expands a string template with random values from arrays

generate.js

function generate(data) {
    function oneOf(ary) { return ary[Math.floor(Math.random() * ary.length)] }
    return data.template.replace(/@(\w+)/g, function (_, m) { return oneOf(data[m]) })
}

console.log(generate({
    template: "@descriptor @type who @focus",
    descriptor: ["appealing","brash","clever"],
    type: ["vector","paradox","spinner"],
    focus: ["looks for trouble","operates under cover","solves mysteries"]
}))