Serialize settings as JSON when sending them to the main process

src/application-delegate.js

@@ -182,7 +182,7 @@ class ApplicationDelegate {
   async setUserSettings (config) {
     this.pendingSettingsUpdateCount++
     try {
-      await ipcHelpers.call('set-user-settings', config)
+      await ipcHelpers.call('set-user-settings', JSON.stringify(config))
     } finally {
       this.pendingSettingsUpdateCount--
     }

src/main-process/atom-application.js

@@ -559,7 +559,7 @@ class AtomApplication extends EventEmitter {
     }))
 
     this.disposable.add(ipcHelpers.respondTo('set-user-settings', (window, settings) =>
-      this.configFile.update(settings)
+      this.configFile.update(JSON.parse(settings))
     ))
 
     this.disposable.add(ipcHelpers.respondTo('center-window', window => window.center()))