fix(grid): adding null as possible value for width and height #9980

Author: ChronosSF

projects/igniteui-angular/src/lib/grids/grid-base.directive.ts

@@ -1597,11 +1597,11 @@ export abstract class IgxGridBaseDirective extends DisplayDensityBase implements
     @WatchChanges()
     @HostBinding('style.height')
     @Input()
-    public get height() {
+    public get height(): string | null {
         return this._height;
     }
 
-    public set height(value: string) {
+    public set height(value: string | null) {
         if (this._height !== value) {
             this._height = value;
             this.nativeElement.style.height = value;
@@ -1627,11 +1627,11 @@ export abstract class IgxGridBaseDirective extends DisplayDensityBase implements
      */
     @WatchChanges()
     @Input()
-    public get width() {
+    public get width(): string | null {
         return this._width;
     }
 
-    public set width(value) {
+    public set width(value: string | null) {
         if (this._width !== value) {
             this._width = value;
             this.nativeElement.style.width = value;
@@ -2942,8 +2942,8 @@ export abstract class IgxGridBaseDirective extends DisplayDensityBase implements
     private rowListDiffer;
     private _hiddenColumnsText = '';
     private _pinnedColumnsText = '';
-    private _height = '100%';
-    private _width = '100%';
+    private _height: string | null = '100%';
+    private _width: string | null = '100%';
     private _rowHeight;
     private _horizontalForOfs: Array<IgxGridForOfDirective<any>> = [];
     private _multiRowLayoutRowSize = 1;