1 files changed, 33 insertions, 0 deletions
diff --git a/packages/excalidraw/polyfill.ts b/packages/excalidraw/polyfill.ts
new file mode 100644
index 0000000..b8b080f
--- /dev/null
+++ b/packages/excalidraw/polyfill.ts
@@ -0,0 +1,33 @@
+const polyfill = () => {
+  if (!Array.prototype.at) {
+    // Taken from https://github.com/tc39/proposal-relative-indexing-method#polyfill so that it works in tests
+    /* eslint-disable */
+    Object.defineProperty(Array.prototype, "at", {
+      value: function (n: number) {
+        // ToInteger() abstract op
+        n = Math.trunc(n) || 0;
+        // Allow negative indexing from the end
+        if (n < 0) {
+          n += this.length;
+        }
+        // OOB access is guaranteed to return undefined
+        if (n < 0 || n >= this.length) {
+          return undefined;
+        }
+        // Otherwise, this is just normal property access
+        return this[n];
+      },
+      writable: true,
+      enumerable: false,
+      configurable: true,
+    });
+  }
+
+  if (!Element.prototype.replaceChildren) {
+    Element.prototype.replaceChildren = function (...nodes) {
+      this.innerHTML = "";
+      this.append(...nodes);
+    };
+  }
+};
+export default polyfill;