Give me an ISO 3166-1 alpha-2 country code and I'll tell you if it's a member of the European Union.

Example Code

var isEuMember = require("is-eu-member").isEuMember,
getEuMembers = require("is-eu-member").getEuMembers;
console.log(getEuMembers());
console.log(isEuMember("CH")); // false
console.log(isEuMember("DE")); // true