Visual Code Studio - включение поддержки автокомплита в js-файлах React.js

settings-visual-studio.txt

You need to change syntax to JavascriptReact.

Also you can make this syntax project default for new js files by creating file: 

.vscode/settings.json  with following content:

  {
    "files.associations": { "*.js": "javascriptreact" }
  }