Test case to understand how to use typescript generics properly. needs noImplicitAny set

generic.ts

interface FilterOption {
	key: string | number;
	displayValue: string;
	predicate: <TEntity>(e: TEntity) => boolean;
}

interface Registration {
	id: number;
	name: string;
	date: string;
}

function foo(registrations: Registration[]):FilterOption[] {
	return registrations.map(r => ({
		key: r.id,
		displayValue: r.name,
		predicate: (r: Registration) => r.date.length <= 8
	}));
}

const registrations = [{
	id: 1,
	name: 'max',
	date: '2018212'
}, {
	id: 12,
	name: 'george',
	date: '20182110'
}, {
	id: 123,
	name: 'Sam',
	date: '201821201'
}, {
	id: 1234,
	name: 'froddo',
	date: '2018212'
	}];
const options = foo(registrations);
console.log(options);