feat: Add sum method to AggregateQuerySnapshot

firestore/src/android/aggregate_query_android.h

@@ -33,7 +33,8 @@ class AggregateQueryInternal : public Wrapper {
   // Firestore Future manager.
   enum class AsyncFn {
     kGet = 0,
-    kCount,  // Must be the last enum value.
+    kCount,
+    kSum,  // Must be the last enum value.
   };
 
   static void Initialize(jni::Loader& loader);

firestore/src/android/aggregate_query_snapshot_android.h

@@ -34,6 +34,7 @@ class AggregateQuerySnapshotInternal : public Wrapper {
 
   AggregateQuery query() const;
   int64_t count() const;
+  double sum(const AggregateField& aggregate_field) const;
 
   std::size_t Hash() const;
 

firestore/src/common/aggregate_query_snapshot.cc

@@ -103,6 +103,11 @@ int64_t AggregateQuerySnapshot::count() const {
   return internal_->count();
 }
 
+double AggregateQuerySnapshot::sum(const AggregateField& aggregate_field) const {
+  if (!internal_) return 0;
+  return internal_->sum(aggregate_field);
+}
+
 bool operator==(const AggregateQuerySnapshot& lhs,
                 const AggregateQuerySnapshot& rhs) {
   return EqualityCompare(lhs.internal_, rhs.internal_);

firestore/src/include/firebase/firestore/aggregate_query_snapshot.h

@@ -108,6 +108,14 @@ class AggregateQuerySnapshot {
    */
   virtual int64_t count() const;
 
+  /**
+   * @brief Returns the sum of the specified field across all documents in the
+   * result set of the underlying query.
+   *
+   * @return The sum of the specified field across all documents.
+   */
+  virtual double sum(const AggregateField& aggregate_field) const;
+
   /**
    * @brief Returns true if this `AggregateQuerySnapshot` is valid, false if it
    * is not valid. An invalid `AggregateQuerySnapshot` could be the result of:

firestore/src/main/aggregate_query_main.h

@@ -50,6 +50,7 @@ class AggregateQueryInternal {
   enum class AsyncApis {
     kGet,
     kCount,
+    kSum,
   };
 
   friend class AggregateQuerySnapshotTest;

firestore/src/main/aggregate_query_snapshot_main.cc

@@ -24,9 +24,15 @@ namespace firebase {
 namespace firestore {
 
 AggregateQuerySnapshotInternal::AggregateQuerySnapshotInternal(
-    api::AggregateQuery&& aggregate_query, int64_t count_result)
+    api::AggregateQuery&& aggregate_query, int64_t count_result,
+    // TODO: Update with sum
+    // double sum_result,
+    )
     : aggregate_query_(std::move(aggregate_query)),
-      count_result_(count_result) {}
+      count_result_(count_result)
+      // TODO: Update with sum
+      // sum_result_(sum_result),
+      {}
 
 FirestoreInternal* AggregateQuerySnapshotInternal::firestore_internal() {
   return GetFirestoreInternal(&aggregate_query_.query());
@@ -43,10 +49,16 @@ AggregateQuery AggregateQuerySnapshotInternal::query() const {
 
 int64_t AggregateQuerySnapshotInternal::count() const { return count_result_; }
 
+double AggregateQuerySnapshotInternal::sum(const AggregateField& aggregate_field) const {
+  // TODO: implement
+}
+
 bool operator==(const AggregateQuerySnapshotInternal& lhs,
                 const AggregateQuerySnapshotInternal& rhs) {
   return lhs.aggregate_query_ == rhs.aggregate_query_ &&
          lhs.count_result_ == rhs.count_result_;
+         // TODO: Update with sum
+         // && lhs.sum_result == rhs.sum_result_;
 }
 
 }  // namespace firestore

firestore/src/main/aggregate_query_snapshot_main.h

@@ -35,15 +35,20 @@ class AggregateQuerySnapshotInternal {
  public:
   explicit AggregateQuerySnapshotInternal(api::AggregateQuery&& aggregate_query,
                                           int64_t count);
+                                          // TODO: Update with sum
+                                          // double sum);
 
   FirestoreInternal* firestore_internal();
   const FirestoreInternal* firestore_internal() const;
 
   AggregateQuery query() const;
   int64_t count() const;
+  double sum(const AggregateField& aggregate_field) const;
 
   std::size_t Hash() const {
     return util::Hash(aggregate_query_.query().Hash(), count_result_);
+    // TODO: Update with sum
+    // , sum_result_);
   }
 
   friend bool operator==(const AggregateQuerySnapshotInternal& lhs,
@@ -52,6 +57,7 @@ class AggregateQuerySnapshotInternal {
  private:
   api::AggregateQuery aggregate_query_;
   int64_t count_result_ = 0;
+  double sum_result_ = 0.0;
 };
 
 inline bool operator!=(const AggregateQuerySnapshotInternal& lhs,