feature(firestore): added minimum and maximum FieldValue operations

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

@@ -127,6 +127,104 @@ public int hashCode() {
     }
   }
 
+  static class NumericMinimumFieldValue extends FieldValue {
+    final Number operand;
+
+    NumericMinimumFieldValue(Number operand) {
+      this.operand = operand;
+    }
+
+    @Override
+    boolean includeInDocumentMask() {
+      return false;
+    }
+
+    @Override
+    boolean includeInDocumentTransform() {
+      return true;
+    }
+
+    @Override
+    String getMethodName() {
+      return "FieldValue.minimum()";
+    }
+
+    @Override
+    FieldTransform toProto(FieldPath path) {
+      FieldTransform.Builder fieldTransform = FieldTransform.newBuilder();
+      fieldTransform.setFieldPath(path.getEncodedPath());
+      fieldTransform.setMinimum(
+          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;
+      }
+      NumericMinimumFieldValue that = (NumericMinimumFieldValue) o;
+      return Objects.equals(operand, that.operand);
+    }
+
+    @Override
+    public int hashCode() {
+      return Objects.hash(operand);
+    }
+  }
+
+  static class NumericMaximumFieldValue extends FieldValue {
+    final Number operand;
+
+    NumericMaximumFieldValue(Number operand) {
+      this.operand = operand;
+    }
+
+    @Override
+    boolean includeInDocumentMask() {
+      return false;
+    }
+
+    @Override
+    boolean includeInDocumentTransform() {
+      return true;
+    }
+
+    @Override
+    String getMethodName() {
+      return "FieldValue.maximum()";
+    }
+
+    @Override
+    FieldTransform toProto(FieldPath path) {
+      FieldTransform.Builder fieldTransform = FieldTransform.newBuilder();
+      fieldTransform.setFieldPath(path.getEncodedPath());
+      fieldTransform.setMaximum(
+          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;
+      }
+      NumericMaximumFieldValue that = (NumericMaximumFieldValue) o;
+      return Objects.equals(operand, that.operand);
+    }
+
+    @Override
+    public int hashCode() {
+      return Objects.hash(operand);
+    }
+  }
+
   static class ArrayUnionFieldValue extends FieldValue {
     final List<Object> elements;
 
@@ -289,6 +387,62 @@ 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 set the field to the numeric minimum of the field's current and the given value.
+   *
+   * <p>If the current field value is not of type 'number', 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 minimum(long l) {
+    return new NumericMinimumFieldValue(l);
+  }
+
+  /**
+   * Returns a special value that can be used with set(), create() or update() that tells the server
+   * to set the field to the numeric minimum of the field's current and the given value.
+   *
+   * <p>If the current field value is not of type 'number', 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 minimum(double d) {
+    return new NumericMinimumFieldValue(d);
+  }
+
+  /**
+   * Returns a special value that can be used with set(), create() or update() that tells the server
+   * to set the field to the numeric maximum of the field's current and the given value.
+   *
+   * <p>If the current field value is not of type 'number', 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 maximum(long l) {
+    return new NumericMaximumFieldValue(l);
+  }
+
+  /**
+   * Returns a special value that can be used with set(), create() or update() that tells the server
+   * to set the field to the numeric maximum of the field's current and the given value.
+   *
+   * <p>If the current field value is not of type 'number', 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 maximum(double d) {
+    return new NumericMaximumFieldValue(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

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

@@ -48,6 +48,8 @@
 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.maximum;
+import static com.google.cloud.firestore.LocalFirestoreHelper.minimum;
 import static com.google.cloud.firestore.LocalFirestoreHelper.object;
 import static com.google.cloud.firestore.LocalFirestoreHelper.serverTimestamp;
 import static com.google.cloud.firestore.LocalFirestoreHelper.set;
@@ -530,6 +532,56 @@ public void setWithIncrement() throws Exception {
     assertCommitEquals(set, commitRequest);
   }
 
