Change timestampsInSnapshots default to true and deprecate the setting. (#190)

Change timestampsInSnapshots default to true and deprecate the setting.

Author: mikelehen

firebase-firestore/src/androidTest/java/com/google/firebase/firestore/FieldsTest.java

@@ -217,8 +217,6 @@ private static Map<String, Object> objectWithTimestamp(Timestamp timestamp) {
     return map("timestamp", timestamp, "nested", map("timestamp2", timestamp));
   }
 
-  // Note: because timestampsInSnapshotsEnabled is set to true in default test settings, this test
-  // is unaffected by the current default value in FirebaseFirestoreSettings.
   @Test
   public void testTimestampsInSnapshots() {
     Timestamp originalTimestamp = new Timestamp(100, 123456789);

firebase-firestore/src/androidTest/java/com/google/firebase/firestore/testutil/IntegrationTestUtil.java

@@ -91,6 +91,7 @@ public static FirebaseFirestoreSettings newTestSettings() {
     return newTestSettingsWithSnapshotTimestampsEnabled(true);
   }
 
+  @SuppressWarnings("deprecation") // for setTimestampsInSnapshotsEnabled()
   public static FirebaseFirestoreSettings newTestSettingsWithSnapshotTimestampsEnabled(
       boolean enabled) {
     return new FirebaseFirestoreSettings.Builder()

firebase-firestore/src/main/java/com/google/firebase/firestore/FirebaseFirestore.java

@@ -186,36 +186,6 @@ private void ensureClientConfigured() {
       if (client != null) {
         return;
       }
-      if (!settings.areTimestampsInSnapshotsEnabled()) {
-        Logger.warn(
-            "Firestore",
-            "The behavior for java.util.Date objects stored in Firestore is going to change "
-                + "AND YOUR APP MAY BREAK.\n"
-                + "To hide this warning and ensure your app does not break, you need to add "
-                + "the following code to your app before calling any other Cloud Firestore "
-                + "methods:\n"
-                + "\n"
-                + "FirebaseFirestore firestore = FirebaseFirestore.getInstance();\n"
-                + "FirebaseFirestoreSettings settings = new FirebaseFirestoreSettings.Builder()\n"
-                + "    .setTimestampsInSnapshotsEnabled(true)\n"
-                + "    .build();\n"
-                + "firestore.setFirestoreSettings(settings);\n"
-                + "\n"
-                + "With this change, timestamps stored in Cloud Firestore will be read back as "
-                + "com.google.firebase.Timestamp objects instead of as system java.util.Date "
-                + "objects. So you will also need to update code expecting a java.util.Date to "
-                + "instead expect a Timestamp. For example:\n"
-                + "\n"
-                + "// Old:\n"
-                + "java.util.Date date = snapshot.getDate(\"created_at\");\n"
-                + "// New:\n"
-                + "Timestamp timestamp = snapshot.getTimestamp(\"created_at\");\n"
-                + "java.util.Date date = timestamp.toDate();\n"
-                + "\n"
-                + "Please audit all existing usages of java.util.Date when you enable the new "
-                + "behavior. In a future release, the behavior will be changed to the new "
-                + "behavior, so if you do not follow these steps, YOUR APP MAY BREAK.");
-      }
       DatabaseInfo databaseInfo =
           new DatabaseInfo(databaseId, persistenceKey, settings.getHost(), settings.isSslEnabled());
 

firebase-firestore/src/main/java/com/google/firebase/firestore/FirebaseFirestoreSettings.java

@@ -37,7 +37,7 @@ public final class FirebaseFirestoreSettings {
   // we will switch the default to the above value, 100 MB.
   private static final long DEFAULT_CACHE_SIZE_BYTES = CACHE_SIZE_UNLIMITED;
   private static final String DEFAULT_HOST = "firestore.googleapis.com";
-  private static final boolean DEFAULT_TIMESTAMPS_IN_SNAPSHOTS_ENABLED = false;
+  private static final boolean DEFAULT_TIMESTAMPS_IN_SNAPSHOTS_ENABLED = true;
 
   /** A Builder for creating {@link FirebaseFirestoreSettings}. */
   @PublicApi
@@ -110,28 +110,27 @@ public Builder setPersistenceEnabled(boolean value) {
     }
 
     /**
-     * Enables the use of {@link com.google.firebase.Timestamp Timestamps} for timestamp fields in
-     * {@link DocumentSnapshot DocumentSnapshots}.
+     * Specifies whether to use {@link com.google.firebase.Timestamp Timestamps} for timestamp
+     * fields in {@link DocumentSnapshot DocumentSnapshots}. This is now enabled by default and
+     * should not be disabled.
      *
-     * <p>Currently, Firestore returns timestamp fields as {@link java.util.Date} but {@link
-     * java.util.Date Date} only supports millisecond precision, which leads to truncation and
-     * causes unexpected behavior when using a timestamp from a snapshot as a part of a subsequent
-     * query.
+     * <p>Previously, Firestore returned timestamp fields as {@link java.util.Date} but {@link
+     * java.util.Date} only supports millisecond precision, which leads to truncation and causes
+     * unexpected behavior when using a timestamp from a snapshot as a part of a subsequent query.
      *
-     * <p>Setting {@code setTimestampsInSnapshotsEnabled(true)} will cause Firestore to return
-     * {@link com.google.firebase.Timestamp Timestamp} values instead of {@link java.util.Date
-     * Date}, avoiding this kind of problem. To make this work you must also change any code that
-     * uses {@link java.util.Date Date} to use {@link com.google.firebase.Timestamp Timestamp}
-     * instead.
+     * <p>So now Firestore returns {@link com.google.firebase.Timestamp Timestamp} values instead of
+     * {@link java.util.Date}, avoiding this kind of problem.
      *
-     * <p>NOTE: in the future {@link FirebaseFirestoreSettings#areTimestampsInSnapshotsEnabled} will
-     * default to true and this option will be removed so you should change your code to use
-     * Timestamp now and opt-in to this new behavior as soon as you can.
+     * <p>To opt into the old behavior of returning {@link java.util.Date Dates}, you can
+     * temporarily set {@link FirebaseFirestoreSettings#areTimestampsInSnapshotsEnabled} to false.
      *
-     * @return A settings object on which the return type for timestamp fields is configured as
-     *     specified by the given {@code value}.
+     * @deprecated This setting now defaults to true and will be removed in a future release. If you
+     *     are already setting it to true, just remove the setting. If you are setting it to false,
+     *     you should update your code to expect {@link com.google.firebase.Timestamp Timestamps}
+     *     instead of {@link java.util.Date Dates} and then remove the setting.
      */
     @NonNull
+    @Deprecated
     @PublicApi
     public Builder setTimestampsInSnapshotsEnabled(boolean value) {
       this.timestampsInSnapshotsEnabled = value;