Mila/count add api interface (#6499)

common/api-review/firestore.api.md

@@ -17,6 +17,30 @@ export type AddPrefixToKeys<Prefix extends string, T extends Record<string, unkn
     [K in keyof T & string as `${Prefix}.${K}`]+?: T[K];
 };
 
+// @public (undocumented)
+export class AggregateQuery<T = DocumentData> {
+    // (undocumented)
+    readonly query: Query<T>;
+    // (undocumented)
+    readonly type = "AggregateQuery";
+}
+
+// @public (undocumented)
+export function aggregateQueryEqual(left: AggregateQuery, right: AggregateQuery): boolean;
+
+// @public (undocumented)
+export class AggregateQuerySnapshot {
+    // (undocumented)
+    getCount(): number | null;
+    // (undocumented)
+    readonly query: AggregateQuery;
+    // (undocumented)
+    readonly type = "AggregateQuerySnapshot";
+}
+
+// @public (undocumented)
+export function aggregateQuerySnapshotEqual(left: AggregateQuerySnapshot, right: AggregateQuerySnapshot): boolean;
+
 // @public
 export function arrayRemove(...elements: unknown[]): FieldValue;
 
@@ -69,6 +93,9 @@ export function connectFirestoreEmulator(firestore: Firestore, host: string, por
     mockUserToken?: EmulatorMockTokenOptions | string;
 }): void;
 
+// @public (undocumented)
+export function countQuery(query: Query): AggregateQuery;
+
 // @public
 export function deleteDoc(reference: DocumentReference<unknown>): Promise<void>;
 
@@ -209,6 +236,9 @@ export class GeoPoint {
     };
 }
 
+// @public (undocumented)
+export function getAggregateFromServerDirect(query: AggregateQuery): Promise<AggregateQuerySnapshot>;
+
 // @public
 export function getDoc<T>(reference: DocumentReference<T>): Promise<DocumentSnapshot<T>>;
 

packages/firestore/src/api.ts

@@ -15,6 +15,15 @@
  * limitations under the License.
  */
 
+export {
+  AggregateQuery,
+  AggregateQuerySnapshot,
+  aggregateQueryEqual,
+  aggregateQuerySnapshotEqual,
+  countQuery,
+  getAggregateFromServerDirect
+} from './api/aggregate';
+
 export { FieldPath, documentId } from './api/field_path';
 
 export {

packages/firestore/src/api/aggregate.ts

@@ -0,0 +1,25 @@
+/**
+ * @license
+ * Copyright 2022 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+export {
+  AggregateQuery,
+  AggregateQuerySnapshot,
+  aggregateQueryEqual,
+  aggregateQuerySnapshotEqual,
+  countQuery,
+  getAggregateFromServerDirect
+} from '../lite-api/aggregate';

packages/firestore/src/lite-api/aggregate.ts

@@ -0,0 +1,69 @@
+/**
+ * @license
+ * Copyright 2022 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { DocumentData, Query, queryEqual } from './reference';
+
+export class AggregateQuery<T = DocumentData> {
+  readonly type = 'AggregateQuery';
+  readonly query: Query<T>;
+
+  /** @hideconstructor */
+  constructor(query: Query<T>) {
+    this.query = query;
+  }
+}
+
+export class AggregateQuerySnapshot {
+  readonly type = 'AggregateQuerySnapshot';
+  readonly query: AggregateQuery;
+
+  /** @hideconstructor */
+  constructor(query: AggregateQuery, readonly _count: number) {
+    this.query = query;
+  }
+
+  getCount(): number | null {
+    return this._count;
+  }
+}
+
+export function countQuery(query: Query): AggregateQuery {
+  return new AggregateQuery(query);
+}
+
+export function getAggregateFromServerDirect(
+  query: AggregateQuery
+): Promise<AggregateQuerySnapshot> {
+  return Promise.resolve(new AggregateQuerySnapshot(query, 42));
+}
+
+export function aggregateQueryEqual(
+  left: AggregateQuery,
+  right: AggregateQuery
+): boolean {
+  return queryEqual(left.query, right.query);
+}
+
+export function aggregateQuerySnapshotEqual(
+  left: AggregateQuerySnapshot,
+  right: AggregateQuerySnapshot
+): boolean {
+  return (
+    aggregateQueryEqual(left.query, right.query) &&
+    left.getCount() === right.getCount()
+  );
+}