I have the following interface in a typescript file. export interface TempContext { FriendlyName?: boolean; hList: SelectFilterListItem[]; } SelectFilterListItem is an interface in another file export interface SelectFilterListItem { name: string; value: any; } I then want to use this in a function in the same file filterDef: new SelectFilterDef({ filterList: (context: TempContext) => context.hList, }), I get the following error Type '(context: TempContext) => SelectFilterListItem[]' is missing the following properties from type 'SelectFilterListItem[]': pop, push, concat, join, and 25 more. Continue reading...