Adding FieldValue.increment() (#4018)

* DO NOT MERGE: Adding FieldValue.increment()

* Use "increment" Proto naming

google-cloud-clients/google-cloud-firestore/src/main/java/com/google/cloud/firestore/FieldValue.java

@@ -77,6 +77,55 @@ FieldTransform toProto(FieldPath path) {
         }
       };
 
+  static class NumericIncrementFieldValue extends FieldValue {
+    final Number operand;
+
+    NumericIncrementFieldValue(Number operand) {
+      this.operand = operand;
+    }
+
+    @Override
+    boolean includeInDocumentMask() {
+      return false;
+    }
+
+    @Override
+    boolean includeInDocumentTransform() {
+      return true;
+    }
+
+    @Override
+    String getMethodName() {
+      return "FieldValue.increment()";
+    }
+
+    @Override
+    FieldTransform toProto(FieldPath path) {
+      FieldTransform.Builder fieldTransform = FieldTransform.newBuilder();
+      fieldTransform.setFieldPath(path.getEncodedPath());
+      fieldTransform.setIncrement(
+          UserDataConverter.encodeValue(path, operand, UserDataConverter.ARGUMENT));
+      return fieldTransform.build();
+    }
+
+    @Override
+    public boolean equals(Object o) {
+      if (this == o) {
+        return true;
+      }
+      if (o == null || getClass() != o.getClass()) {
+        return false;
+      }
+      NumericIncrementFieldValue that = (NumericIncrementFieldValue) o;
+      return Objects.equals(operand, that.operand);
+    }
+
+    @Override
+    public int hashCode() {
+      return Objects.hash(operand);
+    }
+  }
+
   static class ArrayUnionFieldValue extends FieldValue {
     final List<Object> elements;
 
@@ -205,11 +254,44 @@ public static FieldValue delete() {
   }
 
   /**
-   * Returns a special value that can be used with set() or update() that tells the server to union
-   * the given elements with any array value that already exists on the server. Each specified
-   * element that doesn't already exist in the array will be added to the end. If the field being
-   * modified is not already an array it will be overwritten with an array containing exactly the
-   * specified elements.
+   * Returns a special value that can be used with set(), create() or update() that tells the server
+   * to increment the field's current value by the given value.
+   *
+   * <p>If the current field value is an integer, possible integer overflows are resolved to
+   * Long.MAX_VALUE or Long.MIN_VALUE. If the current field value is a double, both values will be
+   * interpreted as doubles and the arithmetic will follow IEEE 754 semantics.
+   *
+   * <p>If the current field is not an integer or double, or if the field does not yet exist, the
+   * transformation will set the field to the given value.
+   *
+   * @return The FieldValue sentinel for use in a call to set(), create() or update().
+   */
+  @Nonnull
+  public static FieldValue increment(long l) {
+    return new NumericIncrementFieldValue(l);
+  }
+
+  /**
+   * Returns a special value that can be used with set(), create() or update() that tells the server
+   * to increment the field's current value by the given value.
+   *
+   * <p>If the current value is an integer or a double, both the current and the given value will be
+   * interpreted as doubles and all arithmetic will follow IEEE 754 semantics. Otherwise, the
+   * transformation will set the field to the given value.
+   *
+   * @return The FieldValue sentinel for use in a call to set(), create() or update().
+   */
+  @Nonnull
+  public static FieldValue increment(double d) {
+    return new NumericIncrementFieldValue(d);
+  }
+
+  /**
+   * Returns a special value that can be used with set(), create() or update() that tells the server
+   * to union the given elements with any array value that already exists on the server. Each
+   * specified element that doesn't already exist in the array will be added to the end. If the
+   * field being modified is not already an array it will be overwritten with an array containing
+   * exactly the specified elements.
    *
    * @param elements The elements to union into the array.
    * @return The FieldValue sentinel for use in a call to set() or update().
@@ -221,10 +303,10 @@ public static FieldValue arrayUnion(@Nonnull Object... elements) {
   }
 
   /**
-   * Returns a special value that can be used with set() or update() that tells the server to remove
-   * the given elements from any array value that already exists on the server. All instances of
-   * each element specified will be removed from the array. If the field being modified is not
-   * already an array it will be overwritten with an empty array.
+   * Returns a special value that can be used with set(), create() or update() that tells the server
+   * to remove the given elements from any array value that already exists on the server. All
+   * instances of each element specified will be removed from the array. If the field being modified
+   * is not already an array it will be overwritten with an empty array.
    *
    * @param elements The elements to remove from the array.
    * @return The FieldValue sentinel for use in a call to set() or update().

google-cloud-clients/google-cloud-firestore/src/main/java/com/google/cloud/firestore/UserDataConverter.java

@@ -90,7 +90,7 @@ private UserDataConverter() {}
    * @param path path THe field path of the object to encode.
    * @param sanitizedObject An Object that has been sanitized by CustomClassMapper and only contains
    *     valid types.
-   * @param options Encoding opions to use for this value.
+   * @param options Encoding options to use for this value.
    * @return The Value proto.
    */
   @Nullable

google-cloud-clients/google-cloud-firestore/src/test/java/com/google/cloud/firestore/DocumentReferenceTest.java

