dupes-of-hazard/dist/index.js

Get a set of duplicates from an array.

"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.getDupes = void 0;
const json_stable_stringify_1 = __importDefault(require("json-stable-stringify"));
/**
 * Get a list of duplicate values from an array.
 */
function getDupes(arr) {
    const counts = new Map();
    const dupes = new Set();
    for (const item of arr) {
        const stringifiedItem = (0, json_stable_stringify_1.default)(item);
        const currentCount = counts.get(stringifiedItem);
        const newCount = currentCount ? currentCount + 1 : 1;
        counts.set(stringifiedItem, newCount);
        if (newCount === 2) {
            dupes.add(item);
        }
    }
    return dupes;
}
exports.getDupes = getDupes;