fix(esf): add empty filter to filtering event

Author: igdmdimitrov

projects/igniteui-angular/src/lib/grids/filtering/grid-filtering.service.ts

@@ -277,9 +277,10 @@ export class IgxFilteringService implements OnDestroy {
             }
         }
 
+        const emptyFilter = new FilteringExpressionsTree(null, field);
         const onFilteringEventArgs: IFilteringEventArgs = {
             owner: this.grid,
-            filteringExpressions: null,
+            filteringExpressions: emptyFilter,
             cancel: false };
 
         this.grid.filtering.emit(onFilteringEventArgs);
@@ -292,7 +293,6 @@ export class IgxFilteringService implements OnDestroy {
         this.clear_filter(field);
 
         // Wait for the change detection to update filtered data through the pipes and then emit the event.
-        const emptyFilter = new FilteringExpressionsTree(null, field);
         requestAnimationFrame(() => this.grid.filteringDone.emit(emptyFilter));
 
         if (field) {

projects/igniteui-angular/src/lib/grids/grid/grid-filtering-ui.spec.ts

@@ -485,9 +485,9 @@ describe('IgxGrid - Filtering Row UI actions #grid', () => {
             GridFunctions.clickFilterCellChip(fix, columnName);
             GridFunctions.resetFilterRow(fix);
 
-            expect(grid.filtering.emit).toHaveBeenCalledWith({ owner: grid, cancel: false, filteringExpressions: null });
-            expect(grid.filtering.emit).toHaveBeenCalledTimes(2);
             const emptyFilter = new FilteringExpressionsTree(null, columnName);
+            expect(grid.filtering.emit).toHaveBeenCalledWith({ owner: grid, cancel: false, filteringExpressions: emptyFilter });
+            expect(grid.filtering.emit).toHaveBeenCalledTimes(2);
             expect(grid.filteringDone.emit).toHaveBeenCalledWith(emptyFilter);
             expect(grid.filteringDone.emit).toHaveBeenCalledTimes(2);
 
@@ -513,9 +513,9 @@ describe('IgxGrid - Filtering Row UI actions #grid', () => {
             tick(100);
             fix.detectChanges();
 
-            const args = { owner: grid, cancel: false, filteringExpressions: null };
-            expect(grid.filtering.emit).toHaveBeenCalledWith(args);
             const emptyFilter = new FilteringExpressionsTree(null, columnName);
+            const args = { owner: grid, cancel: false, filteringExpressions: emptyFilter };
+            expect(grid.filtering.emit).toHaveBeenCalledWith(args);
             expect(grid.filteringDone.emit).toHaveBeenCalledWith(emptyFilter);
         }));
 
@@ -852,10 +852,10 @@ describe('IgxGrid - Filtering Row UI actions #grid', () => {
 
             expect(grid.rowList.length).toEqual(8);
 
-            args.filteringExpressions = null;
+            const emptyFilter = new FilteringExpressionsTree(null, columnName);
+            args.filteringExpressions = emptyFilter;
             expect(grid.filtering.emit).toHaveBeenCalledWith(args);
             expect(grid.filtering.emit).toHaveBeenCalledTimes(2);
-            const emptyFilter = new FilteringExpressionsTree(null, columnName);
             expect(grid.filteringDone.emit).toHaveBeenCalledWith(emptyFilter);
             expect(grid.filteringDone.emit).toHaveBeenCalledTimes(2);
         }));