add: unit and integration testing

app/node_modules/@ungap/structured-clone/esm/json.js

@@ -0,0 +1,21 @@
+/*! (c) Andrea Giammarchi - ISC */
+
+import {deserialize} from './deserialize.js';
+import {serialize} from './serialize.js';
+
+const {parse: $parse, stringify: $stringify} = JSON;
+const options = {json: true, lossy: true};
+
+/**
+ * Revive a previously stringified structured clone.
+ * @param {string} str previously stringified data as string.
+ * @returns {any} whatever was previously stringified as clone.
+ */
+export const parse = str => deserialize($parse(str));
+
+/**
+ * Represent a structured clone value as string.
+ * @param {any} any some clone-able value to stringify.
+ * @returns {string} the value stringified.
+ */
+export const stringify = any => $stringify(serialize(any, options));