Make ServerValue.increment() public (#1417)

Author: schmidt-sebastian

firebase-database/CHANGELOG.md

@@ -1,3 +1,7 @@
+# Unreleased
+- [feature] Added ServerValue.increment() to support atomic field value increments
+  without transactions.
+
 # 19.2.0
 - [changed] Added support for type wildcards in GenericTypeIndicator, expanding
   our custom class serialization to include classes with wildcard generics

firebase-database/api.txt

@@ -188,6 +188,8 @@ package com.google.firebase.database {
   public class ServerValue {
     ctor public ServerValue();
     field @NonNull public static final java.util.Map<java.lang.String,java.lang.String> TIMESTAMP;
+    field @NonNull public static final Object increment(double);
+    field @NonNull public static final Object increment(long);
   }
 
   @java.lang.annotation.Retention(java.lang.annotation.RetentionPolicy.RUNTIME) @java.lang.annotation.Target({java.lang.annotation.ElementType.TYPE}) public @interface ThrowOnExtraProperties {

firebase-database/src/main/java/com/google/firebase/database/ServerValue.java

@@ -34,7 +34,8 @@ public class ServerValue {
       createScalarServerValuePlaceholder(ServerValues.NAME_OP_TIMESTAMP);
 
   /**
-   * Adds the given delta to the current value at a location.
+   * Returns a placeholder value that can be used to atomically increment the current database value
+   * by the provided delta.
    *
    * <p>The delta must be an long or a double value. If the current value is not an integer or
    * double, or if the data does not yet exist, the transformation will set the data to the delta
@@ -46,12 +47,13 @@ public class ServerValue {
    * @return a placeholder value for modifying data atomically server-side.
    */
   @NonNull
-  static final Object increment(long delta) {
+  public static final Object increment(long delta) {
     return createParameterizedServerValuePlaceholder(ServerValues.NAME_OP_INCREMENT, delta);
   }
 
   /**
-   * Adds the given delta to the current value at a location.
+   * Returns a placeholder value that can be used to atomically increment the current database value
+   * by the provided delta.
    *
    * <p>The delta must be an long or a double value. If the current value is not an integer or
    * double, or if the data does not yet exist, the transformation will set the data to the delta
@@ -63,7 +65,7 @@ static final Object increment(long delta) {
    * @return a placeholder value for modifying data atomically server-side.
    */
   @NonNull
-  static final Object increment(double delta) {
+  public static final Object increment(double delta) {
     return createParameterizedServerValuePlaceholder(ServerValues.NAME_OP_INCREMENT, delta);
   }