Fixing nullability for Query.on/Query.off

Author: schmidt-sebastian

packages/database-types/index.d.ts

@@ -68,20 +68,20 @@ export interface Query {
   limitToLast(limit: number): Query;
   off(
     eventType?: EventType,
-    callback?: (a: DataSnapshot, b?: string | null) => any,
-    context?: Object | null
-  ): any;
+    callback?: (a: DataSnapshot, b?: string) => any,
+    context?: Object
+  ): void;
   on(
     eventType: EventType,
-    callback: (a: DataSnapshot | null, b?: string) => any,
-    cancelCallbackOrContext?: Object | null,
-    context?: Object | null
-  ): (a: DataSnapshot | null, b?: string) => any;
+    callback: (a: DataSnapshot, b?: string) => any,
+    cancelCallbackOrContext?: ((a: Error) => any) | Object,
+    context?: Object
+  ): (a: DataSnapshot, b?: string) => any;
   once(
     eventType: EventType,
     successCallback?: (a: DataSnapshot, b?: string) => any,
-    failureCallbackOrContext?: Object | null,
-    context?: Object | null
+    cancelCallbackOrContext?: ((a: Error) => void) | Object,
+    context?: Object
   ): Promise<DataSnapshot>;
   orderByChild(path: string): Query;
   orderByKey(): Query;

packages/database/src/api/Query.ts

@@ -263,7 +263,11 @@ export class Query {
    * @param {(function(!DataSnapshot, ?string=))=} callback
    * @param {Object=} context
    */
-  off(eventType?: string, callback?: SnapshotCallback, context?: Object) {
+  off(
+    eventType?: string,
+    callback?: SnapshotCallback,
+    context?: Object
+  ): void {
     validateArgCount('Query.off', 0, 3, arguments.length);
     validateEventType('Query.off', 1, eventType, true);
     validateCallback('Query.off', 2, callback, true);

packages/database/src/core/view/Event.ts

@@ -65,7 +65,7 @@ export class DataEvent implements Event {
       | ' child_removed',
     public eventRegistration: EventRegistration,
     public snapshot: DataSnapshot,
-    public prevName?: string | null
+    public prevName?: string
   ) {}
 
   /**