How to prevent vscode's "Format Document" from delete empty lines on typescript and scss files?

I work with Ionic and some of the scss files have this format:

// Ionic Variables and Theming. For more info, please see:
// http://ionicframework.com/docs/v2/theming/
$font-path: "../assets/fonts";

@import "ionic.globals";


// Shared Variables
// --------------------------------------------------
// To customize the look and feel of this app, you can override
// the Sass variables found in Ionic's source scss files.
// To view all the possible Ionic variables, see:
// http://ionicframework.com/docs/v2/theming/overriding-ionic-variables/




// Named Color Variables
// --------------------------------------------------
// Named colors makes it easy to reuse colors on various components.
// It's highly recommended to change the default colors
// to match your app's branding. Ionic uses a Sass map of
// colors so you can add, rename and remove colors as needed.
// The "primary" color is the only required color in the map.

$colors: (
  primary:    #488aff,
  secondary:  #32db64,
  danger:     #f53d3d,
  light:      #f4f4f4,
  dark:       #222
);


// App iOS Variables
// --------------------------------------------------
// iOS only Sass variables can go here




// App Material Design Variables
// --------------------------------------------------
// Material Design only Sass variables can go here

Which I find very easy to understand, the problem is when I add somethings and want to format them, vscode makes this mess:

// Ionic Variables and Theming. For more info, please see:
// http://ionicframework.com/docs/v2/theming/
$font-path: "../assets/fonts";
@import "ionic.globals";
// Shared Variables
// --------------------------------------------------
// To customize the look and feel of this app, you can override
// the Sass variables found in Ionic's source scss files.
// To view all the possible Ionic variables, see:
// http://ionicframework.com/docs/v2/theming/overriding-ionic-variables/
// Named Color Variables
// --------------------------------------------------
// Named colors makes it easy to reuse colors on various components.
// It's highly recommended to change the default colors
// to match your app's branding. Ionic uses a Sass map of
// colors so you can add, rename and remove colors as needed.
// The "primary" color is the only required color in the map.
$colors: ( primary : #488aff, secondary : #32db64, danger : #f53d3d, light : #f4f4f4, dark : #222);
// App iOS Variables
// --------------------------------------------------
// iOS only Sass variables can go here
// App Material Design Variables
// --------------------------------------------------
// Material Design only Sass variables can go here

If there a way to prevent this behavior ? I did not found any preserveNewLines option for scss or javascript files.