refactor: format and lint codebase (#971)

app/assets/javascripts/Hooks/useCloseOnBlur.ts

@@ -0,0 +1,24 @@
+import { StateUpdater, useCallback, useState } from 'preact/hooks'
+
+/**
+ * @returns a callback that will close a dropdown if none of its children has
+ * focus. Use the returned function as the onBlur callback of children that need to be
+ * monitored.
+ */
+export function useCloseOnBlur(
+  container: { current?: HTMLDivElement | null },
+  setOpen: (open: boolean) => void,
+): [(event: { relatedTarget: EventTarget | null }) => void, StateUpdater<boolean>] {
+  const [locked, setLocked] = useState(false)
+  return [
+    useCallback(
+      function onBlur(event: { relatedTarget: EventTarget | null }) {
+        if (!locked && !container.current?.contains(event.relatedTarget as Node)) {
+          setOpen(false)
+        }
+      },
+      [container, setOpen, locked],
+    ),
+    setLocked,
+  ]
+}