Uniform up column animation on Raphael?

Question

JavaScript

How to make the column grow up. Now the bottom right corner is moving along with the animation from left to right.
https://jsfiddle.net/kholmukhamedovme/m4q4Lmbr/

var paper = Raphael("paper", 500, 500);

var bar = paper.path(
    "M 100, 500" +
    "L 200, 450" +
    "L 300, 500" +
    "Z"
).animate({
    path:
        "M 100, 350" +
        "L 200, 300" +
        "L 300, 350" +
        "L 300, 500" +
        "L 100, 500" +
        "Z"
}, 1000).attr("fill", "green").attr("stroke", "none");

Answer 1

Add this little hack

var bar = paper.path(
    "M 100, 500" +
    "L 200, 450" +
    "L 300, 500" + 
    "L 300, 500" + // эта строка
    "Z"
  )

https://jsfiddle.net/beyktkbp/