chore: Move to Typescript (#2783)

This PR moves the entire project to Typescript. Due to the ~1000 ignores this will lead to a messy codebase for a while, but the churn is worth it – all of those ignore comments are places that were never type-safe previously.

closes #1282

app/hooks/useWindowScrollPosition.ts

@@ -0,0 +1,60 @@
+// Based on https://github.com/rehooks/window-scroll-position which is no longer
+// maintained.
+import { throttle } from "lodash";
+import { useState, useEffect } from "react";
+
+let supportsPassive = false;
+
+try {
+  const opts = Object.defineProperty({}, "passive", {
+    get: function () {
+      supportsPassive = true;
+    },
+  });
+  // @ts-expect-error ts-migrate(2769) FIXME: No overload matches this call.
+  window.addEventListener("testPassive", null, opts);
+  // @ts-expect-error ts-migrate(2769) FIXME: No overload matches this call.
+  window.removeEventListener("testPassive", null, opts);
+} catch (e) {
+  // No-op
+}
+
+const getPosition = () => ({
+  x: window.pageXOffset,
+  y: window.pageYOffset,
+});
+
+const defaultOptions = {
+  throttle: 100,
+};
+
+export default function useWindowScrollPosition(options: {
+  throttle: number;
+}): {
+  x: number;
+  y: number;
+} {
+  const opts = Object.assign({}, defaultOptions, options);
+  const [position, setPosition] = useState(getPosition());
+
+  useEffect(() => {
+    const handleScroll = throttle(() => {
+      setPosition(getPosition());
+    }, opts.throttle);
+    window.addEventListener(
+      "scroll",
+      handleScroll,
+      supportsPassive
+        ? {
+            passive: true,
+          }
+        : false
+    );
+    return () => {
+      handleScroll.cancel();
+      window.removeEventListener("scroll", handleScroll);
+    };
+  }, [opts.throttle]);
+
+  return position;
+}