAX_MESSAGES_IN_LIST, response.getSuccessCount());
     assertEquals(0, response.getFailureCount());
     for (SendResponse sendResponse : response.getResponses()) {
       if (!sendResponse.isSuccessful()) {

src/test/java/com/google/firebase/messaging/FirebaseMessagingTest.java

@@ -16,6 +16,7 @@
 
 package com.google.firebase.messaging;
 
+import static com.google.firebase.messaging.FirebaseMessaging.MAX_MESSAGES_IN_LIST;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNull;
@@ -297,7 +298,7 @@ public void testSendAllWithTooManyMessages() throws FirebaseMessagingException {
     MockFirebaseMessagingClient client = MockFirebaseMessagingClient.fromMessageId(null);
     FirebaseMessaging messaging = getMessagingForSend(Suppliers.ofInstance(client));
     ImmutableList.Builder<Message> listBuilder = ImmutableList.builder();
-    for (int i = 0; i < 501; i++) {
+    for (int i = 0; i < MAX_MESSAGES_IN_LIST + 1; i++) {
       listBuilder.add(Message.builder().setTopic("topic").build());
     }
 

src/test/java/com/google/firebase/messaging/MulticastMessageTest.java

@@ -16,6 +16,7 @@
 
 package com.google.firebase.messaging;
 
+import static com.google.firebase.messaging.FirebaseMessaging.MAX_MESSAGES_IN_LIST;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertSame;
 import static org.junit.Assert.fail;
@@ -75,7 +76,7 @@ public void testNoTokens() {
   @Test
   public void testTooManyTokens() {
     MulticastMessage.Builder builder = MulticastMessage.builder();
-    for (int i = 0; i < 501; i++) {
+    for (int i = 0; i < MAX_MESSAGES_IN_LIST + 1; i++) {
       builder.addToken("token" + i);
     }
     try {