@@ -44,6 +44,7 @@
 import static com.google.cloud.firestore.LocalFirestoreHelper.delete;
 import static com.google.cloud.firestore.LocalFirestoreHelper.get;
 import static com.google.cloud.firestore.LocalFirestoreHelper.getAllResponse;
+import static com.google.cloud.firestore.LocalFirestoreHelper.increment;
 import static com.google.cloud.firestore.LocalFirestoreHelper.map;
 import static com.google.cloud.firestore.LocalFirestoreHelper.object;
 import static com.google.cloud.firestore.LocalFirestoreHelper.serverTimestamp;
@@ -408,6 +409,30 @@ public void mergeWithServerTimestamps() throws Exception {
     assertCommitEquals(set, commitRequests.get(1));
   }
 
+  @Test
+  public void setWithIncrement() throws Exception {
+    doReturn(FIELD_TRANSFORM_COMMIT_RESPONSE)
+        .when(firestoreMock)
+        .sendRequest(
+            commitCapture.capture(), Matchers.<UnaryCallable<CommitRequest, CommitResponse>>any());
+
+    documentReference
+        .set(map("integer", FieldValue.increment(1), "double", FieldValue.increment(1.1)))
+        .get();
+
+    CommitRequest set =
+        commit(
+            set(Collections.<String, Value>emptyMap()),
+            transform(
+                "integer",
+                increment(Value.newBuilder().setIntegerValue(1).build()),
+                "double",
+                increment(Value.newBuilder().setDoubleValue(1.1).build())));
+
+    CommitRequest commitRequest = commitCapture.getValue();
+    assertCommitEquals(set, commitRequest);
+  }
+
   @Test
   public void setWithArrayUnion() throws Exception {
     doReturn(FIELD_TRANSFORM_COMMIT_RESPONSE)

google-cloud-clients/google-cloud-firestore/src/test/java/com/google/cloud/firestore/FirestoreTest.java

@@ -157,4 +157,16 @@ public void arrayRemoveEquals() {
     assertNotEquals(arrayRemove1, arrayRemove3);
     assertNotEquals(arrayRemove1, arrayUnion);
   }
+
+  @Test
+  public void incrementEquals() {
+    FieldValue increment1 = FieldValue.increment(42);
+    FieldValue increment2 = FieldValue.increment(42);
+    FieldValue increment3 = FieldValue.increment(42.0);
+    FieldValue increment4 = FieldValue.increment(42.0);
+    assertEquals(increment1, increment2);
+    assertEquals(increment3, increment4);
+    assertNotEquals(increment1, increment3);
+    assertNotEquals(increment2, increment4);
+  }
 }

google-cloud-clients/google-cloud-firestore/src/test/java/com/google/cloud/firestore/LocalFirestoreHelper.java

@@ -272,6 +272,10 @@ public static FieldTransform serverTimestamp() {
         .build();
   }
 
+  public static FieldTransform increment(Value value) {
+    return FieldTransform.newBuilder().setIncrement(value).build();
+  }
+
   public static FieldTransform arrayUnion(Value... values) {
     return FieldTransform.newBuilder()
         .setAppendMissingElements(ArrayValue.newBuilder().addAllValues(Arrays.asList(values)))

google-cloud-clients/google-cloud-firestore/src/test/java/com/google/cloud/firestore/it/ITSystemTest.java

@@ -71,6 +71,8 @@
 
 public class ITSystemTest {
 
+  private static final double DOUBLE_EPSILON = 0.000001;
+
   private final Map<String, Object> SINGLE_FIELD_MAP = LocalFirestoreHelper.SINGLE_FIELD_MAP;
   private final Map<String, Object> ALL_SUPPORTED_TYPES_MAP =
       LocalFirestoreHelper.ALL_SUPPORTED_TYPES_MAP;
@@ -977,4 +979,22 @@ public void arrayOperators() throws ExecutionException, InterruptedException {
 
     assertTrue(containsQuery.get().get().isEmpty());
   }
+
+  @Test
+  public void integerIncrement() throws ExecutionException, InterruptedException {
+    DocumentReference docRef = randomColl.document();
+    docRef.set(Collections.singletonMap("sum", (Object) 1L)).get();
+    docRef.update("sum", FieldValue.increment(2)).get();
+    DocumentSnapshot docSnap = docRef.get().get();
+    assertEquals(3L, docSnap.get("sum"));
+  }
+
+  @Test
+  public void floatIncrement() throws ExecutionException, InterruptedException {
+    DocumentReference docRef = randomColl.document();
+    docRef.set(Collections.singletonMap("sum", (Object) 1.1)).get();
+    docRef.update("sum", FieldValue.increment(2.2)).get();
+    DocumentSnapshot docSnap = docRef.get().get();
+    assertEquals(3.3, (Double) docSnap.get("sum"), DOUBLE_EPSILON);
+  }
 }