chore: add npm + vite for progressive enhancement

src/utils/polyfills.js

@@ -0,0 +1,41 @@
+"use strict";
+
+// replaceAll
+if (String.prototype.replaceAll === undefined) {
+  String.prototype.replaceAll = function (str, newStr) {
+    if (Object.prototype.toString.call(str).toLowerCase() === "[object regexp]") return this.replace(str, newStr);
+    return this.replace(new RegExp(str, "g"), newStr);
+  };
+}
+
+// flat
+if (Array.prototype.flat === undefined) {
+  Array.prototype.flat = function () {
+    return this.reduce((acc, val) => (Array.isArray(val) ? acc.concat(val.flat()) : acc.concat(val)), []);
+  };
+}
+
+// at
+if (Array.prototype.at === undefined) {
+  Array.prototype.at = function (index) {
+    if (index < 0) index += this.length;
+    if (index < 0 || index >= this.length) return undefined;
+    return this[index];
+  };
+}
+
+// readable stream iterator: https://bugs.chromium.org/p/chromium/issues/detail?id=929585#c10
+if (ReadableStream.prototype[Symbol.asyncIterator] === undefined) {
+  ReadableStream.prototype[Symbol.asyncIterator] = async function* () {
+    const reader = this.getReader();
+    try {
+      while (true) {
+        const {done, value} = await reader.read();
+        if (done) return;
+        yield value;
+      }
+    } finally {
+      reader.releaseLock();
+    }
+  };
+}