feat(auth): implement user authentication system

backend/node_modules/jest-watcher/build/lib/scroll.js

@@ -0,0 +1,31 @@
+'use strict';
+
+Object.defineProperty(exports, '__esModule', {
+  value: true
+});
+exports.default = scroll;
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+function scroll(size, {offset, max}) {
+  let start = 0;
+  let index = Math.min(offset, size);
+  const halfScreen = max / 2;
+  if (index <= halfScreen) {
+    start = 0;
+  } else {
+    if (size >= max) {
+      start = Math.min(index - halfScreen - 1, size - max);
+    }
+    index = Math.min(index - start, size);
+  }
+  return {
+    end: Math.min(size, start + max),
+    index,
+    start
+  };
+}