Geojson validation does not throw erros on duplicate members

geojson-validation.ts

// run with ts-node and there will be no errors.
import { check } from "@placemarkio/check-geojson";
const geojsonHint = require("@mapbox/geojsonhint");

const testPolygon = {
    type: "Polygon",
    coordinates: [
        [
            [2, 1],
            [2, 1],
            [1, 2],
            [1, 2],
            [0, 0],
            [0, 0],
            [2, 1],
            [2, 1],
        ],
    ],
};
try {
    const parseValue = check(JSON.stringify(testPolygon));
    console.log("parseValue:", parseValue);
} catch (e) {
    /// e.issues
    console.error(e);
}

const errors = geojsonHint.hint(JSON.stringify(testPolygon), {
    noDuplicateMembers: true,
});
console.log("errors:", errors);