core/utils/fs: Check for doc presence when handling trash errors (#2120)

The error message thrown by Electron's `shell.trashItem()` method is
localized on macOS. Therefore, we can't detect missing document error
by matching the error message against a crafted RegExp as this would
mean building a RegExp that matches against every possible language.

e.g. when deleting missing `dir/file.txt`, the message would be:
- in English, `The file « file.txt » doesn't exist`
- in French, `Le fichier « file.txt » n'existe pas`

The only way to be sure `shell.trashItem()` failed because the
document does not exist anymore is to check whether the document
exists or not (minus some potential race condition issues).
This is slightly less efficient but works on all platforms for
every language.

core/utils/fs.js

@@ -5,6 +5,7 @@
 const Promise = require('bluebird')
 const childProcess = require('child_process')
 const { shell } = require('electron')
+const fse = require('fs-extra')
 
 const logger = require('./logger')
 
@@ -18,10 +19,10 @@ const log = logger({
  *
  * Errors are logged, not thrown.
  */
-async function hideOnWindows(path /*: string */) /*: Promise<void> */ {
+async function hideOnWindows(fullpath /*: string */) /*: Promise<void> */ {
   if (process.platform !== 'win32') return
   try {
-    await childProcess.execAsync(`attrib +h "${path}"`)
+    await childProcess.execAsync(`attrib +h "${fullpath}"`)
   } catch (err) {
     log.warn(err)
   }
@@ -41,19 +42,15 @@ async function sendToTrash(fullpath /*: string */) {
   try {
     await shell.trashItem(fullpath)
   } catch (err) {
-    if (
-      err.message === 'Failed to move item to trash' || // Error message on Linux
-      err.message === 'Failed to parse path' || // Error message on Windows
-      /doesn’t exist/.test(err.message) // Error message on macOS
-    ) {
+    if (await fse.exists(fullpath)) {
+      throw err
+    } else {
       const error = new Error()
       error.code = 'ENOENT'
       error.path = fullpath
       error.message = `${error.code}: No such file or directory, sendToTrash '${error.path}'`
       throw error
     }
-
-    throw err
   }
 }