Reload user settings when changed externally (#4097)

* Reload user settings when changed externally

* Fix to not use any

* Make sure listener doesn't already exist

* Fix up projects reloading

---------

Co-authored-by: Jonathan Tran <jonnytran@gmail.com>

src/hooks/useFileSystemWatcher.tsx

@@ -1,4 +1,5 @@
 import { isDesktop } from 'lib/isDesktop'
+import { reportRejection } from 'lib/trap'
 import { useEffect, useState, useRef } from 'react'
 
 type Path = string
@@ -11,13 +12,13 @@ type Path = string
 // watcher.addListener(() => { ... }).
 
 export const useFileSystemWatcher = (
-  callback: (path: Path) => void,
+  callback: (path: Path) => Promise<void>,
   dependencyArray: Path[]
 ): void => {
   // Track a ref to the callback. This is how we get the callback updated
   // across the NodeJS<->Browser boundary.
-  const callbackRef = useRef<{ fn: (path: Path) => void }>({
-    fn: (_path) => {},
+  const callbackRef = useRef<{ fn: (path: Path) => Promise<void> }>({
+    fn: async (_path) => {},
   })
 
   useEffect(() => {
@@ -35,7 +36,9 @@ export const useFileSystemWatcher = (
     if (!isDesktop()) return
 
     return () => {
-      window.electron.watchFileObliterate()
+      for (let path of dependencyArray) {
+        window.electron.watchFileOff(path)
+      }
     }
   }, [])
 
@@ -46,6 +49,9 @@ export const useFileSystemWatcher = (
     ]
   }
 
+  const hasDiff =
+    difference(dependencyArray, dependencyArrayTracked)[0].length !== 0
+
   // Removing 1 watcher at a time is only possible because in a filesystem,
   // a path is unique (there can never be two paths with the same name).
   // Otherwise we would have to obliterate() the whole list and reconstruct it.
@@ -53,6 +59,8 @@ export const useFileSystemWatcher = (
     // The hook is useless on web.
     if (!isDesktop()) return
 
+    if (!hasDiff) return
+
     const [pathsRemoved, pathsRemaining] = difference(
       dependencyArrayTracked,
       dependencyArray
@@ -62,10 +70,10 @@ export const useFileSystemWatcher = (
     }
     const [pathsAdded] = difference(dependencyArray, dependencyArrayTracked)
     for (let path of pathsAdded) {
-      window.electron.watchFileOn(path, (_eventType: string, path: Path) =>
-        callbackRef.current.fn(path)
-      )
+      window.electron.watchFileOn(path, (_eventType: string, path: Path) => {
+        callbackRef.current.fn(path).catch(reportRejection)
+      })
     }
     setDependencyArrayTracked(pathsRemaining.concat(pathsAdded))
-  }, [difference(dependencyArray, dependencyArrayTracked)[0].length !== 0])
+  }, [hasDiff])
 }