feat(QueryList): support index in callbacks

Closes #9278

modules/@angular/core/src/linker/query_list.ts

@@ -40,22 +40,24 @@ export class QueryList<T> {
   /**
    * returns a new array with the passed in function applied to each element.
    */
-  map<U>(fn: (item: T) => U): U[] { return this._results.map(fn); }
+  map<U>(fn: (item: T, index?: number) => U): U[] { return this._results.map(fn); }
 
   /**
    * returns a filtered array.
    */
-  filter(fn: (item: T) => boolean): T[] { return this._results.filter(fn); }
+  filter(fn: (item: T, index?: number) => boolean): T[] { return this._results.filter(fn); }
 
   /**
    * returns a reduced value.
    */
-  reduce<U>(fn: (acc: U, item: T) => U, init: U): U { return this._results.reduce(fn, init); }
+  reduce<U>(fn: (acc: U, item: T, index?: number) => U, init: U): U {
+    return this._results.reduce(fn, init);
+  }
 
   /**
    * executes function for each element in a query.
    */
-  forEach(fn: (item: T) => void): void { this._results.forEach(fn); }
+  forEach(fn: (item: T, index?: number) => void): void { this._results.forEach(fn); }
 
   /**
    * converts QueryList into an array

modules/@angular/core/test/linker/query_list_spec.ts

@@ -40,6 +40,11 @@ export function main() {
       expect(queryList.map((x) => x)).toEqual(['one', 'two']);
     });
 
+    it('should support map with index', () => {
+      queryList.reset(['one', 'two']);
+      expect(queryList.map((x, i) => `${x}_${i}`)).toEqual(['one_0', 'two_1']);
+    });
+
     it('should support forEach', () => {
       queryList.reset(['one', 'two']);
       let join = '';
@@ -47,25 +52,40 @@ export function main() {
       expect(join).toEqual('onetwo');
     });
 
+    it('should support forEach with index', () => {
+      queryList.reset(['one', 'two']);
+      let join = '';
+      queryList.forEach((x, i) => join = join + x + i);
+      expect(join).toEqual('one0two1');
+    });
+
     if (!IS_DART) {
       it('should support filter', () => {
         queryList.reset(['one', 'two']);
-        expect((<_JsQueryList>queryList).filter((x: any /** TODO #9100 */) => x == 'one')).toEqual([
-          'one'
-        ]);
+        expect((<_JsQueryList>queryList).filter((x: string) => x == 'one')).toEqual(['one']);
+      });
+
+      it('should support filter with index', () => {
+        queryList.reset(['one', 'two']);
+        expect((<_JsQueryList>queryList).filter((x: string, i: number) => i == 0)).toEqual(['one']);
       });
 
       it('should support reduce', () => {
         queryList.reset(['one', 'two']);
-        expect((<_JsQueryList>queryList)
-                   .reduce((a: any /** TODO #9100 */, x: any /** TODO #9100 */) => a + x, 'start:'))
+        expect((<_JsQueryList>queryList).reduce((a: string, x: string) => a + x, 'start:'))
             .toEqual('start:onetwo');
       });
 
+      it('should support reduce with index', () => {
+        queryList.reset(['one', 'two']);
+        expect((<_JsQueryList>queryList)
+                   .reduce((a: string, x: string, i: number) => a + x + i, 'start:'))
+            .toEqual('start:one0two1');
+      });
+
       it('should support toArray', () => {
         queryList.reset(['one', 'two']);
-        expect((<_JsQueryList>queryList)
-                   .reduce((a: any /** TODO #9100 */, x: any /** TODO #9100 */) => a + x, 'start:'))
+        expect((<_JsQueryList>queryList).reduce((a: string, x: string) => a + x, 'start:'))
             .toEqual('start:onetwo');
       });
 

tools/public_api_guard/public_api_spec.ts

@@ -414,14 +414,14 @@ const CORE = [
   'ProviderBuilder.toValue(value:any):Provider',
   'QueryList.changes:Observable<any>',
   'QueryList.dirty:any',
-  'QueryList.filter(fn:(item: T) => boolean):T[]',
+  'QueryList.filter(fn:(item: T, index?: number) => boolean):T[]',
   'QueryList.first:T',
-  'QueryList.forEach(fn:(item: T) => void):void',
+  'QueryList.forEach(fn:(item: T, index?: number) => void):void',
   'QueryList.last:T',
   'QueryList.length:number',
-  'QueryList.map(fn:(item: T) => U):U[]',
+  'QueryList.map(fn:(item: T, index?: number) => U):U[]',
   'QueryList.notifyOnChanges():void',
-  'QueryList.reduce(fn:(acc: U, item: T) => U, init:U):U',
+  'QueryList.reduce(fn:(acc: U, item: T, index?: number) => U, init:U):U',
   'QueryList.reset(res:Array<T|any[]>):void',
   'QueryList.setDirty():any',
   'QueryList.toArray():T[]',