doNotWidenAtObjectLiteralPropertyAssignment.ts(10,60): error TS2322: Type 'null' is not assignable to type 'IIntervalTreeNode[] | undefined'.


==== doNotWidenAtObjectLiteralPropertyAssignment.ts (1 errors) ====
    interface ITestEventInterval {
        begin: number;
    }
    
    interface IIntervalTreeNode {
        interval: ITestEventInterval;
        children?: IIntervalTreeNode[];
    }
    
    var test: IIntervalTreeNode[] = [{ interval: { begin: 0 }, children: null }]; // was error here because best common type is {}
                                                               ~~~~~~~~
!!! error TS2322: Type 'null' is not assignable to type 'IIntervalTreeNode[] | undefined'.
!!! related TS6500 doNotWidenAtObjectLiteralPropertyAssignment.ts:7:5: The expected type comes from property 'children' which is declared here on type 'IIntervalTreeNode'
    