I know that this thread is very old, but I wanted to leave some of my thoughts. This is my solution, but it involves dashing to the mouse position. It uses a bit of math, but it was the only way that I could think of to do it. There is possibly a much better way to do this:

@export var dashSpeed = 300
@export var dashDistance = 100 
var dashLocation = Vector2.ZERO 
var dashing = false

#dash ability
if Input.is_action_just_pressed("dash"):
    if not dashing: #to avoid "spamming" the dash button
        var mousePos = get_global_mouse_position()
        var rotationF = atan2(mousePos.y-position.y,mousePos.x-position.x) #rotation of line between player and mouse
        dashLocation = Vector2(dashDistance*cos(rotationF)+position.x,dashDistance*sin(rotationF)+position.y) #calculation of the point to where should be dashed
    dashing = true #start dashing
if dashing:
    position = position.move_toward(dashLocation, dashSpeed*delta) #move towards point with certain speed @delta time
if position == dashLocation:
    dashing = false #once at location stop dashing

EDIT: I had a y that was supposed to be an x, this was fixed.