Introduced new interface to represent iterated elements

Author: maneesht

common/api-review/database.api.md

@@ -33,9 +33,7 @@ export class DataSnapshot {
     child(path: string): DataSnapshot;
     exists(): boolean;
     exportVal(): any;
-    forEach(action: (child: DataSnapshot & {
-        key: string;
-    }) => boolean | void): boolean;
+    forEach(action: (child: IteratedDataSnapshot) => boolean | void): boolean;
     hasChild(path: string): boolean;
     hasChildren(): boolean;
     get key(): string | null;
@@ -87,6 +85,12 @@ export function goOnline(db: Database): void;
 // @public
 export function increment(delta: number): object;
 
+// @public
+export interface IteratedDataSnapshot extends DataSnapshot {
+    // (undocumented)
+    key: string;
+}
+
 // @public
 export function limitToFirst(limit: number): QueryConstraint;
 

packages/database-compat/src/api/Reference.ts

@@ -156,6 +156,8 @@ export class DataSnapshot implements Compat<ModularDataSnapshot> {
     return this._delegate.priority;
   }
 
+  
+
   /**
    * Iterates through child nodes and calls the specified action for each one.
    *
@@ -165,7 +167,7 @@ export class DataSnapshot implements Compat<ModularDataSnapshot> {
    * one of the child nodes.
    */
   forEach(
-    action: (snapshot: DataSnapshot & { key: string }) => boolean | void
+    action: (snapshot: IteratedDataSnapshot) => boolean | void
   ): boolean {
     validateArgCount('DataSnapshot.forEach', 1, 1, arguments.length);
     validateCallback('DataSnapshot.forEach', 'action', action, false);
@@ -210,6 +212,10 @@ export class DataSnapshot implements Compat<ModularDataSnapshot> {
   }
 }
 
+export interface IteratedDataSnapshot extends DataSnapshot {
+  key: string;
+}
+
 export interface SnapshotCallback {
   (dataSnapshot: DataSnapshot, previousChildName?: string | null): unknown;
 }

packages/database-types/index.d.ts

@@ -18,12 +18,19 @@
 import { FirebaseApp } from '@firebase/app-types';
 import { EmulatorMockTokenOptions } from '@firebase/util';
 
+/**
+ * Represents a child snapshot of an iterated `Reference`. The key will never be undefined.
+ */
+export interface IteratedDataSnapshot extends DataSnapshot {
+  key: string;
+}
+
 export interface DataSnapshot {
   child(path: string): DataSnapshot;
   exists(): boolean;
   exportVal(): any;
   forEach(
-    action: (a: DataSnapshot & { key: string }) => boolean | void
+    action: (a: IteratedDataSnapshot) => boolean | void
   ): boolean;
   getPriority(): string | number | null;
   hasChild(path: string): boolean;

packages/database/src/api.standalone.ts

@@ -37,6 +37,7 @@ export { OnDisconnect } from './api/OnDisconnect';
 export {
   DataSnapshot,
   EventType,
+  IteratedDataSnapshot,
   QueryConstraint,
   QueryConstraintType,
   endAt,

packages/database/src/api/Reference_impl.ts

@@ -376,7 +376,7 @@ export class DataSnapshot {
   }
 
   /**
-   * Enumerates the top-level children in the `DataSnapshot`.
+   * Enumerates the top-level children in the `IteratorDataSnapshot`.
    *
    * Because of the way JavaScript objects work, the ordering of data in the
    * JavaScript object returned by `val()` is not guaranteed to match the
@@ -394,7 +394,7 @@ export class DataSnapshot {
    * true.
    */
   forEach(
-    action: (child: DataSnapshot & { key: string }) => boolean | void
+    action: (child: IteratedDataSnapshot) => boolean | void
   ): boolean {
     if (this._node.isLeafNode()) {
       return false;
@@ -465,6 +465,13 @@ export class DataSnapshot {
   }
 }
 
+/**
+ * Represents a child snapshot of an iterated `Reference`. The key will never be undefined.
+ */
+export interface IteratedDataSnapshot extends DataSnapshot {
+  key: string;
+}
+
 /**
  *
  * Returns a `Reference` representing the location in the Database

packages/firebase/compat/index.d.ts

@@ -5820,7 +5820,7 @@ declare namespace firebase.database {
      */
     forEach(
       action: (
-        a: firebase.database.DataSnapshot & { key: string }
+        a: firebase.database.IteratorDataSnapshot
       ) => boolean | void
     ): boolean;
     /**