fix(sorting): Respect sorting direction set to none when set through sortingExpressions

projects/igniteui-angular/src/lib/data-operations/sorting-strategy.spec.ts

@@ -24,34 +24,46 @@ describe('Unit testing SortingStrategy', () => {
                 strategy: DefaultSortingStrategy.instance()
             }]);
         expect(dataGenerator.getValuesForColumn(res, 'number'))
-                    .toEqual([4, 2, 0, 3, 1]);
+            .toEqual([4, 2, 0, 3, 1]);
     });
     it('tests `compareObjects`', () => {
         const strategy = DefaultSortingStrategy.instance();
         expect(strategy.compareValues(1, 0) === 1 &&
-                strategy.compareValues(true, false) === 1 &&
-                strategy.compareValues('bc', 'adfc') === 1)
+            strategy.compareValues(true, false) === 1 &&
+            strategy.compareValues('bc', 'adfc') === 1)
             .toBeTruthy('compare first argument greater than second');
         expect(strategy.compareValues(1, 2) === -1 &&
-                strategy.compareValues('a', 'b') === -1 &&
-                strategy.compareValues(false, true) === -1)
+            strategy.compareValues('a', 'b') === -1 &&
+            strategy.compareValues(false, true) === -1)
             .toBeTruthy('compare 0, 1');
         expect(strategy.compareValues(0, 0) === 0 &&
-                strategy.compareValues(true, true) === 0 &&
-                strategy.compareValues('test', 'test') === 0
-                )
+            strategy.compareValues(true, true) === 0 &&
+            strategy.compareValues('test', 'test') === 0
+        )
             .toBeTruthy('Comare equal variables');
     });
     it('tests default settings', () => {
         (data[4] as { string: string }).string = 'ROW';
         const res = sorting.sort(data, [{
-                dir: SortingDirection.Asc,
-                fieldName: 'string',
-                ignoreCase: true,
-                strategy: DefaultSortingStrategy.instance()
-            }]);
+            dir: SortingDirection.Asc,
+            fieldName: 'string',
+            ignoreCase: true,
+            strategy: DefaultSortingStrategy.instance()
+        }]);
         expect(dataGenerator.getValuesForColumn(res, 'number'))
-                    .toEqual([4, 0, 1, 2, 3]);
+            .toEqual([4, 0, 1, 2, 3]);
+    });
+
+    it('should not sort when sorting direction is None', () => {
+        const unsortedData = [{ number: 3 }, { number: 1 }, { number: 4 }, { number: 0 }, { number: 2 }];
+        const res = sorting.sort(unsortedData, [{
+            dir: SortingDirection.None,
+            fieldName: 'number',
+            ignoreCase: false,
+            strategy: DefaultSortingStrategy.instance()
+        }]);
+        expect(res.map(d => d.number))
+            .toEqual([3, 1, 4, 0, 2]);
     });
 
 });

projects/igniteui-angular/src/lib/grids/common/strategy.ts

@@ -5,7 +5,7 @@ import { IGroupingState } from '../../data-operations/groupby-state.interface';
 import { IGroupingExpression } from '../../data-operations/grouping-expression.interface';
 import { IGroupByResult } from '../../data-operations/grouping-result.interface';
 import { getHierarchy, isHierarchyMatch } from '../../data-operations/operations';
-import { DefaultSortingStrategy, ISortingExpression } from '../../data-operations/sorting-strategy';
+import { DefaultSortingStrategy, ISortingExpression, SortingDirection } from '../../data-operations/sorting-strategy';
 import { GridType } from './grid.interface';
 
 const DATE_TYPE = 'date';
@@ -141,6 +141,9 @@ export class IgxSorting implements IGridSortingStrategy {
     private prepareExpressions(expressions: ISortingExpression[], grid: GridType): IGridInternalSortingExpression[] {
         const multipleSortingExpressions: IGridInternalSortingExpression[] = [];
         for (const expr of expressions) {
+            if (expr.dir === SortingDirection.None) {
+                continue;
+            }
             if (!expr.strategy) {
                 expr.strategy = DefaultSortingStrategy.instance();
             }