fix: use showSaveDialog with promise instead of callback (#1711)

src/renderer/mixins/electron.js

@@ -1,5 +1,5 @@
 import electron from 'electron'
-import { readFile, writeFile } from 'fs'
+import { readFile, writeFileSync } from 'fs'
 
 export default {
   methods: {
@@ -12,25 +12,20 @@ export default {
       win.reload()
     },
 
-    electron_writeFile (raw, defaultPath, options = {}) {
-      const filters = options.filters || [
-        { name: 'JSON', extensions: ['json'] },
-        { name: 'All Files', extensions: ['*'] }
-      ]
+    async electron_writeFile (raw, defaultPath, options = {}) {
+      const { filePath } = await electron.remote.dialog.showSaveDialog({
+        defaultPath,
+        filters: options.filters || [
+          { name: 'JSON', extensions: ['json'] },
+          { name: 'All Files', extensions: ['*'] }
+        ]
+      })
 
-      return new Promise((resolve, reject) => {
-        electron.remote.dialog.showSaveDialog({
-          defaultPath,
-          filters
-        }, fileName => {
-          if (!fileName) return
+      if (!filePath) return
 
-          writeFile(fileName, raw, 'utf8', err => {
-            if (err) reject(err)
-            resolve(fileName)
-          })
-        })
-      })
+      writeFileSync(filePath, raw, 'utf8')
+
+      return filePath
     },
 
     electron_readFile (options = {}) {