test(TreeGrid): Adding a test for order of records after hierarchizing

Author: gedinakova

projects/igniteui-angular/src/lib/grids/tree-grid/tree-grid-integration.spec.ts

@@ -198,6 +198,74 @@ describe('IgxTreeGrid - Integration #tGrid', () => {
             treeGrid = fix.componentInstance.treeGrid;
         });
 
+        it('should preserve the order of records on inner levels', () => {
+            fix.componentInstance.sortByName = true;
+            fix.detectChanges();
+            treeGrid.columns[0].hidden = true;
+            treeGrid.columns[1].hidden = true;
+            fix.detectChanges();
+
+            const expectedFlatData = [
+                {
+                    "ID": 1,
+                    "ParentID": -1,
+                    "Name": "Casey Houston",
+                    "JobTitle": "Vice President",
+                    "Age": 32
+                },
+                {
+                    "ID": 2,
+                    "ParentID": 1,
+                    "Name": "Gilberto Todd",
+                    "JobTitle": "Director",
+                    "Age": 41
+                },
+                {
+                    "ID": 7,
+                    "ParentID": 2,
+                    "Name": "Debra Morton",
+                    "JobTitle": "Associate Software Developer",
+                    "Age": 35
+                },
+                {
+                    "ID": 3,
+                    "ParentID": 2,
+                    "Name": "Tanya Bennett",
+                    "JobTitle": "Director",
+                    "Age": 29
+                },
+                {
+                    "ID": 4,
+                    "ParentID": 1,
+                    "Name": "Jack Simon",
+                    "JobTitle": "Software Developer",
+                    "Age": 33
+                },
+                {
+                    "ID": 10,
+                    "ParentID": -1,
+                    "Name": "Eduardo Ramirez",
+                    "JobTitle": "Manager",
+                    "Age": 53
+                },
+                {
+                    "ID": 9,
+                    "ParentID": 10,
+                    "Name": "Leslie Hansen",
+                    "JobTitle": "Associate Software Developer",
+                    "Age": 44
+                },
+                {
+                    "ID": 6,
+                    "ParentID": -1,
+                    "Name": "Erma Walsh",
+                    "JobTitle": "CEO",
+                    "Age": 52
+                },
+            ]
+            expect(treeGrid.flatData).toEqual(expectedFlatData);
+        });
+
         it('should transform a non-tree column into a tree column when pinning it', () => {
             TreeGridFunctions.verifyTreeColumn(fix, 'ID', 5);
 

projects/igniteui-angular/src/lib/test-utils/tree-grid-components.spec.ts

@@ -159,10 +159,17 @@ export class IgxTreeGridWithNoScrollsComponent {
     `,
     imports: [IgxTreeGridComponent, IgxColumnComponent, IgxPaginatorComponent]
 })
-export class IgxTreeGridPrimaryForeignKeyComponent {
+export class IgxTreeGridPrimaryForeignKeyComponent implements OnInit {
     @ViewChild(IgxTreeGridComponent, { static: true }) public treeGrid: IgxTreeGridComponent;
-    public data = SampleTestData.employeePrimaryForeignKeyTreeData();
+    public data = [];
     public paging = false;
+    public sortByName = false;
+
+    public ngOnInit(): void {
+        this.data = !this.sortByName
+                        ? SampleTestData.employeePrimaryForeignKeyTreeData()
+                        : SampleTestData.employeePrimaryForeignKeyTreeData().sort((a, b) => a.Name.localeCompare(b.Name));
+    }
 }
 
 @Component({