JSFiddle - React, Tailwind, and code Playground

HTML

Look in the console.

TypeScript

const roleStrings = {
    USER: "",
    PRESENTER: "",
    ORGANIZER: "",
    ADMIN: ""
};

type Role = keyof typeof roleStrings;

const isRole = (s: string): s is Role => {
    return roleStrings.hasOwnProperty(s);
};

const rawToRoleArray = (rawArray: string[]): Role[] => {
    return rawArray.map(s => {
        if (!isRole(s)) {
            throw new Error("Invalid Role: " + s);
        }
        return <Role>s;
    });
};

// Valid
const realRoleArray: Role[] = rawToRoleArray(["ADMIN", "USER"]); 
console.log(realRoleArray);
// Invalid
const realRoleArray2: Role[] = rawToRoleArray(["ADMIN", "FOO"]); 
console.log(realRoleArray2);