This method to simulate I discovered reading a blog post by Jake Archibald. I read his blog post: Animated line drawing in SVG (also: Stroke Dash Interpolation, and a practical use of this effect: Among the Oscar Contenders, a Host of Connections) where he describes this clever technique. In short it uses animated dash patterns to simulate that the path is drawn. Here are some letters drawn as you hover over them.
Take a look at vivus.js