@extra-entries/key-of v1.1.1

Get first key of value in entries, like Array.indexOf().

const keyOf = require('@extra-entries/key-of');
// keyOf(<entries>, <search value>, [begin=0], [end])

keyOf(['flintstones', 'jetsons', 'jetsons'].entries(), 'jetsons');
// 1
keyOf(new Set(['ducktales', 'talespin']).entries(), 'ducktales');
// 'ducktales'
keyOf(Object.entries({dexter: 1996, samuraijack: 2001}), 2002);
// undefined