+  @Test
+  public void setWithMinimum() throws Exception {
+    doReturn(FIELD_TRANSFORM_COMMIT_RESPONSE)
+        .when(firestoreMock)
+        .sendRequest(
+            commitCapture.capture(),
+            ArgumentMatchers.<UnaryCallable<CommitRequest, CommitResponse>>any());
+
+    documentReference
+        .set(map("integer", FieldValue.minimum(1), "double", FieldValue.minimum(1.1)))
+        .get();
+
+    CommitRequest set =
+        commit(
+            set(Collections.emptyMap()),
+            transform(
+                "integer",
+                minimum(Value.newBuilder().setIntegerValue(1).build()),
+                "double",
+                minimum(Value.newBuilder().setDoubleValue(1.1).build())));
+
+    CommitRequest commitRequest = commitCapture.getValue();
+    assertCommitEquals(set, commitRequest);
+  }
+
+  @Test
+  public void setWithMaximum() throws Exception {
+    doReturn(FIELD_TRANSFORM_COMMIT_RESPONSE)
+        .when(firestoreMock)
+        .sendRequest(
+            commitCapture.capture(),
+            ArgumentMatchers.<UnaryCallable<CommitRequest, CommitResponse>>any());
+
+    documentReference
+        .set(map("integer", FieldValue.maximum(1), "double", FieldValue.maximum(1.1)))
+        .get();
+
+    CommitRequest set =
+        commit(
+            set(Collections.emptyMap()),
+            transform(
+                "integer",
+                maximum(Value.newBuilder().setIntegerValue(1).build()),
+                "double",
+                maximum(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-firestore/src/test/java/com/google/cloud/firestore/LocalFirestoreHelper.java

@@ -501,6 +501,14 @@ public static FieldTransform increment(Value value) {
     return FieldTransform.newBuilder().setIncrement(value).build();
   }
 
+  public static FieldTransform minimum(Value value) {
+    return FieldTransform.newBuilder().setMinimum(value).build();
+  }
+
+  public static FieldTransform maximum(Value value) {
+    return FieldTransform.newBuilder().setMaximum(value).build();
+  }
+
   public static FieldTransform arrayUnion(Value... values) {
     return FieldTransform.newBuilder()
         .setAppendMissingElements(ArrayValue.newBuilder().addAllValues(Arrays.asList(values)))

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

@@ -1970,6 +1970,60 @@ public void floatIncrement() throws ExecutionException, InterruptedException {
     assertEquals(3.3, (Double) docSnap.get("sum"), DOUBLE_EPSILON);
   }
 
+  @Test
+  public void integerMinimum() throws ExecutionException, InterruptedException {
+    DocumentReference docRef = randomColl.document();
+    docRef.set(Collections.singletonMap("min", 2L)).get();
+    docRef.update("min", FieldValue.minimum(1)).get();
+    DocumentSnapshot docSnap = docRef.get().get();
+    assertEquals(1L, docSnap.get("min"));
+  }
+
+  @Test
+  public void floatMinimum() throws ExecutionException, InterruptedException {
+    DocumentReference docRef = randomColl.document();
+    docRef.set(Collections.singletonMap("min", 2.2)).get();
+    docRef.update("min", FieldValue.minimum(1.1)).get();
+    DocumentSnapshot docSnap = docRef.get().get();
+    assertEquals(1.1, (Double) docSnap.get("min"), DOUBLE_EPSILON);
+  }
+
+  @Test
+  public void minimumAgainstNonNumeric() throws ExecutionException, InterruptedException {
+    DocumentReference docRef = randomColl.document();
+    docRef.set(Collections.singletonMap("min", "any string")).get();
+    docRef.update("min", FieldValue.minimum(1)).get();
+    DocumentSnapshot docSnap = docRef.get().get();
+    assertEquals(1L, docSnap.get("min"));
+  }
+
+  @Test
+  public void integerMaximum() throws ExecutionException, InterruptedException {
+    DocumentReference docRef = randomColl.document();
+    docRef.set(Collections.singletonMap("max", 1L)).get();
+    docRef.update("max", FieldValue.maximum(2)).get();
+    DocumentSnapshot docSnap = docRef.get().get();
+    assertEquals(2L, docSnap.get("max"));
+  }
+
+  @Test
+  public void floatMaximum() throws ExecutionException, InterruptedException {
+    DocumentReference docRef = randomColl.document();
+    docRef.set(Collections.singletonMap("max", 1.1)).get();
+    docRef.update("max", FieldValue.maximum(2.2)).get();
+    DocumentSnapshot docSnap = docRef.get().get();
+    assertEquals(2.2, (Double) docSnap.get("max"), DOUBLE_EPSILON);
+  }
+
+  @Test
+  public void maximumAgainstNonNumeric() throws ExecutionException, InterruptedException {
+    DocumentReference docRef = randomColl.document();
+    docRef.set(Collections.singletonMap("max", "any string")).get();
+    docRef.update("max", FieldValue.maximum(2)).get();
+    DocumentSnapshot docSnap = docRef.get().get();
+    assertEquals(2L, docSnap.get("max"));
+  }
+
   @Test
   public void getAllWithObserver() throws Exception {
     DocumentReference ref1 = randomColl.document("doc1");