fix(filtering): fix condition changing when erasing the value #10596

Author: zhosti

projects/igniteui-angular/src/lib/grids/filtering/base/grid-filtering-row.component.ts

@@ -72,7 +72,12 @@ export class IgxGridFilteringRowComponent implements AfterViewInit, OnDestroy {
             this.expression.searchVal = null;
             const index = this.expressionsList.findIndex(item => item.expression === this.expression);
             if (index === 0 && this.expressionsList.length === 1) {
-                this.clearFiltering();
+                this.filteringService.clearFilter(this.column.field);
+                
+                if (this.expression.condition.isUnary) {
+                    this.resetExpression();
+                }
+
                 return;
             }
         } else {

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

@@ -2064,6 +2064,20 @@ describe('IgxGrid - Filtering Row UI actions #grid', () => {
             expect(grid.filteredData).toBeNull();
         }));
 
+        it('should not reset expression when input is cleared', fakeAsync(() => {
+            grid.filter('ProductName', 'I', IgxStringFilteringOperand.instance().condition('startsWith'));
+            fix.detectChanges();
+
+            GridFunctions.clickFilterCellChip(fix, 'ProductName');
+
+            grid.filteringRow.onClearClick();
+            tick(100);
+            fix.detectChanges();
+            console.log(grid.filteringRow.expression.condition.name);
+
+            expect(grid.filteringRow.expression.condition.name).toEqual('startsWith');
+        }));
+
         it('Should filter by cells formatted data when using FormattedValuesFilteringStrategy', fakeAsync(() => {
             const formattedStrategy = new FormattedValuesFilteringStrategy(['Downloads']);
             grid.filterStrategy = formattedStrategy;
@@ -6640,8 +6654,6 @@ const emitFilteringDoneOnInputClear = (fix, grid, filterVal, columnName, conditi
 
     GridFunctions.clickFilterCellChip(fix, columnName);
 
-    // spyOn(grid.filteringDone, 'emit');
-
     grid.filteringRow.onClearClick();
     tick(100);
     fix.detectChanges();