Namespaces are defined in TypeScript with an object which may have properties.
Using export = indicates the object should be replaced with that value, which
doesn't make sense.
namespace NS {
export = function () {};
}Fix: Remove the namespace.
Remove the namespace and directly create the export:
function NS() {}Fix: Export a property.
Export it as a property of the namespace:
namespace NS {
export function fn() {}
}